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Long-term results of prosthetic and non-prosthetic reconstruction for obstructive aorto-iliac disease
EurJ VascSurg6, 53-61 (1992)
Long-term Results of Prosthetic and Non-prosthetic Reconstruction for Obstructive Aorto-iliac Disease Pieter J. van den A k k e r ~, Reinout van S c h i l f g a a r d e 2, Ronald Brand a, J. Hajo van Bockel I and J o h a n L. Terpstra ~ 1Department of Surgery, University Hospital Leiden, The Netherlands, 2Department of Surgery, University Hospital Groningen, Groningen, The Netherlands and 3Department of MedicaI Statistics, University of Leiden, Leiden, The Netherlands In this retrospective study the results of 518 prosthetic aorto-iliac reconstructions (PRS) and of 229 thrombo-endarterectomies (TEA) were evaluated, with inclusion offollow-up results up to 20 years after surgery. Patients in the PRS group had presented with more severe ischaemic symptoms and more extensive arterio-sclerotic obstructions than the patients in the TEA group. Results in the TEA group werefurther analysed according to the extension of arterio-sclerotic disease: there were 93 patients with obstructions limited to the aorta or common iliac arteries and 136 patients with more extensive lesions. Patients with limited obstructions were younger, proportionally more often female, had fewer risk factors, and presented with less severe ischaemic symptoms than patients with more extensive obstructions. Operative mortality and early technical and functional results were similar in the PRS and TEA group, but long-term survival and patency rates were significantly better, and the need for late, additional operations was less in the TEA group. Late functional success rates were similar in both groups. The differences in outcome were explained by patient selection. Within the TEA group significantly superior results regarding survival, patency, need for late, additional surgery, and functional success were observed in the subset of patients with obstructions limited to the aorta or common iliac arteries. Considering these results and the risks inherent in a prosthetic reconstruction, such as prosthetic infection and the chancefor false aneurysms, we advocate the use of an aorto-iliac TEA in properly selected patients. Key Words: Aorto-iliac obstructive disease; Patterns of arteriosclerosis; Endarterectomy; Prosthetic reconstruction; Follow-up study.
Introduction In current clinical practice surgery for aorto-iliac obstructive disease (AIOD) is performed by means of thrombo-endarterectomy (TEA) in the minority of cases, 1-3 and prosthetic reconstruction (PRS) in the majority. 2-s This policy is largely based on the technical difficulties of TEA and on the fact that new obstructions tend to occur in the non-endarterectomised segments. 1"6-11 Furthermore, percutaneous transluminal angioplasty (PTA) is now often carried out in patients formerly considered suitable candidates for TEA. 12-14 However, for properly selected patients good results of TEA have been reported many times. 1-3,10,15,16 The present study focuses on the results of TEA, with inclusion of follow-up data up to 20 years after surgery, while the results of PRS are synchronously Please address all correspondenceto: P. J. van den Akker, Medisch Centrum Alkmaar, afdelingChirurgie, Wilhelminalaan 12, 1815JD Alkmaar, The Netherlands. 0950-821X/92/010053+09$03.00/0© 1992Grune & StrattonLtd.
presented to display our approach to reconstructive surgery for AIOD. In the early years, TEA was the preferred method of reconstruction for all patients with AIOD, but in later years TEA has largely been restricted to patients with obstructions confined to the distal aorta and common iliac arteries. Special attention is given to this category of patients with limited obstructions, which represent a specific pattern of arteriosclerotic disease. 1,17
Materials and M e t h o d s Patients, patient characteristics, and presenting symptoms From 1958 to 1980 a total of 747 consecutive patients u n d e r w e n t reconstructive surgery for symptomatic AIOD at our institution. Prosthetic reconstructive surgery was performed in 518 cases (69.3%) and thrombo-endarterectomy in 229 cases (30.7%). In all
P . J . van den Akker et aL
54
Table 1. Patient characteristics according to type of operation
PRS (n=518)
TEA (n=229)
No. %
No. %
p-Value
55.7
51.6
<0.001
Mean age (years)
Table 2. Distribution of presenting symptoms and angiographic findings according to the type of operation
PRS
0.004
TEA
No.
%
No.
%
Presenting symptoms Claudication > 100 m
163
31.4
91
39.5
Claudication < 100m
237
45.8
94
41.2
Critical ischaemia
118
22.8
44
19.3
49
9.5
93
40.6
Male
472 91.1 192 83.8
Abnormal ECG*
129 25.5 37 17.3 0.008
Hypertensiont
161 31.2 65 28.4
N.S.
Hypercholesterolaemia:~
127 28.7 61 30.8
N.S.
Chronic obstructive lung disease 68 13.2 31 13.6
N.s.
Extended central disease
187
36.1
38
16.6
Impaired renal function§
51
9.9
15
6.5
N.S.
Multi-level disease
282
54.4
98
42.8
Diabetes mellitus
38
7.4
13
5.7
N.S.
Angina pectoris
22
4.3
13
5.7
N.S.
Cerebrovascular accidents¶
17
3.3
3
1.3
N.S.
Buerger's disease/vasculitis
4
0.8
5
2.2
N.S.
* Including myocardial infarction, coronary ischemia, and arrhythmias. t Diastolic pressure above 100 mmHg. Fasting plasma cholesterol level above 8.0 mmol 1-1. § Serum creatinine levels above 110 ~mol 1-1. ¶ Including transient ischemic attacks, strokes, and apoplexies.
instances this w a s the p a t i e n t ' s first aorto-iliac reconstructive procedure. Previous reconstructive s u r g e r y for infra-inguinal obstructions h a d b e e n p e r f o r m e d in 16 patients (3.1%) in the PRS g r o u p a n d in five (2.2%) in the TEA group. Patient characteristics are pres e n t e d in Table 1, s h o w i n g that patients in the PRS g r o u p w e r e significantly older a n d m o r e often male, a n d p r e s e n t e d m o r e frequently w i t h an a b n o r m a l ECG t h a n in the TEA group. All 747 patients h a d h a d ischaemic s y m p t o m s due to obstructive arterial disease. A s s e s s m e n t of the severity of ischaemia w a s b a s e d u p o n a n a m n e s t i c a n d physical findings. More objective quantitative m e a s u r e m e n t s are not included in the p r e s e n t analysis, because such tests w e r e only p e r f o r m e d after 1978, w h e n our vascular laboratory b e c a m e operational. Disabling claudication w a s the m o s t frequent p r e s e n t i n g s y m p t o m in b o t h g r o u p s (77.2% in the PRS group, a n d 80.7% in the TEA group). These patients w e r e further categorised according to the claudication distance (CD), w h i c h w a s defined as the range, in metres, that a patient could w a l k at his o w n s p e e d w i t h o u t pain (Table 2). The o t h e r patients pres e n t e d w i t h critical ischaemia, w h i c h w a s defined as the p r e s e n c e of rest-pain or n o n - h e a l i n g ulcers. T h e s e Eur J Vasc Surg Vol 6, January 1992
Angiographic findings Limited central disease
ciata indicate that severe ischaemic s y m p t o m s w e r e m o r e often p r e s e n t in the PRS g r o u p t h a n in the TEA g r o u p (Armitage test, p = 0.05). All patients w e r e subjected to a n g i o g r a p h y prior to surgery. Obstructions w e r e considered h a e m o d y n a m i c a l l y significant if the l u m e n d i a m e t e r w a s r e d u c e d b y m o r e t h a n 75%. A n g i o g r a p h i c findings s e r v e d to classify the patients into the following three categories: 1 (1) "limited central disease" (LCD) if all significant obstructions w e r e confined to the distal aorta a n d c o m m o n iliac arteries; (2) " e x t e n d e d central d i s e a s e " (ECD) if the external iliac arteries w e r e also involved; a n d (3) "multi-level disease" (MLD) if aorto-iliac a n d femoro-popliteal obstructions w e r e s i m u l t a n e o u s l y present. The distribution of these categories is p r e s e n t e d in Table 2, s h o w i n g that extensive obstructions w e r e p r e s e n t significantly m o r e often in the PRS g r o u p t h a n in the TEA group. This, of course, is explained b y the fact that the choice b e t w e e n PRS a n d TEA w a s to a large extent b a s e d on the extension of obstructive disease. In order to evaluate l o n g - t e r m results p r a g m a t i cally, the patients in the TEA g r o u p w e r e categorised into two subsets on the basis of the angiographic d e m o n s t r a t i o n of either limited disease (TEA-lim) or e x t e n d e d a n d multilevel disease (TEA-ext). The T E A - l i m subset is c o m p o s e d of the 93 patients of the TEA g r o u p w i t h LCD (40.6%). The T E A - e x t subset c o m p r i s e s the other 136 patients of the TEA g r o u p (59.4%), of w h o m 38 patients h a d ECD a n d 98 patients MLD. Patient characteristics for b o t h subsets are listed in Table 3, s h o w i n g that patients in the T E A - l i m subset w e r e y o u n g e r , p r o p o r t i o n a l l y m o r e often female, a n d less often p r e s e n t e d with cardiovascular risk factors or associated diseases as comp a r e d w i t h the T E A - e x t subset (p = 0.05). Previous reconstructive surgery for infra-inguinal obstructions
Prosthetic and Non-prosthetic Aorto-iliac Surgery
Selection for operation and operative procedures
Table 3. Patient characteristics according to extension of obstructions in the TEA subset
TEA-lim (n = 93)
TEA-ext (n = 136)
No.
No.
Mean age (years)
%
48.5
Male
%
53.6
74
79.6
118 86.7
9
10.0
28 20.5
Hypertensiont
22
23.7
43
Hypercholesterolaemia~
29
38.2
32 26.2
Chronic obstructive lung disease
9
9.8
22
16.2
Impaired renal function§
3
3.3
12
8.8
Diabetes mellitus
3
3.2
10
7.4
Angina pectoris
3
3.2
10
7.4
Cerebrovascular accidents¶
1
1.1
2
1.5
5
3.7
Abnormal ECG*
Buerger's disease/vasculitis
31.6
* Including myocardial infarction, coronary ischaemia, and arrhythmias. t Diastolic pressure above 100 mmHg. Fasting plasma cholesterol level above 8.0mmol 1. § Serum creatinine levels above II0 fxmol 1-I. ¶ Including transient ischaemic attacks, strokes, and apoplexies.
had been performed in only five patients in the TEAext subset. Disabling claudication was present in 93.5% of the TEA-lim subset, and in 72.1% of the TEA-ext subset. Critical ischaemia had been present in the other patients. These data indicate that severe ischaemic symptoms were more often present in the TEA-ext subset than in the TEA-lim subset (Armirage test, p < 0.001).
55
All patients with intermittent claudication had been subjected to a conservative regimen for at least 6 months prior to surgery. This regimen included walking exercises, oral anti-coagulants and advice to stop smoking. Patients with intermittent claudication were only selected for operation when conservative treatment had failed to improve the CD sufficiently. Patients with critical ischaemia were treated primarily by reconstructive surgery, and not subjected to an initially conservative approach. As illustrated by Figure 1, the number of TEA procedures, compared with PRS procedures, was proportionally greater in the early years than in the later years. This changed in the early 1960s, @hen reliable vascular prostheses became available. Nevertheless, over the years we have maintained the strategy of avoiding the insertion of a prosthesis in cases with LCD which could readily be treated with TEA. The variety of surgical procedures applied in all patients is listed in Table 4. Table 4. Types of primary reconstructions
Type of reconstruction
No.
Thrombo-endarterectomy
229
30.7
Prosthetic reconstructions: Aorta-bi-iliac
339
45.4
Aorta-ilio-femoral
59
7.9
Aorta-bi-femoral
48
6.4
Unilateral prosthesis*
72
9.6
747
100.0
Total
%
* Aorto-iliac, aorto-femoral, ilio-iliac and ilio-femoral prostheses.
40
30-
0
58 59 60 61 62 63 64 65 66 67 68 69 ?0 71 72 73 74 75 76 77 78 79 80 Year of operation
Fig. 1. Distribution of types of aorto-iliac reconstruction in eacll year of the period under study. B, TEA; E~, PRS. Eur J Vasc Surg Vol 6, January 1992
P . J . van den A k k e r et aL
56
Local reconstructions at the level of the femoral bifurcation were performed in 135 patients (26.1%) in the PRS group, and in 50 patients (21.8%) in the TEA-ext subset, with the objective of improving the outflow of the aorto-iliac reconstructions. Simultaneous femoro-popliteal procedures were carried out in nine cases (1.7%) in the PRS group and in four cases (1.7%) in the TEA-ext subset. Lumbar sympathectomies were routinely carried out when significant femoro-popliteal obstructions were present, until the limitations of this policy were recognised.18' 19 Simultaneous renal artery reconstructions for reno-vascular hypertension were performed in 13 patients, 2° of which 12 were in the PRS group. Finally, one reconstruction of the superior mesenteric artery was performed in a patient (PRS group) whose coeliac trunk and inferior mesenteric artery were also occluded. All patients received perioperative antibiotic prophylaxis, the type and the duration of which varied with time. Unless contraindicated after operation, all patients were given oral anti-coagulants (Coumadin, DuPont Laboratories, Wilmington, DE) that were continued in principle for the patient's lifetime, under strict control of the thrombosis centres that are organised by the Dutch Federation of Thrombosis Services. m
*.~
IOO °°o~,~,°°°°°°
,,°°°°°°o°
500 N
"-----'.',-. " """ " :
\
2 400.~ g
.~ o o_
o~ o
80
\
=
~ \
60
\
300-
\
8
\ X\
"6d 200 ~
xx...\
i
0
~
i
I
i
]
]
I
I
I
I
I
I
I
I
I
l
l
5
I0 15 20 Years after operation Fig. 2. Numbers of patients in study and completeness of followup, calculated as the quotient of the number of patients in the
study and the number of all patients alive, at variousintervalsafter operation for each group under study. . . . . . completeness, TEA; . . . . , completeness, PRS; . . . . , number of patients in study, PRS; , number of patients in study, TEA. postoperative intervals and the number of all patients alive at the same time. Numbers of patients in the study and completeness of follow-up during the complete period under study are presented in Figure 2 for both the PRS group and the TEA group.
Methods and completeness of follow-up Data management, parameters of success and statistics Patients were routinely seen at 3, 6, 12 and 24 months after operation and then at 2-year intervals for the rest of their lives. Ultrasound studies were routinely performed from 1978 onwards to check all prosthesisto-artery anastomoses. Angiography was performed when ultrasound studies were of poor quality, w h e n serious complications were suspected, or when a reoperation was considered. Re-operations were performed for progression or recurrence of obstructive lesions, resulting in severe claudication or limb threatening ischaemia, and, of course, for late complications such as false aneurysms and prosthetic infections. The present study was confined to an observation period up to 31 December 1984. We could judge the completeness of individual follow-up data because definitive information on late deaths could be retrieved from the local municipal administrations for all but seven patients (four in the PRS group, and three in the TEA group), who had left the country. Completeness of follow-up data was defined as the quotient of the number of patients in the study (still fulfilling their routine follow-up schedule) at various Eur J VascSurgVol 6, January1992
All clinical data were stored in our computerised vascular registry, details of which have been described elsewhere. 22 Individual data items were checked for validity. Consistency checking was performed on groups of data items that were known to be mutually dependent, e.g. progression of dates of birth, operation, discharge, follow-up visits and death. Patency of aorto-iliac vessels was assessed by the presence or absence of palpable pulses in the groin and if femoral pulses were absent or weak, patency was evaluated by means of angiography. Primary patency rates were based on aorto-iliac patency during the period starting with the dismissal from the first hospital stay and ending when one of the following events occurred: a late re-operation for progressive obstructive disease or for complications of the initial procedures; loss to follow-up; death; closure of the study. Thus, these primary patency rates neglect early thromboses of the reconstructions which could be repaired during the first hospital stay. Secondary patency rates were based on the latest known status of aorto-iliac patency and, consequently, include the
Prosthetic and Non-prosthetic Aorto-iliac Surgery
effects of the late re-operations, irrespective of the indications for these re-operations. Functional results were d e t e r m i n e d on the basis of the severity of ischaemic s y m p t o m s at any interval after operation. These s y m p t o m s were classified into one of five categories of increasing levels of severity: no claudication; mild (CD more than 500 m); m o d e r ate (CD 100-500 m); severe claudication (CD less t h a n 100m); critical ischaemia or amputation. Functional success, at any interval, was defined as an u p w a r d categorical shift; functional failure was defined as no categorical shift or a d o w n w a r d shift, implying relapse to the initial level of s y m p t o m s or worse. For all these calculations the effects of late re-operations were included. Actuarial curves with various e n d p o i n t s (mortality, late reoperation, primary and s e c o n d a r y patency or aorto-iliac segments, and functional success) were calculated according to the standard method of life-table construction, 23"24 censored b y mortality for all analyses except the survival analysis. The life-tables were obtained in tabular form, for each endpoint and each subset of patients, but they are presented here in graphic f o r m only. Comparison of survival curves of the two groups was performed by using the L e e - D e s u test statistic, which closely resembles the log-rank test for K a p l a n Meier estimates. Means were c o m p a r e d by Student's t-test. For comparison of proportions in two by two tables the chi-squared test was used, or, in the case of small numbers, Fisher's exact test. As a test for trend in three or more proportions the Armitage test was used.
Results
Operative results During first hospital stay, 17 (3.3%) patients in the PRS group, and three (1.3%) patients in the TEA group died. Causes of death were cardiac failure in six patients (of which one case was in the T E A - e x t subset); renal failure in five patients; uncontrollable bleeding in three patients (of which one case was in the TEA-ext subset and one case in the T E A - l i m subset); intestinal ischaemia in three patients; a n d other causes in three patients. Early re-interventions for various reasons, such as thrombosis of the reconstruction, persisting critical ischaemia or haemorrhage, were necessary in 63 (12.2%) patients in the PRS group, and in 19 (8.3%) in the TEA group [of which eight (8.6%) were in the TEA-lira subset]. In seven cases with early throm-
57
bosis of the reconstruction [of which six were in the PRS g r o u p (1.2%), and one in the T E A - e x t subset (0.7%)], we refrained from re-operation because the patient either refused or was considered unfit to be subjected to re-operation. These cases were r e g a r d e d as technical failures. Early functional failure was present in 12 (2.4%) patients in the PRS group, and in six (2.6%) patients in the TEA g r o u p (all in the T E A - e x t subset). Functional failure was the result of technical failure or, in the cases of technical success, of an inaccurate diagnosis because femoro-popliteal rather than aorto-iliac obstructive disease had p r o v o k e d the ischaemic s y m p t o m s . Major amputations, within 3 m o n t h s of aorto-iliac reconstruction, had to be p e r f o r m e d in two patients (0.4%) in the PRS g r o u p and in five (2.2%) in the TEA group. All of these patients p r e s e n t e d with g a n g r e n e due to MLD, and their aorto-iliac reconstructions h a d b e e n technically successful.
Long-term survival In addition to the 20 operative deaths, 332 patients died d u r i n g the period u n d e r study, of which 238 (46%) were in the PRS g r o u p and 94 (41%) were in the Table 5. Causes of late deaths according type of primary reconstruction
PRS
TEA
Cause of death
No.
Cardiac death
46
29.5
20
34.5
Malignancy
40
25.6
15
25.8
Sudden death
17
10.9
2
3.5
Cerebral death*
11
7.1
7
12.1
Gastrointestinalt
9
5.8
5
8.6
Ruptured false aneurysm
6
3.8
3
5.2
Reoperation-related:~
7
4.5
2
3.5
Prosthetic infection Respiratory failure
8 3
5.1 1.9
-1
-1.7
Various§
9
5.8
3
5.2
156
100.0
58
100.0
Total
%
No.
%
* Cerebro-vascular accidents, and apoplexies. t Gastric bleeding, and peritonitis. :~ Renal failure, adhesional ileus, and venous thrombo-embolic complications. § Trauma, diabetic coma, hepatic failure, urosepsis, aortic aneurysm, and various. Eur J Vasc Surg Vol 6, January 1992
P.J. van den Akker et al.
58
Long-term complicationsand operations
TEA group. Causes of late deaths were retrievable a n d accepted as valid in 156 (65%) cases in the PRS g r o u p and in 58 (62%) in the TEA g r o u p (Table 5). Causes of death w h i c h were directly or indirectly associated with the vascular reconstruction, such as r u p t u r e d false a n e u r y s m s , prosthetic infections, a n d re-operation related causes, a d d e d u p to 13.4% of all causes of late death in the PRS g r o u p a n d u p to 8.7% in the TEA g r o u p (p = 0.24). " S u d d e n d e a t h " was more often f o u n d in the PRS g r o u p (10.9%) than in the TEA g r o u p (3.5%). This category m a y well include a n u m b e r of u n r e c o g n i s e d r u p t u r e d false a n e u r y s m s . 25 C o m p a r i s o n of actuarial survival in b o t h g r o u p s (Fig. 3) s h o w s a significant difference in favour of the TEA g r o u p (p < 0.001).
,oo
80
D u r i n g long-term follow-up, the n u m b e r of late additional operations p e r f o r m e d for progressive obstructive disease or for complications of the reconstructive p r o c e d u r e s was larger in the PRS g r o u p (172 p r o c e d u r e s in 117 of all 501 survivors, 23.4%), than in the TEA g r o u p (50 p r o c e d u r e s in 35 of all 226 survivors, 15.5%). The indications for these operations are listed in Table 6. Re-operations for aorto-iliac or infrainguinal (re-)obstruction were only carried out if critical ischaemia was present, or if justified b y disabling claudicat~on. False a n e u r y s m s only d e v e l o p e d in patients with a vascular prosthesis, w h e t h e r inserted in the first instance or as a secondary p r o c e d u r e following an initial TEA. 2s The same holds true for prosthetic infections, w h i c h were observed in 10 patients (1.9% of all survivors in the PRS group). In six of these patients a re-operation was performed, with operative mortality in four of them. The other four patients died before a re-operation could be carried out. The actuarial chance of being subjected to a n y type of late re-operation for survivors of an aorto-iliac reconstruction !s-i~resented in Figure 4. This chance is significantly greater in the PRS g r o u p than in the TEA g r o u p (p = 0.002).
•
60
~
4o o_
i No. en'~ering intervol 20 i 2 2 9 196 ! 518 589
0
5
126 219 I0 Yeors offer opera'tiOn
72 I00
30 25
15
20
Fig. 3. Cumulative patient survival after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; , PRS.
Table 6. Indications for late, additional operations in different subsets of the population
PRS Patients
TEA Procedures
Patients
Procedures
Indication for reoperation
No.
%*
No.
No.
%*
No.
pWalue
Aorto-iliac re-obstruction
66
13.2
82
21
9.3
27
N.s.
Infrainguinal obstruction
25
5.0
31
12
5.3
18
N.S.
False aneurysm
44
8.8
52
5
2.2
5
Prosthetic infection
6
1.2
6
--
--
--
N.S.
Hydronephrosis
1
0.2
1
--
--
--
N.S.
Total
142t
172
38:[:
= 0.001
50
* Percentage of all survivors of the primary reconstruction in this subset requiring at least one secondary procedure for the specific indication. f Twenty-five patients were included twice because they were subjected to re-operations for two different indications. :~Three patients were included twice because they were subject to re-operations for two different indications. Eur J VascSurg Vol 6, January 1992
Prosthetic and Non-prosthetic Aorto-iliac Surgery
59
I00 .2 80
No. enferinginterval 501 522 226 17l
153 I00
62 49
I0 15
g 80 ¸
0
~ 60;
60
&
_o ~ 40~ >1
>,
/
~ 2o
/
~
/r
| No. entering interval 20 i 2 2 6 145 501 290
..... n
i
5
:
;
i
I
I0 Years after operation
I
4oi J
I
15
~
20
Fig. 4. Actuarial incidence of late re-operations for various indications after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; - - - , PRS.
i
I
i
0
I
I
78
55 47
124 i
l
i
J|0
i
I
i
I
5
14 8
~ _
15
20
Years after operation
Fig. 5. Cumulative primary patency after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; - - - , PRS.
I00 ~
..........
Long-term technical and functional results c
8O
The primary patency curves show a re-occlusion rate of about 10.5% per 5 years after operation in the PRS group, and of about 7% in the TEA group (Fig. 5), a statistically significant difference (p = 0.05). Longterm patency was markedly extended by late reoperations. The secondary patency curves (Fig. 6), thus including the effects of these procedures, show eventual re-occlusion rates of about 5% per 5 years in the PRS group, and of about 3.5% in the TEA group, a statistically insignificant difference (p = 0.07). A question of critical importance from the patient's point of view is his chance of actually benefiting from the surgical procedure at any time period after operation. In order to clarify this question, the curves expressing functional success are presented in Figure 7. There was no statistically significant difference, since the functional failure rate was about 7% per 5 years after operation in both groups. During the years of long-term follow-up, a major amputation had to be performed in 23 cases in the PRS group (4.6% of all survivors in this group). In 17 cases (3.4%) this was due to aorto41iac re-obstruction and in six cases (1.2%) to progressions of femoropopliteal disease. In the TEA group six amputations (2.6%) had to be performed, of which three (1.3%) were' due to aorto-iliac re-obstruction and three (1.3%) to femoro-popliteal obstruction.
Long-term results in the TEA-lira and TEA-ext subsets In addition to the one operative death in the TEA-lim subset and two operative deaths in the TEA-ext subset, 26 patients (28.0%) in the TEA-lira subset and 68
>,
6O
40
~_
No. entering interval 20 ~ 226 155 501 516 I
0
i
i
I
I
5
91 153 i
I
I
jOI
43 66 I
I
I
~
iS1
18 15 I
I
2kO
Years after operation
Fig. 6. Cumulative secondary patency, thus including the effects of all late re-operations, after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; , PRS.
I00 8O
-~ ~-
60
i
[
"~
40
R
20
o
No. en#ering interval 226 175 501 539
g
108 172 i
i
i
:
59 78 i
~ 1
I0 Years after operation
,
25 24 I
!
i
20
15
Fig. 7. Cumulative functional success in the two groups, according to the type of operation. - - - , TEA; , PRS.
patients (50.0%) ot the TEA-ext subset died during the period under study. The cumulative survival curves for both subsets are presented in Figure 8, showing a highly significant difference in favour of the TEA-lim subset (p = 0.003). Eur J Vasc Surg Vol 6, January 1992
60
P.J. van den Akker etal.
,ooF
_
ischaemic symptoms, and specific cardiovascular and other risk factors were significantly more common in the PRS subset than in the TEA subset. Such characteristics should be regarded as specific expressions of different patterns of arteriosclerotic disease 1"17,26 and imply different risks for all possible future manifestations of this systemic disease. Second, PRS and x:l TEA cannot be regarded as two exchangeable modali~- 20 t No~entering interval ties of treatment. To a great extent, TEA was restric83 51 29 16 /136 ,13 75 43 14 ted to the patients with localised disease, and only /. I I i ] i i i ~ I i i i i I carried out if technically feasible. Consequently, o 5 Io 15 20 patient and treatment selection are an obvious explaYeors offer operofion Fig. 8. Cumulative patient survival after aorto-iliac endarterec- nation for the differences in outcome of the present tomy in two subsets of the thromboendarterectomy-group,accord- analysis. ing to the extension of obstructive disease. ---, TEA-ext; - - , Since such selections have always hampered a TEA-lim. sound comparison of the two operative approaches, 27 considerations other than results of comparative Late, additional operations were necessary in studies serve the purpose of choosing between TEA nine patients of the TEA-Iim subset (i.e. 9.8% of all and PRS. For example, the technical problems of TEA survivors in this subset), and in 26 patients (19.4%) of and the chances of recurrence and progression of disthe TEA-ext subset. The actuarial chance of such pro- ease in the aorto-iliac vessels have been well docucedures was significantly smaller in the TEA-lim mented by many authors 1' 6-11 and have caused many than in the TEA-ext subset (p < 0.001). surgeons to abandon its use. On the other hand, Late aorto-iliac re-obstruction was observed in excellent results of TEA have been reported not five patients (5.4%) in the TEA-lim subset, in all only in the present study but also in many other cases more than 9 years after the primary procedure. studies.l-B, lo,~s, 16 Moreover, notwithstanding the Patency was restored by re-operation in four cases, good results of prosthetic reconstruction, 2-5 the which left only one case with late aorto-iliac re- specific risks of prosthetic implants, such as the obstruction in this subset. In the TEA-ext subset late occurrence of prosthetic infections and the developaorto-iliac re-obstruction occurred in 25 patients ment of false aneurysms 25"28 must be recognised. (18.7%), and re-operations for this indication were These considerations have been the reason over the carried out in 17 cases. These results were associated years for maintaining our strategy of preferentially with significantly better long-term cumulative performing a TEA in patients with localised obstrucpatency curves for the TEA-Iim than for the TEA-ext tive disease, rather than inserting a prosthesis in such subset, both for primary (p < 0.001) and for second- cases. ary patency (p < 0.002). The results of this study contradict the fear that Late functional failure was observed in the TEA- late, additional operations are needed after TEA. We lim subset in six patients (6.5%), in the earliest case 8 found that immediate reinterventions as well as late, years after the primary procedure, and in the TEA- additional operations were more often carried out in ext subset in 20 patients (14.9%), in addition to the six the PRS group than in the TEA group. Survival early functional failures (4.5%). The cumulative func- curves as well as primary and secondary patency tional success curve was significantly better for the curves were better in the TEA group than in the PRS TEA-Iim than for the TEA-ext subset (p < 0.001). group. However, functional results were similar for both groups, which is explained by the equalising effects of collateral bloodflow and of concomitant femoro-popliteal obstructive disease. 29 The positive Discussion effects of patient selection were most prominent when regarding the results in the subset of patients The results as found in this study, should not be within the TEA group with strictly localised obstrucinterpreted as indicating the superiority of TEA over tive disease. The superiority of the results in the PRS as surgical treatment for aorto-iliac obstructive TEA-lim subset over those in the TEA-ext subset disease for two reasons. First, TEA and PRS were was demonstrated by significantly better survival carried out in groups of patients with different char- curves, patency curves, functional success curves, acteristics, since extensive obstructive lesions, severe and the lesser need for late, additional surgery. Eur J VascSurgVol6, January1992
Prosthetic and Non-prosthetic Aorto-iliac Surgery
These considerations indicate that TEA is assodated with excellent results in properly selected patients. The very fact that proper selection, as such, must be interpreted as a factor of importance, also implies that the comparison with PRS is inappropriate. We therefore cannot claim that similar or even better results could have been obtained in these patients with PRS instead of TEA. Thus, we have presented our results of PRS not to serve as a comparison with TEA, but rather to illustrate the relevant background of the overall consequences of our approach to reconstructive surgery for AIOD. We believe that the outcome of our study justifies our strategy of choosing TEA rather than PRS for the treatment of AIOD confined to the aorta and common lilac arteries in selected patients. Finally, the place of PTA for this selected group of patients must be addressed. Short common iliac artery stenoses have been reported to respond well to PTA.12-14 The dilatation of this type of stenosis is associated with a low complication rate and initial technical and functional success rates of about 95%. Long-term patency, however, was found to be only 63% at 5 years in a prospective study of patients with optimal characteristics, i.e. intermittent claudication, common iliac stenoses, and good run-off. Results were markedly worse in cases with critical ischaemia, sites other than the common iliac artery, occlusion instead of stenosis and poor run-off. 12 In selected patients, suitable for PTA and TEA, these factors should be included before a decision about treatment is made.
References 1 BREWSTERDC, DARLING RC. Optimal methods of aortoiliac reconstruction. Surgery 1978; 84: 739-748. 2 CRAWFORDES, BOMBERGERRA, GLAESERDH, SALEHSA, RUSSEL WL. Aortoiliac occlusive disease: factors influencing survival and function following reconstructive operation over a twentyfive year period. Surgery 1981; 90: 1055-1067. 3 SZlLAGYIDE, ELLIOTTJP, SMITHRF, REDDYDJ, MCPHARLINM. A thirty-year survey of the reconstructive surgical treatment of aortoiliac occlusive disease. J Vasc Surg 1986; 3: 421-436. 4 NEVELSTEENA, WOUTERSL, SOY R. Aortofemoral Dacron reconstruction for aorto-iliac occlusive disease: a 25-year survey. Eur J Vasc Surg 1991; 5: 179-186. 5 SLADENJG, GILMOURJL, WONG RW. Cumulative patency and actual palliation in patients with claudication after aortofemoral bypass. Prospective long-term follow-up of 100 patients. Am J Surg 1986; 152: 190-195. 6 SZILAGYIDE, SMITH RF, WHITNEYDG. The durability of aortoiliac endarterectomy. Arch Surg 1964; 89: 827-839. 7 DARLINGRC, LINTON RR. Aortoiliofemoral endarterectomy for atherosclerotic occlusive disease. Surgery 1964; 55: 184-194.
61
8 BUCKBERGGD, HENNEYRP, CANNONJA. Postoperative complications of aortoiliac endarterectomy: incidence, cause, and prevention. Surgery 1968; 63: 121-127. 9 PEROUEGD, LONGWD, SMITHRB. Perspective concerningaortofemoral arterial reconstruction. Ann Surg 1971; 173: 940-944. 10 INAHARA T. Evaluation of endarterectomy for aortoiliac and aortoiliofemoral occlusive disease. Arch Surg 1975; 110: 1458-1464. 11 CRAWFOROES, MANNING, LG, KELLYTF. "Redo" surgery after operations for aneurysm and occlusion of the abdominal aorta. Surgery 1977; 81: 41-52. 12 JOHNSTON KW, RAE M, HOGG-JOHNSTONSA, et al. Five-year results of a prospective study of percutaneous transluminal angioplasty. Ann Surg 1987; 206: 403-413. 13 RUTHERFORDRB, PATTA, KUMPEDA. The current role of percutaneous transluminal angioplasty. In: GREENHALGHRM, JAMIESON CW, NICOLAIDESAN, eds. Vascularsurgery: Issues in Current Practice. London: Grune & Stratton, 1986; 229-244. 14 TEGTMEYER CJ, HARTWELL GD, BAYNE SELBY J, ROBERTSON R, KRON IL, TRIBBLECG. Results and complications of angioplasty in aortoiliac disease. Circulation 1991; 83 suppl. I: 53-60. 15 STAPLE TW. The solitary aortoiliac lesion. Surgery 1968; 64: 569-576. 16 WYLIEEJ, OLCOTTC, STRINGST. Aortoiliac thromboendarterectomy. In: VARCO RL, DELANEYJP, eds. Controversy in Surgery. Philadelphia: WB Saunders, 1976; 437-450. 17 DEBAKEYME, LAWRIEGM, GLAESERDH. Patterns of atherosclerosis and their surgical significance. Ann Surg 1985; 201: 115-131. 18 SATIANIB, LIAPISCD, HAYESJP, KIMMINSS, EVANSWE. Prospective randomized study of concomitant lumbar sympathectomy with aortoiliac reconstruction. Am J Surg 1982; 143: 755-760. 19 CAMPBELL WB. Surgical and chemical sympathectomy. In: GREENHALGHRIVI, ed. Indications in Vascular Surgery. Philadelphia: WB Saunders, 1988; 401-418. 20 VAN BOCKELJH, VAN SCHILFGAARDER, FELTHUISW, HERMANSJ, TERPSTRAJL. Influence of preoperative risk factors and the surgical procedure on surgical mortality in renovascular hypertension. Am J Surg 1988; 155: 770-775. 21 VAN DERMEERFJM, GERRITS-DRABBECW. Therapeutic control of oral anticoagulant treatment in the Netherlands. Am J Clin Pathol 1988; 90: 685-690. 22 VAN DEN AKKERPJ, VANHOCKErJH, BRANDR, VANSCHILEGAARDE R. Computerised vascular data management. A flexible modular registry suitable for the evaluation of long-term results in patients subjected to multiple interventions. Eur J Vasc Surg 1991; 5: 459-465. 23 CUTLER, SJ, EDERER F. Maximum utilization of the life table method in analyzing survival, l Chron Dis 1958; 8: 699-712. 24 STOKESJM, SuGG WL, BUTCHERHR. Standard method of assessing relative effectiveness of therapies for arterial occlusive disease. Ann Surg 1963; 157: 343-350. 25 VAN DEN AKKERPJ, VAN SCHILFGAARDER, BRANDR, VAN BOCKEL JH, TERPSTRAJL. False aneurysms after prosthetic reconstructions for aortoiliac obstructive disease. Ann Surg 1989; 210: 658-666. 26 BREWSTERDC. Clinical and anatomical considerations for surgery in aortoiliac disease and results of surgical treatment, Circulation 1991; 83 (Suppl I): 42-52. 27 NICOLAIOESAN, GRIGGJM. Are there any indications for aortic and iliac endarterectomy? In: GREENHALGHRM, ed. Indications in Vascular Surgery. Philadelphia: WB Saunders, 1988; 201-213. 28 SZILAGYIDE, SMITH RE, ELLIOTTJP, HAGEMANJH, DALL'OLMo CA. Anastomotic aneurysms after vascular reconstruction: problems of incidence, etiology, and treatment. Surgery 1975; 78: 800-816. 29 VAN DEN AKKERPJ, VAN SCHILFGAARDER, BRANDR, VAN BOCKEL JH, TERPSTRAJL. Long-term success of aortoiliac surgery for arteriosclerotic obstructive disease. Surg Gynecol Obstet 1991; in press.
Accepted 8 October 1991
Eur J Vasc Surg Vol 6, January 1992
Long-term Results of Prosthetic and Non-prosthetic Reconstruction for Obstructive Aorto-iliac Disease Pieter J. van den A k k e r ~, Reinout van S c h i l f g a a r d e 2, Ronald Brand a, J. Hajo van Bockel I and J o h a n L. Terpstra ~ 1Department of Surgery, University Hospital Leiden, The Netherlands, 2Department of Surgery, University Hospital Groningen, Groningen, The Netherlands and 3Department of MedicaI Statistics, University of Leiden, Leiden, The Netherlands In this retrospective study the results of 518 prosthetic aorto-iliac reconstructions (PRS) and of 229 thrombo-endarterectomies (TEA) were evaluated, with inclusion offollow-up results up to 20 years after surgery. Patients in the PRS group had presented with more severe ischaemic symptoms and more extensive arterio-sclerotic obstructions than the patients in the TEA group. Results in the TEA group werefurther analysed according to the extension of arterio-sclerotic disease: there were 93 patients with obstructions limited to the aorta or common iliac arteries and 136 patients with more extensive lesions. Patients with limited obstructions were younger, proportionally more often female, had fewer risk factors, and presented with less severe ischaemic symptoms than patients with more extensive obstructions. Operative mortality and early technical and functional results were similar in the PRS and TEA group, but long-term survival and patency rates were significantly better, and the need for late, additional operations was less in the TEA group. Late functional success rates were similar in both groups. The differences in outcome were explained by patient selection. Within the TEA group significantly superior results regarding survival, patency, need for late, additional surgery, and functional success were observed in the subset of patients with obstructions limited to the aorta or common iliac arteries. Considering these results and the risks inherent in a prosthetic reconstruction, such as prosthetic infection and the chancefor false aneurysms, we advocate the use of an aorto-iliac TEA in properly selected patients. Key Words: Aorto-iliac obstructive disease; Patterns of arteriosclerosis; Endarterectomy; Prosthetic reconstruction; Follow-up study.
Introduction In current clinical practice surgery for aorto-iliac obstructive disease (AIOD) is performed by means of thrombo-endarterectomy (TEA) in the minority of cases, 1-3 and prosthetic reconstruction (PRS) in the majority. 2-s This policy is largely based on the technical difficulties of TEA and on the fact that new obstructions tend to occur in the non-endarterectomised segments. 1"6-11 Furthermore, percutaneous transluminal angioplasty (PTA) is now often carried out in patients formerly considered suitable candidates for TEA. 12-14 However, for properly selected patients good results of TEA have been reported many times. 1-3,10,15,16 The present study focuses on the results of TEA, with inclusion of follow-up data up to 20 years after surgery, while the results of PRS are synchronously Please address all correspondenceto: P. J. van den Akker, Medisch Centrum Alkmaar, afdelingChirurgie, Wilhelminalaan 12, 1815JD Alkmaar, The Netherlands. 0950-821X/92/010053+09$03.00/0© 1992Grune & StrattonLtd.
presented to display our approach to reconstructive surgery for AIOD. In the early years, TEA was the preferred method of reconstruction for all patients with AIOD, but in later years TEA has largely been restricted to patients with obstructions confined to the distal aorta and common iliac arteries. Special attention is given to this category of patients with limited obstructions, which represent a specific pattern of arteriosclerotic disease. 1,17
Materials and M e t h o d s Patients, patient characteristics, and presenting symptoms From 1958 to 1980 a total of 747 consecutive patients u n d e r w e n t reconstructive surgery for symptomatic AIOD at our institution. Prosthetic reconstructive surgery was performed in 518 cases (69.3%) and thrombo-endarterectomy in 229 cases (30.7%). In all
P . J . van den Akker et aL
54
Table 1. Patient characteristics according to type of operation
PRS (n=518)
TEA (n=229)
No. %
No. %
p-Value
55.7
51.6
<0.001
Mean age (years)
Table 2. Distribution of presenting symptoms and angiographic findings according to the type of operation
PRS
0.004
TEA
No.
%
No.
%
Presenting symptoms Claudication > 100 m
163
31.4
91
39.5
Claudication < 100m
237
45.8
94
41.2
Critical ischaemia
118
22.8
44
19.3
49
9.5
93
40.6
Male
472 91.1 192 83.8
Abnormal ECG*
129 25.5 37 17.3 0.008
Hypertensiont
161 31.2 65 28.4
N.S.
Hypercholesterolaemia:~
127 28.7 61 30.8
N.S.
Chronic obstructive lung disease 68 13.2 31 13.6
N.s.
Extended central disease
187
36.1
38
16.6
Impaired renal function§
51
9.9
15
6.5
N.S.
Multi-level disease
282
54.4
98
42.8
Diabetes mellitus
38
7.4
13
5.7
N.S.
Angina pectoris
22
4.3
13
5.7
N.S.
Cerebrovascular accidents¶
17
3.3
3
1.3
N.S.
Buerger's disease/vasculitis
4
0.8
5
2.2
N.S.
* Including myocardial infarction, coronary ischemia, and arrhythmias. t Diastolic pressure above 100 mmHg. Fasting plasma cholesterol level above 8.0 mmol 1-1. § Serum creatinine levels above 110 ~mol 1-1. ¶ Including transient ischemic attacks, strokes, and apoplexies.
instances this w a s the p a t i e n t ' s first aorto-iliac reconstructive procedure. Previous reconstructive s u r g e r y for infra-inguinal obstructions h a d b e e n p e r f o r m e d in 16 patients (3.1%) in the PRS g r o u p a n d in five (2.2%) in the TEA group. Patient characteristics are pres e n t e d in Table 1, s h o w i n g that patients in the PRS g r o u p w e r e significantly older a n d m o r e often male, a n d p r e s e n t e d m o r e frequently w i t h an a b n o r m a l ECG t h a n in the TEA group. All 747 patients h a d h a d ischaemic s y m p t o m s due to obstructive arterial disease. A s s e s s m e n t of the severity of ischaemia w a s b a s e d u p o n a n a m n e s t i c a n d physical findings. More objective quantitative m e a s u r e m e n t s are not included in the p r e s e n t analysis, because such tests w e r e only p e r f o r m e d after 1978, w h e n our vascular laboratory b e c a m e operational. Disabling claudication w a s the m o s t frequent p r e s e n t i n g s y m p t o m in b o t h g r o u p s (77.2% in the PRS group, a n d 80.7% in the TEA group). These patients w e r e further categorised according to the claudication distance (CD), w h i c h w a s defined as the range, in metres, that a patient could w a l k at his o w n s p e e d w i t h o u t pain (Table 2). The o t h e r patients pres e n t e d w i t h critical ischaemia, w h i c h w a s defined as the p r e s e n c e of rest-pain or n o n - h e a l i n g ulcers. T h e s e Eur J Vasc Surg Vol 6, January 1992
Angiographic findings Limited central disease
ciata indicate that severe ischaemic s y m p t o m s w e r e m o r e often p r e s e n t in the PRS g r o u p t h a n in the TEA g r o u p (Armitage test, p = 0.05). All patients w e r e subjected to a n g i o g r a p h y prior to surgery. Obstructions w e r e considered h a e m o d y n a m i c a l l y significant if the l u m e n d i a m e t e r w a s r e d u c e d b y m o r e t h a n 75%. A n g i o g r a p h i c findings s e r v e d to classify the patients into the following three categories: 1 (1) "limited central disease" (LCD) if all significant obstructions w e r e confined to the distal aorta a n d c o m m o n iliac arteries; (2) " e x t e n d e d central d i s e a s e " (ECD) if the external iliac arteries w e r e also involved; a n d (3) "multi-level disease" (MLD) if aorto-iliac a n d femoro-popliteal obstructions w e r e s i m u l t a n e o u s l y present. The distribution of these categories is p r e s e n t e d in Table 2, s h o w i n g that extensive obstructions w e r e p r e s e n t significantly m o r e often in the PRS g r o u p t h a n in the TEA group. This, of course, is explained b y the fact that the choice b e t w e e n PRS a n d TEA w a s to a large extent b a s e d on the extension of obstructive disease. In order to evaluate l o n g - t e r m results p r a g m a t i cally, the patients in the TEA g r o u p w e r e categorised into two subsets on the basis of the angiographic d e m o n s t r a t i o n of either limited disease (TEA-lim) or e x t e n d e d a n d multilevel disease (TEA-ext). The T E A - l i m subset is c o m p o s e d of the 93 patients of the TEA g r o u p w i t h LCD (40.6%). The T E A - e x t subset c o m p r i s e s the other 136 patients of the TEA g r o u p (59.4%), of w h o m 38 patients h a d ECD a n d 98 patients MLD. Patient characteristics for b o t h subsets are listed in Table 3, s h o w i n g that patients in the T E A - l i m subset w e r e y o u n g e r , p r o p o r t i o n a l l y m o r e often female, a n d less often p r e s e n t e d with cardiovascular risk factors or associated diseases as comp a r e d w i t h the T E A - e x t subset (p = 0.05). Previous reconstructive surgery for infra-inguinal obstructions
Prosthetic and Non-prosthetic Aorto-iliac Surgery
Selection for operation and operative procedures
Table 3. Patient characteristics according to extension of obstructions in the TEA subset
TEA-lim (n = 93)
TEA-ext (n = 136)
No.
No.
Mean age (years)
%
48.5
Male
%
53.6
74
79.6
118 86.7
9
10.0
28 20.5
Hypertensiont
22
23.7
43
Hypercholesterolaemia~
29
38.2
32 26.2
Chronic obstructive lung disease
9
9.8
22
16.2
Impaired renal function§
3
3.3
12
8.8
Diabetes mellitus
3
3.2
10
7.4
Angina pectoris
3
3.2
10
7.4
Cerebrovascular accidents¶
1
1.1
2
1.5
5
3.7
Abnormal ECG*
Buerger's disease/vasculitis
31.6
* Including myocardial infarction, coronary ischaemia, and arrhythmias. t Diastolic pressure above 100 mmHg. Fasting plasma cholesterol level above 8.0mmol 1. § Serum creatinine levels above II0 fxmol 1-I. ¶ Including transient ischaemic attacks, strokes, and apoplexies.
had been performed in only five patients in the TEAext subset. Disabling claudication was present in 93.5% of the TEA-lim subset, and in 72.1% of the TEA-ext subset. Critical ischaemia had been present in the other patients. These data indicate that severe ischaemic symptoms were more often present in the TEA-ext subset than in the TEA-lim subset (Armirage test, p < 0.001).
55
All patients with intermittent claudication had been subjected to a conservative regimen for at least 6 months prior to surgery. This regimen included walking exercises, oral anti-coagulants and advice to stop smoking. Patients with intermittent claudication were only selected for operation when conservative treatment had failed to improve the CD sufficiently. Patients with critical ischaemia were treated primarily by reconstructive surgery, and not subjected to an initially conservative approach. As illustrated by Figure 1, the number of TEA procedures, compared with PRS procedures, was proportionally greater in the early years than in the later years. This changed in the early 1960s, @hen reliable vascular prostheses became available. Nevertheless, over the years we have maintained the strategy of avoiding the insertion of a prosthesis in cases with LCD which could readily be treated with TEA. The variety of surgical procedures applied in all patients is listed in Table 4. Table 4. Types of primary reconstructions
Type of reconstruction
No.
Thrombo-endarterectomy
229
30.7
Prosthetic reconstructions: Aorta-bi-iliac
339
45.4
Aorta-ilio-femoral
59
7.9
Aorta-bi-femoral
48
6.4
Unilateral prosthesis*
72
9.6
747
100.0
Total
%
* Aorto-iliac, aorto-femoral, ilio-iliac and ilio-femoral prostheses.
40
30-
0
58 59 60 61 62 63 64 65 66 67 68 69 ?0 71 72 73 74 75 76 77 78 79 80 Year of operation
Fig. 1. Distribution of types of aorto-iliac reconstruction in eacll year of the period under study. B, TEA; E~, PRS. Eur J Vasc Surg Vol 6, January 1992
P . J . van den A k k e r et aL
56
Local reconstructions at the level of the femoral bifurcation were performed in 135 patients (26.1%) in the PRS group, and in 50 patients (21.8%) in the TEA-ext subset, with the objective of improving the outflow of the aorto-iliac reconstructions. Simultaneous femoro-popliteal procedures were carried out in nine cases (1.7%) in the PRS group and in four cases (1.7%) in the TEA-ext subset. Lumbar sympathectomies were routinely carried out when significant femoro-popliteal obstructions were present, until the limitations of this policy were recognised.18' 19 Simultaneous renal artery reconstructions for reno-vascular hypertension were performed in 13 patients, 2° of which 12 were in the PRS group. Finally, one reconstruction of the superior mesenteric artery was performed in a patient (PRS group) whose coeliac trunk and inferior mesenteric artery were also occluded. All patients received perioperative antibiotic prophylaxis, the type and the duration of which varied with time. Unless contraindicated after operation, all patients were given oral anti-coagulants (Coumadin, DuPont Laboratories, Wilmington, DE) that were continued in principle for the patient's lifetime, under strict control of the thrombosis centres that are organised by the Dutch Federation of Thrombosis Services. m
*.~
IOO °°o~,~,°°°°°°
,,°°°°°°o°
500 N
"-----'.',-. " """ " :
\
2 400.~ g
.~ o o_
o~ o
80
\
=
~ \
60
\
300-
\
8
\ X\
"6d 200 ~
xx...\
i
0
~
i
I
i
]
]
I
I
I
I
I
I
I
I
I
l
l
5
I0 15 20 Years after operation Fig. 2. Numbers of patients in study and completeness of followup, calculated as the quotient of the number of patients in the
study and the number of all patients alive, at variousintervalsafter operation for each group under study. . . . . . completeness, TEA; . . . . , completeness, PRS; . . . . , number of patients in study, PRS; , number of patients in study, TEA. postoperative intervals and the number of all patients alive at the same time. Numbers of patients in the study and completeness of follow-up during the complete period under study are presented in Figure 2 for both the PRS group and the TEA group.
Methods and completeness of follow-up Data management, parameters of success and statistics Patients were routinely seen at 3, 6, 12 and 24 months after operation and then at 2-year intervals for the rest of their lives. Ultrasound studies were routinely performed from 1978 onwards to check all prosthesisto-artery anastomoses. Angiography was performed when ultrasound studies were of poor quality, w h e n serious complications were suspected, or when a reoperation was considered. Re-operations were performed for progression or recurrence of obstructive lesions, resulting in severe claudication or limb threatening ischaemia, and, of course, for late complications such as false aneurysms and prosthetic infections. The present study was confined to an observation period up to 31 December 1984. We could judge the completeness of individual follow-up data because definitive information on late deaths could be retrieved from the local municipal administrations for all but seven patients (four in the PRS group, and three in the TEA group), who had left the country. Completeness of follow-up data was defined as the quotient of the number of patients in the study (still fulfilling their routine follow-up schedule) at various Eur J VascSurgVol 6, January1992
All clinical data were stored in our computerised vascular registry, details of which have been described elsewhere. 22 Individual data items were checked for validity. Consistency checking was performed on groups of data items that were known to be mutually dependent, e.g. progression of dates of birth, operation, discharge, follow-up visits and death. Patency of aorto-iliac vessels was assessed by the presence or absence of palpable pulses in the groin and if femoral pulses were absent or weak, patency was evaluated by means of angiography. Primary patency rates were based on aorto-iliac patency during the period starting with the dismissal from the first hospital stay and ending when one of the following events occurred: a late re-operation for progressive obstructive disease or for complications of the initial procedures; loss to follow-up; death; closure of the study. Thus, these primary patency rates neglect early thromboses of the reconstructions which could be repaired during the first hospital stay. Secondary patency rates were based on the latest known status of aorto-iliac patency and, consequently, include the
Prosthetic and Non-prosthetic Aorto-iliac Surgery
effects of the late re-operations, irrespective of the indications for these re-operations. Functional results were d e t e r m i n e d on the basis of the severity of ischaemic s y m p t o m s at any interval after operation. These s y m p t o m s were classified into one of five categories of increasing levels of severity: no claudication; mild (CD more than 500 m); m o d e r ate (CD 100-500 m); severe claudication (CD less t h a n 100m); critical ischaemia or amputation. Functional success, at any interval, was defined as an u p w a r d categorical shift; functional failure was defined as no categorical shift or a d o w n w a r d shift, implying relapse to the initial level of s y m p t o m s or worse. For all these calculations the effects of late re-operations were included. Actuarial curves with various e n d p o i n t s (mortality, late reoperation, primary and s e c o n d a r y patency or aorto-iliac segments, and functional success) were calculated according to the standard method of life-table construction, 23"24 censored b y mortality for all analyses except the survival analysis. The life-tables were obtained in tabular form, for each endpoint and each subset of patients, but they are presented here in graphic f o r m only. Comparison of survival curves of the two groups was performed by using the L e e - D e s u test statistic, which closely resembles the log-rank test for K a p l a n Meier estimates. Means were c o m p a r e d by Student's t-test. For comparison of proportions in two by two tables the chi-squared test was used, or, in the case of small numbers, Fisher's exact test. As a test for trend in three or more proportions the Armitage test was used.
Results
Operative results During first hospital stay, 17 (3.3%) patients in the PRS group, and three (1.3%) patients in the TEA group died. Causes of death were cardiac failure in six patients (of which one case was in the T E A - e x t subset); renal failure in five patients; uncontrollable bleeding in three patients (of which one case was in the TEA-ext subset and one case in the T E A - l i m subset); intestinal ischaemia in three patients; a n d other causes in three patients. Early re-interventions for various reasons, such as thrombosis of the reconstruction, persisting critical ischaemia or haemorrhage, were necessary in 63 (12.2%) patients in the PRS group, and in 19 (8.3%) in the TEA group [of which eight (8.6%) were in the TEA-lira subset]. In seven cases with early throm-
57
bosis of the reconstruction [of which six were in the PRS g r o u p (1.2%), and one in the T E A - e x t subset (0.7%)], we refrained from re-operation because the patient either refused or was considered unfit to be subjected to re-operation. These cases were r e g a r d e d as technical failures. Early functional failure was present in 12 (2.4%) patients in the PRS group, and in six (2.6%) patients in the TEA g r o u p (all in the T E A - e x t subset). Functional failure was the result of technical failure or, in the cases of technical success, of an inaccurate diagnosis because femoro-popliteal rather than aorto-iliac obstructive disease had p r o v o k e d the ischaemic s y m p t o m s . Major amputations, within 3 m o n t h s of aorto-iliac reconstruction, had to be p e r f o r m e d in two patients (0.4%) in the PRS g r o u p and in five (2.2%) in the TEA group. All of these patients p r e s e n t e d with g a n g r e n e due to MLD, and their aorto-iliac reconstructions h a d b e e n technically successful.
Long-term survival In addition to the 20 operative deaths, 332 patients died d u r i n g the period u n d e r study, of which 238 (46%) were in the PRS g r o u p and 94 (41%) were in the Table 5. Causes of late deaths according type of primary reconstruction
PRS
TEA
Cause of death
No.
Cardiac death
46
29.5
20
34.5
Malignancy
40
25.6
15
25.8
Sudden death
17
10.9
2
3.5
Cerebral death*
11
7.1
7
12.1
Gastrointestinalt
9
5.8
5
8.6
Ruptured false aneurysm
6
3.8
3
5.2
Reoperation-related:~
7
4.5
2
3.5
Prosthetic infection Respiratory failure
8 3
5.1 1.9
-1
-1.7
Various§
9
5.8
3
5.2
156
100.0
58
100.0
Total
%
No.
%
* Cerebro-vascular accidents, and apoplexies. t Gastric bleeding, and peritonitis. :~ Renal failure, adhesional ileus, and venous thrombo-embolic complications. § Trauma, diabetic coma, hepatic failure, urosepsis, aortic aneurysm, and various. Eur J Vasc Surg Vol 6, January 1992
P.J. van den Akker et al.
58
Long-term complicationsand operations
TEA group. Causes of late deaths were retrievable a n d accepted as valid in 156 (65%) cases in the PRS g r o u p and in 58 (62%) in the TEA g r o u p (Table 5). Causes of death w h i c h were directly or indirectly associated with the vascular reconstruction, such as r u p t u r e d false a n e u r y s m s , prosthetic infections, a n d re-operation related causes, a d d e d u p to 13.4% of all causes of late death in the PRS g r o u p a n d u p to 8.7% in the TEA g r o u p (p = 0.24). " S u d d e n d e a t h " was more often f o u n d in the PRS g r o u p (10.9%) than in the TEA g r o u p (3.5%). This category m a y well include a n u m b e r of u n r e c o g n i s e d r u p t u r e d false a n e u r y s m s . 25 C o m p a r i s o n of actuarial survival in b o t h g r o u p s (Fig. 3) s h o w s a significant difference in favour of the TEA g r o u p (p < 0.001).
,oo
80
D u r i n g long-term follow-up, the n u m b e r of late additional operations p e r f o r m e d for progressive obstructive disease or for complications of the reconstructive p r o c e d u r e s was larger in the PRS g r o u p (172 p r o c e d u r e s in 117 of all 501 survivors, 23.4%), than in the TEA g r o u p (50 p r o c e d u r e s in 35 of all 226 survivors, 15.5%). The indications for these operations are listed in Table 6. Re-operations for aorto-iliac or infrainguinal (re-)obstruction were only carried out if critical ischaemia was present, or if justified b y disabling claudicat~on. False a n e u r y s m s only d e v e l o p e d in patients with a vascular prosthesis, w h e t h e r inserted in the first instance or as a secondary p r o c e d u r e following an initial TEA. 2s The same holds true for prosthetic infections, w h i c h were observed in 10 patients (1.9% of all survivors in the PRS group). In six of these patients a re-operation was performed, with operative mortality in four of them. The other four patients died before a re-operation could be carried out. The actuarial chance of being subjected to a n y type of late re-operation for survivors of an aorto-iliac reconstruction !s-i~resented in Figure 4. This chance is significantly greater in the PRS g r o u p than in the TEA g r o u p (p = 0.002).
•
60
~
4o o_
i No. en'~ering intervol 20 i 2 2 9 196 ! 518 589
0
5
126 219 I0 Yeors offer opera'tiOn
72 I00
30 25
15
20
Fig. 3. Cumulative patient survival after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; , PRS.
Table 6. Indications for late, additional operations in different subsets of the population
PRS Patients
TEA Procedures
Patients
Procedures
Indication for reoperation
No.
%*
No.
No.
%*
No.
pWalue
Aorto-iliac re-obstruction
66
13.2
82
21
9.3
27
N.s.
Infrainguinal obstruction
25
5.0
31
12
5.3
18
N.S.
False aneurysm
44
8.8
52
5
2.2
5
Prosthetic infection
6
1.2
6
--
--
--
N.S.
Hydronephrosis
1
0.2
1
--
--
--
N.S.
Total
142t
172
38:[:
= 0.001
50
* Percentage of all survivors of the primary reconstruction in this subset requiring at least one secondary procedure for the specific indication. f Twenty-five patients were included twice because they were subjected to re-operations for two different indications. :~Three patients were included twice because they were subject to re-operations for two different indications. Eur J VascSurg Vol 6, January 1992
Prosthetic and Non-prosthetic Aorto-iliac Surgery
59
I00 .2 80
No. enferinginterval 501 522 226 17l
153 I00
62 49
I0 15
g 80 ¸
0
~ 60;
60
&
_o ~ 40~ >1
>,
/
~ 2o
/
~
/r
| No. entering interval 20 i 2 2 6 145 501 290
..... n
i
5
:
;
i
I
I0 Years after operation
I
4oi J
I
15
~
20
Fig. 4. Actuarial incidence of late re-operations for various indications after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; - - - , PRS.
i
I
i
0
I
I
78
55 47
124 i
l
i
J|0
i
I
i
I
5
14 8
~ _
15
20
Years after operation
Fig. 5. Cumulative primary patency after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; - - - , PRS.
I00 ~
..........
Long-term technical and functional results c
8O
The primary patency curves show a re-occlusion rate of about 10.5% per 5 years after operation in the PRS group, and of about 7% in the TEA group (Fig. 5), a statistically significant difference (p = 0.05). Longterm patency was markedly extended by late reoperations. The secondary patency curves (Fig. 6), thus including the effects of these procedures, show eventual re-occlusion rates of about 5% per 5 years in the PRS group, and of about 3.5% in the TEA group, a statistically insignificant difference (p = 0.07). A question of critical importance from the patient's point of view is his chance of actually benefiting from the surgical procedure at any time period after operation. In order to clarify this question, the curves expressing functional success are presented in Figure 7. There was no statistically significant difference, since the functional failure rate was about 7% per 5 years after operation in both groups. During the years of long-term follow-up, a major amputation had to be performed in 23 cases in the PRS group (4.6% of all survivors in this group). In 17 cases (3.4%) this was due to aorto41iac re-obstruction and in six cases (1.2%) to progressions of femoropopliteal disease. In the TEA group six amputations (2.6%) had to be performed, of which three (1.3%) were' due to aorto-iliac re-obstruction and three (1.3%) to femoro-popliteal obstruction.
Long-term results in the TEA-lira and TEA-ext subsets In addition to the one operative death in the TEA-lim subset and two operative deaths in the TEA-ext subset, 26 patients (28.0%) in the TEA-lira subset and 68
>,
6O
40
~_
No. entering interval 20 ~ 226 155 501 516 I
0
i
i
I
I
5
91 153 i
I
I
jOI
43 66 I
I
I
~
iS1
18 15 I
I
2kO
Years after operation
Fig. 6. Cumulative secondary patency, thus including the effects of all late re-operations, after aorto-iliac reconstruction for obstructive disease in the two groups, according to the type of operation. - - - , TEA; , PRS.
I00 8O
-~ ~-
60
i
[
"~
40
R
20
o
No. en#ering interval 226 175 501 539
g
108 172 i
i
i
:
59 78 i
~ 1
I0 Years after operation
,
25 24 I
!
i
20
15
Fig. 7. Cumulative functional success in the two groups, according to the type of operation. - - - , TEA; , PRS.
patients (50.0%) ot the TEA-ext subset died during the period under study. The cumulative survival curves for both subsets are presented in Figure 8, showing a highly significant difference in favour of the TEA-lim subset (p = 0.003). Eur J Vasc Surg Vol 6, January 1992
60
P.J. van den Akker etal.
,ooF
_
ischaemic symptoms, and specific cardiovascular and other risk factors were significantly more common in the PRS subset than in the TEA subset. Such characteristics should be regarded as specific expressions of different patterns of arteriosclerotic disease 1"17,26 and imply different risks for all possible future manifestations of this systemic disease. Second, PRS and x:l TEA cannot be regarded as two exchangeable modali~- 20 t No~entering interval ties of treatment. To a great extent, TEA was restric83 51 29 16 /136 ,13 75 43 14 ted to the patients with localised disease, and only /. I I i ] i i i ~ I i i i i I carried out if technically feasible. Consequently, o 5 Io 15 20 patient and treatment selection are an obvious explaYeors offer operofion Fig. 8. Cumulative patient survival after aorto-iliac endarterec- nation for the differences in outcome of the present tomy in two subsets of the thromboendarterectomy-group,accord- analysis. ing to the extension of obstructive disease. ---, TEA-ext; - - , Since such selections have always hampered a TEA-lim. sound comparison of the two operative approaches, 27 considerations other than results of comparative Late, additional operations were necessary in studies serve the purpose of choosing between TEA nine patients of the TEA-Iim subset (i.e. 9.8% of all and PRS. For example, the technical problems of TEA survivors in this subset), and in 26 patients (19.4%) of and the chances of recurrence and progression of disthe TEA-ext subset. The actuarial chance of such pro- ease in the aorto-iliac vessels have been well docucedures was significantly smaller in the TEA-lim mented by many authors 1' 6-11 and have caused many than in the TEA-ext subset (p < 0.001). surgeons to abandon its use. On the other hand, Late aorto-iliac re-obstruction was observed in excellent results of TEA have been reported not five patients (5.4%) in the TEA-lim subset, in all only in the present study but also in many other cases more than 9 years after the primary procedure. studies.l-B, lo,~s, 16 Moreover, notwithstanding the Patency was restored by re-operation in four cases, good results of prosthetic reconstruction, 2-5 the which left only one case with late aorto-iliac re- specific risks of prosthetic implants, such as the obstruction in this subset. In the TEA-ext subset late occurrence of prosthetic infections and the developaorto-iliac re-obstruction occurred in 25 patients ment of false aneurysms 25"28 must be recognised. (18.7%), and re-operations for this indication were These considerations have been the reason over the carried out in 17 cases. These results were associated years for maintaining our strategy of preferentially with significantly better long-term cumulative performing a TEA in patients with localised obstrucpatency curves for the TEA-Iim than for the TEA-ext tive disease, rather than inserting a prosthesis in such subset, both for primary (p < 0.001) and for second- cases. ary patency (p < 0.002). The results of this study contradict the fear that Late functional failure was observed in the TEA- late, additional operations are needed after TEA. We lim subset in six patients (6.5%), in the earliest case 8 found that immediate reinterventions as well as late, years after the primary procedure, and in the TEA- additional operations were more often carried out in ext subset in 20 patients (14.9%), in addition to the six the PRS group than in the TEA group. Survival early functional failures (4.5%). The cumulative func- curves as well as primary and secondary patency tional success curve was significantly better for the curves were better in the TEA group than in the PRS TEA-Iim than for the TEA-ext subset (p < 0.001). group. However, functional results were similar for both groups, which is explained by the equalising effects of collateral bloodflow and of concomitant femoro-popliteal obstructive disease. 29 The positive Discussion effects of patient selection were most prominent when regarding the results in the subset of patients The results as found in this study, should not be within the TEA group with strictly localised obstrucinterpreted as indicating the superiority of TEA over tive disease. The superiority of the results in the PRS as surgical treatment for aorto-iliac obstructive TEA-lim subset over those in the TEA-ext subset disease for two reasons. First, TEA and PRS were was demonstrated by significantly better survival carried out in groups of patients with different char- curves, patency curves, functional success curves, acteristics, since extensive obstructive lesions, severe and the lesser need for late, additional surgery. Eur J VascSurgVol6, January1992
Prosthetic and Non-prosthetic Aorto-iliac Surgery
These considerations indicate that TEA is assodated with excellent results in properly selected patients. The very fact that proper selection, as such, must be interpreted as a factor of importance, also implies that the comparison with PRS is inappropriate. We therefore cannot claim that similar or even better results could have been obtained in these patients with PRS instead of TEA. Thus, we have presented our results of PRS not to serve as a comparison with TEA, but rather to illustrate the relevant background of the overall consequences of our approach to reconstructive surgery for AIOD. We believe that the outcome of our study justifies our strategy of choosing TEA rather than PRS for the treatment of AIOD confined to the aorta and common lilac arteries in selected patients. Finally, the place of PTA for this selected group of patients must be addressed. Short common iliac artery stenoses have been reported to respond well to PTA.12-14 The dilatation of this type of stenosis is associated with a low complication rate and initial technical and functional success rates of about 95%. Long-term patency, however, was found to be only 63% at 5 years in a prospective study of patients with optimal characteristics, i.e. intermittent claudication, common iliac stenoses, and good run-off. Results were markedly worse in cases with critical ischaemia, sites other than the common iliac artery, occlusion instead of stenosis and poor run-off. 12 In selected patients, suitable for PTA and TEA, these factors should be included before a decision about treatment is made.
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61
8 BUCKBERGGD, HENNEYRP, CANNONJA. Postoperative complications of aortoiliac endarterectomy: incidence, cause, and prevention. Surgery 1968; 63: 121-127. 9 PEROUEGD, LONGWD, SMITHRB. Perspective concerningaortofemoral arterial reconstruction. Ann Surg 1971; 173: 940-944. 10 INAHARA T. Evaluation of endarterectomy for aortoiliac and aortoiliofemoral occlusive disease. Arch Surg 1975; 110: 1458-1464. 11 CRAWFOROES, MANNING, LG, KELLYTF. "Redo" surgery after operations for aneurysm and occlusion of the abdominal aorta. Surgery 1977; 81: 41-52. 12 JOHNSTON KW, RAE M, HOGG-JOHNSTONSA, et al. Five-year results of a prospective study of percutaneous transluminal angioplasty. Ann Surg 1987; 206: 403-413. 13 RUTHERFORDRB, PATTA, KUMPEDA. The current role of percutaneous transluminal angioplasty. In: GREENHALGHRM, JAMIESON CW, NICOLAIDESAN, eds. Vascularsurgery: Issues in Current Practice. London: Grune & Stratton, 1986; 229-244. 14 TEGTMEYER CJ, HARTWELL GD, BAYNE SELBY J, ROBERTSON R, KRON IL, TRIBBLECG. Results and complications of angioplasty in aortoiliac disease. Circulation 1991; 83 suppl. I: 53-60. 15 STAPLE TW. The solitary aortoiliac lesion. Surgery 1968; 64: 569-576. 16 WYLIEEJ, OLCOTTC, STRINGST. Aortoiliac thromboendarterectomy. In: VARCO RL, DELANEYJP, eds. Controversy in Surgery. Philadelphia: WB Saunders, 1976; 437-450. 17 DEBAKEYME, LAWRIEGM, GLAESERDH. Patterns of atherosclerosis and their surgical significance. Ann Surg 1985; 201: 115-131. 18 SATIANIB, LIAPISCD, HAYESJP, KIMMINSS, EVANSWE. Prospective randomized study of concomitant lumbar sympathectomy with aortoiliac reconstruction. Am J Surg 1982; 143: 755-760. 19 CAMPBELL WB. Surgical and chemical sympathectomy. In: GREENHALGHRIVI, ed. Indications in Vascular Surgery. Philadelphia: WB Saunders, 1988; 401-418. 20 VAN BOCKELJH, VAN SCHILFGAARDER, FELTHUISW, HERMANSJ, TERPSTRAJL. Influence of preoperative risk factors and the surgical procedure on surgical mortality in renovascular hypertension. Am J Surg 1988; 155: 770-775. 21 VAN DERMEERFJM, GERRITS-DRABBECW. Therapeutic control of oral anticoagulant treatment in the Netherlands. Am J Clin Pathol 1988; 90: 685-690. 22 VAN DEN AKKERPJ, VANHOCKErJH, BRANDR, VANSCHILEGAARDE R. Computerised vascular data management. A flexible modular registry suitable for the evaluation of long-term results in patients subjected to multiple interventions. Eur J Vasc Surg 1991; 5: 459-465. 23 CUTLER, SJ, EDERER F. Maximum utilization of the life table method in analyzing survival, l Chron Dis 1958; 8: 699-712. 24 STOKESJM, SuGG WL, BUTCHERHR. Standard method of assessing relative effectiveness of therapies for arterial occlusive disease. Ann Surg 1963; 157: 343-350. 25 VAN DEN AKKERPJ, VAN SCHILFGAARDER, BRANDR, VAN BOCKEL JH, TERPSTRAJL. False aneurysms after prosthetic reconstructions for aortoiliac obstructive disease. Ann Surg 1989; 210: 658-666. 26 BREWSTERDC. Clinical and anatomical considerations for surgery in aortoiliac disease and results of surgical treatment, Circulation 1991; 83 (Suppl I): 42-52. 27 NICOLAIOESAN, GRIGGJM. Are there any indications for aortic and iliac endarterectomy? In: GREENHALGHRM, ed. Indications in Vascular Surgery. Philadelphia: WB Saunders, 1988; 201-213. 28 SZILAGYIDE, SMITH RE, ELLIOTTJP, HAGEMANJH, DALL'OLMo CA. Anastomotic aneurysms after vascular reconstruction: problems of incidence, etiology, and treatment. Surgery 1975; 78: 800-816. 29 VAN DEN AKKERPJ, VAN SCHILFGAARDER, BRANDR, VAN BOCKEL JH, TERPSTRAJL. Long-term success of aortoiliac surgery for arteriosclerotic obstructive disease. Surg Gynecol Obstet 1991; in press.
Accepted 8 October 1991
Eur J Vasc Surg Vol 6, January 1992