Predictors of Early Discharge following Open Abdominal Aortic Aneurysm Repair

Predictors of Early Discharge following Open Abdominal Aortic Aneurysm Repair Apostolos K. Tassiopoulos, MD,1,2 Sung S. Kwon, MD,1 Nicos Labropoulos, PhD,1 Tanuja Damani, MD,1 Fred N. Littooy, MD,1 M. Ashraf Mansour, MD,1 Steven S. Kang, MD,1 and William H. Baker, MD,1 Maywood and Chicago, Illinois

Patients undergoing endovascular abdominal aortic aneurysm (AAA) repair have lower perioperative morbidity and leave the hospital earlier than patients undergoing open repair. However, potential complications require continuous surveillance of endografts and there are few data regarding their long-term fate. If an open operation were well tolerated, this might be a preferable alternative. The purpose of this study was to identify patients with lower morbidity and shorter hospital stay following open AAA repair and to analyze factors that might point to open repair as the preferred approach. We performed a retrospective review of all patients who underwent AAA repair between 1995 and 2000 at our institution. All patients with ruptured aneurysms and those that required renal, celiac, or superior mesenteric reconstructions during the AAA repair were excluded. Patient demographics, preoperative comorbid conditions, intraoperative data, and postoperative complications were analyzed in detail. A total of 115 patients fulfilled the inclusion criteria. There was only one perioperative death (0.9%). The mean hospital stay was 8.1 days. A history of chronic obstructive pulmonary disease (COPD) and longer operative time were independent factors associated with prolonged hospital stay. Forty-one patients (35.6%) left the hospital in 5 or less days. Compared to the group with hospital stay >5 days, these patients had a lower incidence of COPD (7.3% vs. 25.7%, p < 0.05) and smaller-size AAAs (5.6 vs. 6.4 cm, p < 0.0001), and were more often operated on via a retroperitoneal approach (61% vs. 40.5%, p < 0.05). Their time in the operating room was less (3.5 vs. 4.5 hr, p < 0.0001), and they had less estimated blood loss (750 vs. 1500 cc, p < 0.001) and fewer transfusions (0.95 vs. 2.45 units, p < 0.0001). Patients without COPD and smaller AAAs that can be repaired via a retroperitoneal approach have a lower incidence of perioperative complications and a shorter hospital stay following open AAA repair. Until long-term results for endografts are available, our data suggest that these patients are well served with an open repair.

INTRODUCTION Endovascular technology has ushered in a new era for the treatment of abdominal aortic aneurysms (AAA). Several studies have demonstrated significant advantages of this new technique with respect to perioperative mortality and morbidity, length of intensive care unit (ICU) and hospital stay, and length of recovery.1-4 There are few data beyond 1 Department of Surgery, Division of Vascular Surgery, Loyola University Medical Center, Maywood, IL, USA. 2 Department of Surgery, Division of Vascular Surgery, The John H. Stroger, Jr. Hospital of Cook County, Chicago, IL, USA. Correspondence to: Apostolos K. Tassiopoulos, MD, 2425 West 22nd Street, Suite 211, Oak Brook, IL 60523, USA, E-mail: [email protected]

Ann Vasc Surg 2004; 18: 218-222 DOI: 10.1007/s10016-003-0083-1
Annals of Vascular Surgery Inc. Published online: 15 March 2004

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5 years, however, regarding the long-term fate of endografts. Recent patient follow-up studies have raised serious concerns about an increased incidence of intermediate and long-term complications requiring lifelong surveillance and, not infrequently, secondary interventions.5-7 Perhaps, the most concerning complication of endovascular repair is rupture, even in patients who follow the currently recommended surveillance guidelines. Open AAA repair, by contrast, has been proven to be a durable and reliable procedure, but historically it has been associated with significant perioperative morbidity and mortality.8-10 A number of recently published studies, however, have challenged the complication rates reported in older series and pointed to the fact that elective traditional open AAA repair can be performed with perioperative morbidity and mortality rates that are significantly lower than those previously reported.11-15

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The purpose of this study was to identify patients with lower morbidity and shorter hospital stay following open AAA repair and to study the factors that may contribute to this favorable outcome.

METHODS We performed a retrospective chart review of all patients who underwent elective infrarenal AAA repair between 1995 and 2000 at our institution. Patients with ruptured AAA or aortoiliac occlusive disease and those who required concomitant celiac, superior mesenteric, or renal artery revascularization were excluded. Patient demographics, preoperative comorbid conditions, intraoperative data, and postoperative course were compared by means of multivariate linear regression analysis. Furthermore, patients were subdivided into two main groups: those who were discharged in 5 or less days, and those whose hospital stay exceeded 5 days. This cutoff was chosen by the authors arbitrarily for two reasons: (a) most uncomplicated procedures in our series resulted in a hospital stay of 5 or less days, and (b) most series of endovascular AAA repair report hospital stays ranging between 2 and 5 days. The comparison between the two groups was performed using chi-squared analysis. A p value <0.05 was considered statistically significant.

RESULTS Patient Characteristics One hundred and fifteen patients fulfilled the inclusion criteria; 94 (81.7%) were male and 21 (18.3%) were female. Twenty-five (21.7%) patients had a history of previous myocardial infarction (MI) and 32 (27.8%) had undergone at least one myocardial revascularization procedure. Twenty-two (19.1%) patients had a history of chronic obstructive pulmonary disease (COPD) and 10 (8.7%) had a serum creatinine >2 mg/dL. The diameter of the aneurysm ranged between 4.6 and 10 cm (mean 6.3 ± 1.5 cm). There was one perioperative death, accounting for an overall mortality of 0.9%. The mean hospital stay in our patient population was 8.1 days. Length of Stay Forty-one patients (35.6%) left the hospital in 5 or less days. Compared to the group with hospital stay >5 days, these patients had a lower incidence of

Predictors of early discharge after AAA repair 219

COPD (7.3% vs. 25.7%, p < 0.05) and smaller-size AAAs (5.6 vs. 6.4 cm, p < 0.0001), and were more often operated on via a retroperitoneal approach (61% vs. 40.5%, p < 0.05). They also had shorter ‘‘wheels in-wheels out’’ operating room (OR) time (3.5 vs. 4.5 hr, p < 0.0001), less estimated blood loss (EBL) (750 vs. 1500 mL, p < 0.0001), less transfusions (0.95 vs. 2.45 units, p < 0.0001), and faster recovery of their gastrointestinal (GI) function (45.5 vs. 110.3 hr, p < 0.001). A detailed comparison between the two groups is presented in Table I. On multivariate linear regression analysis, independent factors predicting a longer hospital stay included (a) a history of COPD and (b) longer operative time. In addition, higher EBL, increased number of blood transfusions, and use of abdominal incision instead of a retroperitoneal approach appeared to prolong hospital stay but failed to reach statistical significance (p = 0.069, 0.055, and 0.11, respectively), perhaps because of the small number of patients included in this study. The results of multivariate linear regression analysis are presented in Table II.

DISCUSSION Endovascular repair of AAAs was first introduced by Parodi et al.1 in 1991 for management of patients with severe comorbidities who were considered high-risk candidates for an open procedure. This original report triggered development of a number of endografts and the wide application of this new procedure, even in patients with no contraindication to open repair. The initial enthusiasm for this new technique was further fueled by reports indicating that it carried a significantly lower perioperative morbidity and mortality rate than that with the traditional open technique.4,16,17 For open procedures, this comparison was based on reports of large cohorts of patients from the 1970s and 1980s. These studies indicated that open elective repair of AAA carried an overall mortality rate of 5-7% and significant perioperative morbidity requiring long ICU stays and hospitalizations. In the last 2-3 years, more recent series of patients who have had open elective AAA repair since the advent of endovascular technology have been published. Many of these reports suggest that, during the past decade, there has been significant improvement in the perioperative morbidity and mortality associated with open AAA repair.11,13,15,18,19 Several centers have reported mortality rates ranging between 0 and 2%.11-15,18,19 This has been attributed to better preoperative risk-stratification and patient

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Table I. Comparison of patients with LOS £5 days and those with LOS >5 daysa Factor

Patients (n) Age (years) Comorbidities Previous MI COPD Renal insufficiency Aneurysm size Iliac artery involvement Renal artery involvement Operative data OR time (hr) Clamp time (min) EBL (mL) IV fluids (mL) Blood transfusion (units) Surgical approach Transabdominal Retroperitoneal Graft type Tube Bifurcated Postoperative data Mechanical ventilation (hr) ICU stay (hr) Return of GI function (hr) Hospital stay (days)

LOS £5 days

LOS >5 days

p

41 71.8

74 70.1

NS

8 2 2 5.5 9 2

17 20 8 6 31 10

(22.9%) (27.1%) (10.8%) (IQR: 5.5-8) (41.9%) (13.6%)

NS <0.05 NS <0.0001 <0.05 NS

(IQR: (IQR: (IQR: (IQR: (IQR:

<0.0001 NS <0.0001 <0.0001 <0.0001

3.5 50 750 4200 0

(19.5%) (4.9%) (4.9%) (IQR: 5-6) (21.9%) (4.9%) (IQR: (IQR: (IQR: (IQR: (IQR:

3-4) 40-61.3) 537.5-1350) 3500-5500) 0-2)

4.5 50 1500 5500 2

3.75-5) 42.5-66.3) 1000-2000) 4450-7000) 1-4)

16 (39%) 25 (61%)

44 (59.5%) 30 (40.5%)

<0.05 <0.05

25 (61%) 16 (39%)

34 (45.9%) 40 (54.1%)

NS NS

0 48 48 4.5

0 84 84 7.5

<0.05 <0.0001 <0.0001 <0.0001

(IQR: (IQR: (IQR: (IQR:

0-0.5) 24-48) 24-60) 4-5)

(IQR: (IQR: (IQR: (IQR:

0-3.63) 57-120) 48-120) 7-11)

IQR, intraquintile range; IV, intravenous; NS, not significant. a Values are medians with IQR. Values in the text are mean values for each variable.

optimization and to improvements in anesthesia, postoperative analgesia, and critical care.9 The rate of one perioperative death in our study (0.9%) compared well with these recent reports. One of the major advantages of endovascular AAA repair is the significantly shorter length of ICU and hospital stay. The mean length of stay (LOS) following this procedure ranges between 2 and 5 days. LOS following open AAA repair by contrast even in recent reports, varies between 3.2 and 11 days, with an average between 7 and 8 days.11-15 Our results are comparable, with a mean LOS of 8.1 days. The major prerequisites for discharge from the hospital after an open AAA procedure are (a) return of GI function, (b) absence of complications, and (c) resumption of a reasonable level of independent activity. Podore and Throop11 have recently reported an average LOS of 3.2 days using a clinical pathway that incorporated early feeding, early ambulation, and selective use of ICU. Our results indicate that patients who were discharged in <5 days had return of their GI function earlier than the rest of patients and had fewer postoperative com-

plications. We identified several other factors associated with longer LOS, including a history of COPD, longer operative time with greater blood loss and larger transfusion volumes, and, perhaps, the use of a midline abdominal incision instead of a retroperitoneal approach (Table II). In this study, patients with longer hospital stay had larger AAAs extending more frequently to the iliac vessels and requiring bifurcated grafts for repair. Larger aneurysms are technically more challenging to repair, and this can explain the longer OR time, increased EBL, and increased number of transfusions seen in this group. The longer OR time could also be responsible for the lengthier ICU stay and the more prolonged postoperative ileus seen in this group. There is still controversy regarding the advantages of operative approach in patients undergoing open AAA repair. Several centers preferentially use the retroperitoneal approach for most of their aortic procedures. We selectively use both approaches according to surgeon’s preference, body habitus, and preoperative evaluation. Our study indicates that use of a retroperitoneal approach resulted in

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Predictors of early discharge after AAA repair 221

Table II. Multivariate linear regression analysis of patients with elective AAA repair

COPD MI AAA size OR time EBL Blood transfusion (units) Abdominal incision Bifurcated graft

Ventilator time (p)

ICU stay (p)

Postoperative ileus (p)

Hospital stay (p)

0.12 0.01 NS 0.03 NS 0.11 NS NS

0.015 NS NS 0.04 NS 0.007 NS NS

NS 0.1 NS 0.001 0.11 NS 0.04 NS

0.03 NS NS 0.001a 0.07 0.055 0.11 NS

NS, not significant, RBC, red blood cell count.

significantly shorter GI function recovery time and that patients with hospital stays <5 days were more often operated on via a retroperitoneal incision. Two prospective studies12,20 have also shown that use of the retroperitoneal incision is associated with earlier return of GI function and shorter hospital and ICU stay. In 1991, in a small prospective, randomized study of 27 patients, Darling et al.20 showed a significant reduction in blood loss (517 vs. 1127 mL), less transfusions (16% vs. 72%), faster return to diet (2.1 vs. 4 days), and a shorter LOS (6.7 vs. 9 days) for patients who had retroperitoneal exclusion for AAA instead of a transperitoneal repair. In a larger series, Sicard et al.12 reported that the retroperitoneal group had fewer overall postoperative complications, and decreased incidence of postoperative ileus. The retroperitoneal group also had shorter ICU stays (2.3 vs. 3.5 days), a trend toward shorter hospitalization (9.9 vs. 12.9 days), and lower total hospital costs. There was no difference in intraoperative complications, postoperative mortality, or long-term survival. Cambria et al.21 however, have contradicted these results, showing no difference in the incidence of major or minor complications, blood loss, recovery of GI function, or duration of hospital stay between the two groups. In recent years, two additional alternatives to the traditional open repair have been introduced. Laparoscopically assisted AAA repair has been performed in a limited number of patients, with few complications and promising results. The technique involves laparoscopic dissection of the aneurysm neck and iliac arteries, followed by open endoaneurysmorraphy through a limited midline incision. Patients require nasogastric decompression for shorter periods postoperatively and their ICU and LOS appear to be shorter.22,23 Perhaps more intriguing is the minimal-incision AAA repair, in which a small midline incision and limited bowel retraction are also used. This technique has

been used in a larger number of patients and compared with the laparoscopic approach, and has been shown to shorten postoperative ileus and LOS.23,24 A significant disadvantage of these techniques is the fact that they are applicable only when aneurysm anatomy is favorable. We believe that although the perioperative morbidity associated with endovascular AAA repair is certainly lower than that with the traditional open technique, the latter is well tolerated by most patients. Recent reports have shown excellent results in terms of perioperative morbidity and mortality when the procedure is performed by experienced surgeons in specialized centers.15,25 Patients with no history of COPD who are good operative candidate, especially those with a favorable anatomy that would contribute to a shorter, uncomplicated procedure, appear to have a particularly favorable outcome. The long-term performance of endografts is still unknown and the relatively high incidence of graft-related complications requires continuous surveillance and, not infrequently, secondary interventions. Therefore, fit patients with AAAs should give serious consideration to the traditional open procedure, which has an established, excellent long-term result, until endografts pass the test of time.

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