- Email: [email protected]
Can the retroperitoneal approach be used for ruptured abdominal aortic aneurysms?
Can the retropcritoncal approach be used for ruptured abdominal aortic ancurysms? Benjamin B. Chang, MD, Dhiraj M. Shah, MD, Philip S. K. Paty, MD, Jeffrey L. Kaufman, MD, and Robert P. Leather, MD, Albany, N.Y. The retroperitoneal approach for elective treatment of abdominal arotic aneurysms is an accepted alternative to midline transperitoneal approaches and may provide less physiologic insult and a smoother postoperative course. In recent years we have preferentially used the extended retroperitoneal approach for ruptured abdominal aortic aneurysms to derive similar physiologic benefits for these patients. Over a 6-year period (1983 to 1989) 76 cases of ruptured abdominal aortic aneurysms were treated by emergency aortic replacement. After exclusion of 13 patients whose aneurysmal ruptures were unusual, such as aortoenteric fistula, aortocaval fistula, chronic contained rupture, or visceral involvement, 63 patients were retrospectively studied. Thirty-eight patients were treated via a standard transperitoneal celiotomy and 25 via a left retroperitoneal incision. No significant differences were found between the two groups in regard to cardiac or pulmonary fimction or duration of preoperative hypotension. Operative mortality was lower in the retroperitoneal group (three of 25, 12%) as compared to the transperitoneal group (13 of 38, 34.2%). Furthermore, the retroperitoneal group required less ventilatory support and tolerated enteral feedings quickly. Length of stay in the hospital was also significantly reduced in the retroperiteonal group. These data indicate that maaly ruptured abdominal aortic aneurysms can be successfitUy treated through the left retroperitoneal approach. In this nonrandomized clinical series increased survival rates and shorter periods of postoperative recovery were noted in the patients operated with the retroperitoneal approach. (J Vasc Suv,a 1990;11:326-30.)
The surgical treatment of ruptured abdominal aortic aneurysms has not been cntirely satisfactory in the face of several decades of accumulated surgical experience. In spite of the myriad improvements in preoperative evaluation, anesthetic management, and postoperative care that have been responsible in part for the improvement of elective surgical results, operative treatment of the ruptured aneurysm still typically results in a mortality rate of 30% to 70%. 1-6 This alternative approach to the ruptured aortic aneurysm was developed in hopes of improving patient survival and applying experience gained with the use of the extended retroperitoneal approach for elective surgery of the abdominal aorta. 7 This nonrandomized clinical series compares the results of the retroperitoneal approach with that of a conventional midline laparotomy for ruptured abdominal aortic aneurysm over a 6-year period. From the Department of Surgery, Albany Medical College. Presented at the Thirty-third Annual Meeting of The Society for Vascular Surgery, New York, N.Y., June 20-21, 1989. Reprint requests: Dhiraj M. Shah, MD, Department of Surgery (A61), Albany Medical College, Albany, NY 12208. 24/6/17036
326
MATERIAL AND METHODS Thc operative approach has been previously described. 7 However, the initial incision is now made in the tenth interspace, above the eleventh rib, from the posterior axillary line to the lateral margin of the ipsilateral rectus abdominus. The remainder of the technique, involving compression and subsequent clamping of the supraceliac aorta before exposure of the aorta and surrounding hematoma, remains similar. All patients also received intravenous mannitol (25 gram bolus followed by 5 gm/hr continuous infusion for a minimum of 8 hours). Swan Ganz catheters were also routinely used during and after the operation. All patients with the diagnosis of ruptured abdominal aortic aneurysm were operated on. Patients with asystole and/or undergoing cardiopulmonary resuscitation were not excluded from operation. Statistical analysis was performed with the BMDP statistical software package. Tests used included Student's t test for data conforming to a normal distribution, the Mann-Whitney test for data not conforming to a normal distribution, and chi-square analysis.
Volume 11 Number 2 Februa~ 1990
RESULTS
Seventy-six patients with ruptured abdominal aortic aneurysm were treated at our two hospitals from 1983 to 1989. Thirteen patients had unusual forms of ruptured aneurysm and were therefore excluded from further analysis. Reasons for exclusion included primary aortoenteric fistula (one patient, transperitoneal), aortocaval fistula (two, transperitoneal), ruptured iliac aneurysm (three, one retroperitoneal, two transperitoneal), infected aneurysm (two, retroperitoneal and transperitoneal), chronic contained rupture (two retroperitoneal), and ruptured visceral aortic aneurysm (three, retroperitoneal and transthoracic). These patients were treated by transperitoneal, retroperitoneal, and combined approach. Twenty-five of the remaining patients underwent aneurysm repair via the retroperitoneal approach whereas the remaining 38 underwent repair via the transperitoneal approach. Table I details the demographic data of these two groups; no major differences existed. Tables II and III detail various preoperative and intraoperative parameters. It should be noted that a relatively high percentage of these patients were hypotensive before surgery. Total operative time was significantly longer in the retroperitoneal group. However, aortic cross-clamp time was not significantly different. Conversely, patients in the transperitoneal group had a significantly increased duration of intraoperative hypotension (systolic blood pressure less than 90 mm Hg). Otherwise, no significant differences in blood loss or fluid requirements occurred between the two groups. There was no difference in anatomic or pathologic characteristics for aneurysms between the two groups. In the initial two to three patients, left retroperitoneal approach was avoided when the hematoma was found to be on the left side by CT scanning but in recent years all patients, irrespective of the site of rupture, were treated by left retroperitoneal approach. The effect of differences in operative technique on postoperative recovery in survivors can be seen in Table IV. Patients in the retroperitoneal group had significantly decreased hospital stays. In addition, the retroperitoneal group was able to tolerate enteral feeding significantly faster. Mortality was significantly less in the retroperitoneal group (3/25, 12%) as compared to the transperitoneal group (13/38, 34.2%, X2 = 4.59, p < 0.05). Interestingly, there were no intraoperative deaths in the retroperitoneal group as compared to three in the transperitoneal group, all from cardiac
Retroperitoneal approachfor ruptured aneurysms 3 2 7
Table I. Demographics and risk factors Retroperitoneal No. o f patients Age (yr) ~ Cardiac disease (n) Hypertension (n) Pulmonary (n)
25 70 -+ 2
Transperitoneal 38 72 _+ 8
7
9
7
15
5
8
~Values are expressed as mean +_ SEM.
arrest brought on by hypotension. The remainder of deaths in both groups were due to myocardial infarction (four), sepsis (two), and multiple organ system failure (seven). Three patients had ischemic olitis, two in the transperitoneal group and one in the retroperitoneal group. During the initial 12 years of this report, transperitoneal approach was used exclusively, during the midperiod both approaches were used, and in recent years the transperitoncal approach has been largely discarded except in cases where the diagnosis was equivocal and thought to be other than ruptured aneurysm. In the past 18 months, there have been only two ruptured aneurysms treated by a transperitoneal approach. DISCUSSION The results of the treatment of ruptured abdominal aortic aneurysms have not reflected the improvements seen in virtually all other aspects of vascular surgery. Despite several decades of experience with the transperitoneal approach, there has been little improvement in mortality rates in most of the reported series, 1,2 with few exceptions. 8 The reasons for this continued high mortality rate are probably multifactorial. Because these cases are often performed in smaller hospitals with limited resources and by surgeons with limited experience, the use of triage and transport has been shown to be a beneficial and effective method of centralizing these cases to larger, more experienced facilities, s,9 Howevcr, the common use of antishock trousers probably has little to recommend itself and is related to high complication rates in these patients with diseased, atherosclerotic arteries) ° Preoperative evaluation has remained substantially unchanged; although CT scanning is often useful in demonstrating rupture in stable patients, a rapid trip to the oper~xing room is still the hallmark of good surgical management. Intraoperative anesthetic management has undergone a progressive evolution at our institutions.
328
~ottrnal of VASCULAR SURGERY
Chang et al.
T a b l e I I . Preoperative and intraoperative parameters Retroperitoneal
No. of patients No. of patients with preoperative hypotension In-hospital preoperative delay (min)~ Aortic cross-damp time (min)~ Operative time (min)~ Intraoperative hypotension (min)~
25 16 66 -+ 19 114 + 10 279 +- 13 4 _+ i
Tansperitonea!
48 100 210 15
38 24 + 9 -+ 6 _+ 13 + 3
Statistical anMysis ~ ~ NS NS NS p < 0.0I p < 0.01
~Values are expressedas mean _+ SEM. ~Student t test and Mann-Whitney test.
Table I I I . Intraoperative fluid requirements
Crystalloid infused (ml)~ Blood transfused (ml)~ Intraoperative blood loss (ml)~
Retroperitoneal
Transperitoneal
Statistical analysis ~ ~
5776 -+ 456 2217 + 292 3515 -+ 581
6419 _+ 420 2811 _+ 278 4284 -+ 418
NS NS NS
~Values are expressedas mean _+ SEM. *~Student t test and Mann-Whimey test.
Table IV. Parameters o f postoperative recovery in survivors Retroperitoneal
No. of patients Postoperative hospitalization (days)~ Intensive care stay (days)* Endotracheal intubation (days)~ Initiation of alimentation (days)~
22 9 7 8
22 _+ 5 -+ 4 _+ 3 + 2
Transperitoneal
40 14 12 11
25 _+ 10 _+ 4 -+ 4 _+ 2
Statistical analysis ~ *
-p < 0.05 NS NS p < 0.05
~Values are expressedas mean _+ SEM. ~*Student t test and Mann-Whitney test.
The use o f high doses o f fentanyl and morphine anesthesia when possible, intraoperative monitoring o f cardiovascular status with Swan-Ganz catheters, and an improved understanding o f the need for correction o f hypothermia and coagulation defects have each led to significant improvements in intraoperative management. However, these improvements were used during the entire course o f this entire series and could not be responsible for the differences between the two study groups. The transperitoneal operative approach for ruptured abdominal aortic aneurysms has not changed appreciably for several years. Gaining rapid, reliable control o f the neck o f the aneurysm without causing major venous or arterial injury is often difficult because o f p o o r exposure and continued hemorrhage. Initial clamping o f the supraceliac aorta through the lesser sac has been advocated as a means o f saving time and controlling hemorrhage; this method was used in most o f the transperitoneal group in this series.
The retroperitoneal approach for elective aneurysm surgery has been reported to be associated, in general, with a decreased physiologic insult and more rapid recovery. ~1"13 This has become our preferred method o f elective aneurysm repair. Application o f this experience to the treatment o f ruptured aneurysms is a natural extension o f this technique. By use o f the extended retroperitoneal approach as reported by Williams, 14 the entire infradiaphragmatic aorta may be easily exposed. This is especially important in treating patients with ruptured aneurysms as this allows for manual and clamp control o f the supraceliac aorta before exposure o f the aneurysm proper through the hematoma. It should also be pointed out that other versions o f the retroperitoneal approach such as the anterolateral approach reported by R o b is and Sicard et al. 13 are probably unsuitable for treatment o f most ruptured aneurysms as they do not provide such ready access to the supraceliac aorta. The direct exposure o f the neck o f the aneurysm, which is necessary in these methods before proximal
Volume11 Number2 February1990
control is obtained, would require exposure o f the aneurysm and decompression o f the contained hematoma with massive hemorrhage in many cases. Furthermore, a more anterior retroperitoneal aortic exposure usually requires separation o f the left kidney from the peritoneum; this would be hazardous in the setting o f a ruptured aneurysm. We would emphasize that with the posterolateral retroperitoneal approach advocated in this report, control o f the aorta can be achieved quickly, safely, and reliably in all cases. In very obese patients or in those persons with multiple previous celiotomies and adhesion formation, secure control o f the aorta can be gained from this retroperitoneal approach. In this group o f patients, traditional midline exposure may be especially troublesome and require prolonged periods o f dissection before cross-clamping. The three intraoperative deaths in the transperitoneal group in this series were all related to delayed cross-clamping as a result o f previous adhesions. The left rctroperitoneal approach for ruptured aneurysm may bc contraindicated in patients undergoing active external cardiac massage for resuscitation and in patients with a questionable diagnosis. Furthermore, the surgeon must have experience with this approach for repair o f elective aneurysms before using this approach for ruptured aneurysms. The decreased mortality seen in the retroperitoheal group is most likely related to the approach itself, as there were few other differences between the two groups. The salutary effects o f the retroperitoneal approach in the elective setting have been retrospectively studied; whether the physiologic reasons for this are related to differences in vasoactive chemical secretion ~6or other unidentified factors is not known. Nevertheless, if would appear logical that if these effects were present in the elective situation then they may also pertain in the emergency setting. This explanation is supported by the shorter hospital stay and more expedient return o f gastrointestinal function in the retroperitoneal group. This latter effect may also be related to decreased manipulation o f the bowel in the retroperitoneal group. Furthermore, there was a trend toward decreased length o f intubation that might well become significant when greater numbers o f patients are studied. The only caveat to the use o f this approach is that performing the maneuvers necessary for supraceliac control via the retroperitoneal approach is best practiced in the elective setting as the initial exposure is limited and must be performed by a single operator. Therefore, surgeons who are already familiar with the extended retroperitoneal approach may easily ap-
Retroperitonealapproachfor ruptured aneurysms 329
ply this to the emergent case. However, surgeons who do not electively use the retroperitoneal approach will likely find this method difficult at best. In conclusion, the data presented herein demonstrate that the extended retroperitoneal approach may be used in the treatment o f ruptured abdominal aortic aneurysms with excellent results. Furthermore, as compared to the transperitoneal group, the retroperitoneal group had a shorter hospital stay and more rapid recovery o f gastrointestinal function in this nonrandomized clinical series. With experience, this approach should be preferred in patients with ruptured aneurysms who are very obese and/or may have intraabdominal adhesions. REFERENCES
1. ChiarelloL, Reul GJ Jr, Wukasch DC, SandifordFM, Hallman GL, CooleyDA. Ruptured abdominal aortic aneurysm: treatment and review of eighty-sevenpatients. Am I Surg 1974;128:735-8. 2. DiGiovanniR, Nicholas G, Volpetti H. BerkowitzH, Barker C, Roberts B. Twenty-one years' experiencewith ruptured abdominal aortic aneurysms. Surg Gynecol Obstet 1975; 141:859-62. 3. Donaldson MC, Rosenberg JM, Buckman CA. Factors affecting survival after ruptured abdominal aortic aneurysm. J VAse SURG1985;2:564-70. 4. Hoffman M, AvelloneJC, Plecha FR, et al. Operation for ruptured abdominal aortic aneurysm: a community-wideexperience. Surgery 1982;91:597-602. 5. Pilcher DB, Davis JH, Askikaga T, et al. Treatment of abdominal ao~ic aneurysmin an cntire state over 7 1/2 years. Am J Surg 1980;139:487-94. 6. WakefieldTW, Whitehouse WM, Wu S, et al. Abdominal aortic aneurysmrupture: statisticalanalysisof factorsaffecting outcome of surgical treatment. Surgery 1982;91:586-96. 7. Chang BB, Paty PK, Shah DM, Leather PP. Selectiveuse of retroperitonealexposurein the emergencytreatment of ruptured abdominalaorticaneurysms.Am I Surg i988; 156:10810. 8. LawrieGM, Morris GC, CrawfordES, et al. Improvedresults of operation for ruptured abdominal aortic aneurysms. Surgery 1979;85:483~8. 9. Hannan EL~ O'Donnelt IF, Kilburn H. Bernard HR. Investigation of the relationshipbetweenvolumeand mortalityfor surgical proceduresperformed in New York State hospitals. JAMA 1989;262:503-].0. 10. SavinoJA, labbour I, AgarwalN, ByrneD. Overinflationof pneumatic antishock garments in the elderly. Am J Surg I989;155:572-7. 11. Shepard AD, Scott GR, MackeyWC, O'Donnell TF, Bush HL, Callow AD. Retroperitonealapproach to high risk abdominal aortic aneurysms.Arch Surg 1986;I21:444-9. i2. Leather liP, Shah DM, KaufmanJL, FitzgeraldKM, Chang BB, Feustel PJ. Comparativeanalysis of retroperitonealand transperitoneal aortic replacement for aneurysm. Surg Gynecol Obstet I989;168:387-93. 13. Sicard GA, Freeman MB, Vanderwoude JC, Anderson CB. Comparison betweenthe transabdominaland retroperitoneal approachfor reconstructionof the infrarenalabdominalaorta. J VASCSURG1987;5:19-27.
330
Chang et al.
,Xournalof VASCULAR SURGERY
14. Williams GM, Ricotta J, Zinner M, Burdick JF. The extended retroperitoneal approach for treatment of extensive atherosclerosis of the aorta and renal vessels. SurgeD, 1980;88:84655. 15. Rob C. Extraperitoneal approach to the abdominal aorta. Surgery 1963;53:87-9.
16. Gottlieb A, Skrilaska VA, O'Hara P, Boutros AR, Melia M, Beck GI. The role of prostacydin in the mesenteric traction syndrome during anesthesia for abdominal aortic reconstruction surgery. Am J Surg I989;209:363-7.
DISCUSSION Dr. G. Melville Williams (Baltimore, Md.). The authors are certainly to be congratulated for their excellent results in treating this most difficult surgical challenge. We did more suprarenal and visceral aneurysms that were excluded from the present study than we did infrarenal, and the experience is very meager. Our results are better with the suprarenal group than they are the infrarenal group, and this is largely because we chose this approach in the group with the infrarenal aneurysms in patients that we thought this was their only hope of getting them through it. These are their associated diseases: two with terrible valve disease and congestive heart failure, one with a concomitant aortoduodenal fistula, and one that was 3 weeks after resection of a thoracic aneurysm. Thus I am in complete agreement with the authors' conclusion that this approach is optimal in this group of patients who are stable after initial period of rupture. However, I find the period of time taken to position the patient and have the anesthetist quieted intolerable in patients in shock. Thus although demographic statistics such as sex and age and duration of rupture may be similar in both of the groups of patients treated by the extra- and intraperitoneal approach, I wonder if the former do not include more patients requiring intraoperative resuscitation, which is far easier today with patients in the supine position than when they are on their side. Would you agree with us that there are indications for each approach, selecting the midline for patients in shock or in those whose diagnosis may be in doubt, and chosing the extraperitoneal approach for all patients who are stable in the operating room? Dr. Robert P. Leather. We approached this with some trepidation, and actually the first two cases that we did
were ruptured visceral aneurysms. We then began initially with identified right-sided ruptures, and with greater experience we moved to treat all ruptured aortic aneurysms in this fashion, as you saw from the case distribution over the past several years. I would emphasize the point that one should be thoroughly familiar with this approach on an elective basis. In the same period we have done more than 250 retroperitoneal approaches to abdominal aneurysms, so that one must be familiar with this approach. I think for someone who is not familiar and has some hesitancy about it, clearly the transabdominal approach would be in the best interests of the patient and the surgeon for the reasons that Dr. Williams has already outlined. We make no attempt to suggest that use of the retroperitoneal approach is necessarily superior to the transperitoneal approach. However, we were able to achieve a relatively low mortality rate in our series, superior to that of our own results with the transperitoneal approach. The outcome in general is so influenced by factors other than the technical aortic replacement that comparison with other institutions is a problem. However, we do advocate the use of the retroperitoneai approach even in patients in shock, unless they are actively undergoing cardiopulmonary resuscitation at the time. With experience with elective aneurysms, we can position the patient and gain control of the aorta in very short order in all cases. This is especially useful in patients in shock who have had multiple previous celiotomies, as was the case in several patients in this series. This is in part reflected by the fact that in no cases of the retroperitoneal group did death occur because of failure to obtain expedient aortic control, whereas this was clearly not the case in the transperitoneal group.
The surgical treatment of ruptured abdominal aortic aneurysms has not been cntirely satisfactory in the face of several decades of accumulated surgical experience. In spite of the myriad improvements in preoperative evaluation, anesthetic management, and postoperative care that have been responsible in part for the improvement of elective surgical results, operative treatment of the ruptured aneurysm still typically results in a mortality rate of 30% to 70%. 1-6 This alternative approach to the ruptured aortic aneurysm was developed in hopes of improving patient survival and applying experience gained with the use of the extended retroperitoneal approach for elective surgery of the abdominal aorta. 7 This nonrandomized clinical series compares the results of the retroperitoneal approach with that of a conventional midline laparotomy for ruptured abdominal aortic aneurysm over a 6-year period. From the Department of Surgery, Albany Medical College. Presented at the Thirty-third Annual Meeting of The Society for Vascular Surgery, New York, N.Y., June 20-21, 1989. Reprint requests: Dhiraj M. Shah, MD, Department of Surgery (A61), Albany Medical College, Albany, NY 12208. 24/6/17036
326
MATERIAL AND METHODS Thc operative approach has been previously described. 7 However, the initial incision is now made in the tenth interspace, above the eleventh rib, from the posterior axillary line to the lateral margin of the ipsilateral rectus abdominus. The remainder of the technique, involving compression and subsequent clamping of the supraceliac aorta before exposure of the aorta and surrounding hematoma, remains similar. All patients also received intravenous mannitol (25 gram bolus followed by 5 gm/hr continuous infusion for a minimum of 8 hours). Swan Ganz catheters were also routinely used during and after the operation. All patients with the diagnosis of ruptured abdominal aortic aneurysm were operated on. Patients with asystole and/or undergoing cardiopulmonary resuscitation were not excluded from operation. Statistical analysis was performed with the BMDP statistical software package. Tests used included Student's t test for data conforming to a normal distribution, the Mann-Whitney test for data not conforming to a normal distribution, and chi-square analysis.
Volume 11 Number 2 Februa~ 1990
RESULTS
Seventy-six patients with ruptured abdominal aortic aneurysm were treated at our two hospitals from 1983 to 1989. Thirteen patients had unusual forms of ruptured aneurysm and were therefore excluded from further analysis. Reasons for exclusion included primary aortoenteric fistula (one patient, transperitoneal), aortocaval fistula (two, transperitoneal), ruptured iliac aneurysm (three, one retroperitoneal, two transperitoneal), infected aneurysm (two, retroperitoneal and transperitoneal), chronic contained rupture (two retroperitoneal), and ruptured visceral aortic aneurysm (three, retroperitoneal and transthoracic). These patients were treated by transperitoneal, retroperitoneal, and combined approach. Twenty-five of the remaining patients underwent aneurysm repair via the retroperitoneal approach whereas the remaining 38 underwent repair via the transperitoneal approach. Table I details the demographic data of these two groups; no major differences existed. Tables II and III detail various preoperative and intraoperative parameters. It should be noted that a relatively high percentage of these patients were hypotensive before surgery. Total operative time was significantly longer in the retroperitoneal group. However, aortic cross-clamp time was not significantly different. Conversely, patients in the transperitoneal group had a significantly increased duration of intraoperative hypotension (systolic blood pressure less than 90 mm Hg). Otherwise, no significant differences in blood loss or fluid requirements occurred between the two groups. There was no difference in anatomic or pathologic characteristics for aneurysms between the two groups. In the initial two to three patients, left retroperitoneal approach was avoided when the hematoma was found to be on the left side by CT scanning but in recent years all patients, irrespective of the site of rupture, were treated by left retroperitoneal approach. The effect of differences in operative technique on postoperative recovery in survivors can be seen in Table IV. Patients in the retroperitoneal group had significantly decreased hospital stays. In addition, the retroperitoneal group was able to tolerate enteral feeding significantly faster. Mortality was significantly less in the retroperitoneal group (3/25, 12%) as compared to the transperitoneal group (13/38, 34.2%, X2 = 4.59, p < 0.05). Interestingly, there were no intraoperative deaths in the retroperitoneal group as compared to three in the transperitoneal group, all from cardiac
Retroperitoneal approachfor ruptured aneurysms 3 2 7
Table I. Demographics and risk factors Retroperitoneal No. o f patients Age (yr) ~ Cardiac disease (n) Hypertension (n) Pulmonary (n)
25 70 -+ 2
Transperitoneal 38 72 _+ 8
7
9
7
15
5
8
~Values are expressed as mean +_ SEM.
arrest brought on by hypotension. The remainder of deaths in both groups were due to myocardial infarction (four), sepsis (two), and multiple organ system failure (seven). Three patients had ischemic olitis, two in the transperitoneal group and one in the retroperitoneal group. During the initial 12 years of this report, transperitoneal approach was used exclusively, during the midperiod both approaches were used, and in recent years the transperitoncal approach has been largely discarded except in cases where the diagnosis was equivocal and thought to be other than ruptured aneurysm. In the past 18 months, there have been only two ruptured aneurysms treated by a transperitoneal approach. DISCUSSION The results of the treatment of ruptured abdominal aortic aneurysms have not reflected the improvements seen in virtually all other aspects of vascular surgery. Despite several decades of experience with the transperitoneal approach, there has been little improvement in mortality rates in most of the reported series, 1,2 with few exceptions. 8 The reasons for this continued high mortality rate are probably multifactorial. Because these cases are often performed in smaller hospitals with limited resources and by surgeons with limited experience, the use of triage and transport has been shown to be a beneficial and effective method of centralizing these cases to larger, more experienced facilities, s,9 Howevcr, the common use of antishock trousers probably has little to recommend itself and is related to high complication rates in these patients with diseased, atherosclerotic arteries) ° Preoperative evaluation has remained substantially unchanged; although CT scanning is often useful in demonstrating rupture in stable patients, a rapid trip to the oper~xing room is still the hallmark of good surgical management. Intraoperative anesthetic management has undergone a progressive evolution at our institutions.
328
~ottrnal of VASCULAR SURGERY
Chang et al.
T a b l e I I . Preoperative and intraoperative parameters Retroperitoneal
No. of patients No. of patients with preoperative hypotension In-hospital preoperative delay (min)~ Aortic cross-damp time (min)~ Operative time (min)~ Intraoperative hypotension (min)~
25 16 66 -+ 19 114 + 10 279 +- 13 4 _+ i
Tansperitonea!
48 100 210 15
38 24 + 9 -+ 6 _+ 13 + 3
Statistical anMysis ~ ~ NS NS NS p < 0.0I p < 0.01
~Values are expressedas mean _+ SEM. ~Student t test and Mann-Whitney test.
Table I I I . Intraoperative fluid requirements
Crystalloid infused (ml)~ Blood transfused (ml)~ Intraoperative blood loss (ml)~
Retroperitoneal
Transperitoneal
Statistical analysis ~ ~
5776 -+ 456 2217 + 292 3515 -+ 581
6419 _+ 420 2811 _+ 278 4284 -+ 418
NS NS NS
~Values are expressedas mean _+ SEM. *~Student t test and Mann-Whimey test.
Table IV. Parameters o f postoperative recovery in survivors Retroperitoneal
No. of patients Postoperative hospitalization (days)~ Intensive care stay (days)* Endotracheal intubation (days)~ Initiation of alimentation (days)~
22 9 7 8
22 _+ 5 -+ 4 _+ 3 + 2
Transperitoneal
40 14 12 11
25 _+ 10 _+ 4 -+ 4 _+ 2
Statistical analysis ~ *
-p < 0.05 NS NS p < 0.05
~Values are expressedas mean _+ SEM. ~*Student t test and Mann-Whitney test.
The use o f high doses o f fentanyl and morphine anesthesia when possible, intraoperative monitoring o f cardiovascular status with Swan-Ganz catheters, and an improved understanding o f the need for correction o f hypothermia and coagulation defects have each led to significant improvements in intraoperative management. However, these improvements were used during the entire course o f this entire series and could not be responsible for the differences between the two study groups. The transperitoneal operative approach for ruptured abdominal aortic aneurysms has not changed appreciably for several years. Gaining rapid, reliable control o f the neck o f the aneurysm without causing major venous or arterial injury is often difficult because o f p o o r exposure and continued hemorrhage. Initial clamping o f the supraceliac aorta through the lesser sac has been advocated as a means o f saving time and controlling hemorrhage; this method was used in most o f the transperitoneal group in this series.
The retroperitoneal approach for elective aneurysm surgery has been reported to be associated, in general, with a decreased physiologic insult and more rapid recovery. ~1"13 This has become our preferred method o f elective aneurysm repair. Application o f this experience to the treatment o f ruptured aneurysms is a natural extension o f this technique. By use o f the extended retroperitoneal approach as reported by Williams, 14 the entire infradiaphragmatic aorta may be easily exposed. This is especially important in treating patients with ruptured aneurysms as this allows for manual and clamp control o f the supraceliac aorta before exposure o f the aneurysm proper through the hematoma. It should also be pointed out that other versions o f the retroperitoneal approach such as the anterolateral approach reported by R o b is and Sicard et al. 13 are probably unsuitable for treatment o f most ruptured aneurysms as they do not provide such ready access to the supraceliac aorta. The direct exposure o f the neck o f the aneurysm, which is necessary in these methods before proximal
Volume11 Number2 February1990
control is obtained, would require exposure o f the aneurysm and decompression o f the contained hematoma with massive hemorrhage in many cases. Furthermore, a more anterior retroperitoneal aortic exposure usually requires separation o f the left kidney from the peritoneum; this would be hazardous in the setting o f a ruptured aneurysm. We would emphasize that with the posterolateral retroperitoneal approach advocated in this report, control o f the aorta can be achieved quickly, safely, and reliably in all cases. In very obese patients or in those persons with multiple previous celiotomies and adhesion formation, secure control o f the aorta can be gained from this retroperitoneal approach. In this group o f patients, traditional midline exposure may be especially troublesome and require prolonged periods o f dissection before cross-clamping. The three intraoperative deaths in the transperitoneal group in this series were all related to delayed cross-clamping as a result o f previous adhesions. The left rctroperitoneal approach for ruptured aneurysm may bc contraindicated in patients undergoing active external cardiac massage for resuscitation and in patients with a questionable diagnosis. Furthermore, the surgeon must have experience with this approach for repair o f elective aneurysms before using this approach for ruptured aneurysms. The decreased mortality seen in the retroperitoheal group is most likely related to the approach itself, as there were few other differences between the two groups. The salutary effects o f the retroperitoneal approach in the elective setting have been retrospectively studied; whether the physiologic reasons for this are related to differences in vasoactive chemical secretion ~6or other unidentified factors is not known. Nevertheless, if would appear logical that if these effects were present in the elective situation then they may also pertain in the emergency setting. This explanation is supported by the shorter hospital stay and more expedient return o f gastrointestinal function in the retroperitoneal group. This latter effect may also be related to decreased manipulation o f the bowel in the retroperitoneal group. Furthermore, there was a trend toward decreased length o f intubation that might well become significant when greater numbers o f patients are studied. The only caveat to the use o f this approach is that performing the maneuvers necessary for supraceliac control via the retroperitoneal approach is best practiced in the elective setting as the initial exposure is limited and must be performed by a single operator. Therefore, surgeons who are already familiar with the extended retroperitoneal approach may easily ap-
Retroperitonealapproachfor ruptured aneurysms 329
ply this to the emergent case. However, surgeons who do not electively use the retroperitoneal approach will likely find this method difficult at best. In conclusion, the data presented herein demonstrate that the extended retroperitoneal approach may be used in the treatment o f ruptured abdominal aortic aneurysms with excellent results. Furthermore, as compared to the transperitoneal group, the retroperitoneal group had a shorter hospital stay and more rapid recovery o f gastrointestinal function in this nonrandomized clinical series. With experience, this approach should be preferred in patients with ruptured aneurysms who are very obese and/or may have intraabdominal adhesions. REFERENCES
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DISCUSSION Dr. G. Melville Williams (Baltimore, Md.). The authors are certainly to be congratulated for their excellent results in treating this most difficult surgical challenge. We did more suprarenal and visceral aneurysms that were excluded from the present study than we did infrarenal, and the experience is very meager. Our results are better with the suprarenal group than they are the infrarenal group, and this is largely because we chose this approach in the group with the infrarenal aneurysms in patients that we thought this was their only hope of getting them through it. These are their associated diseases: two with terrible valve disease and congestive heart failure, one with a concomitant aortoduodenal fistula, and one that was 3 weeks after resection of a thoracic aneurysm. Thus I am in complete agreement with the authors' conclusion that this approach is optimal in this group of patients who are stable after initial period of rupture. However, I find the period of time taken to position the patient and have the anesthetist quieted intolerable in patients in shock. Thus although demographic statistics such as sex and age and duration of rupture may be similar in both of the groups of patients treated by the extra- and intraperitoneal approach, I wonder if the former do not include more patients requiring intraoperative resuscitation, which is far easier today with patients in the supine position than when they are on their side. Would you agree with us that there are indications for each approach, selecting the midline for patients in shock or in those whose diagnosis may be in doubt, and chosing the extraperitoneal approach for all patients who are stable in the operating room? Dr. Robert P. Leather. We approached this with some trepidation, and actually the first two cases that we did
were ruptured visceral aneurysms. We then began initially with identified right-sided ruptures, and with greater experience we moved to treat all ruptured aortic aneurysms in this fashion, as you saw from the case distribution over the past several years. I would emphasize the point that one should be thoroughly familiar with this approach on an elective basis. In the same period we have done more than 250 retroperitoneal approaches to abdominal aneurysms, so that one must be familiar with this approach. I think for someone who is not familiar and has some hesitancy about it, clearly the transabdominal approach would be in the best interests of the patient and the surgeon for the reasons that Dr. Williams has already outlined. We make no attempt to suggest that use of the retroperitoneal approach is necessarily superior to the transperitoneal approach. However, we were able to achieve a relatively low mortality rate in our series, superior to that of our own results with the transperitoneal approach. The outcome in general is so influenced by factors other than the technical aortic replacement that comparison with other institutions is a problem. However, we do advocate the use of the retroperitoneai approach even in patients in shock, unless they are actively undergoing cardiopulmonary resuscitation at the time. With experience with elective aneurysms, we can position the patient and gain control of the aorta in very short order in all cases. This is especially useful in patients in shock who have had multiple previous celiotomies, as was the case in several patients in this series. This is in part reflected by the fact that in no cases of the retroperitoneal group did death occur because of failure to obtain expedient aortic control, whereas this was clearly not the case in the transperitoneal group.