Retroperitoneal versus transperitoneal approach for repair of abdominal aortic aneurysms

Transperitoneal versus retroperitoneal approach for open abdominal aortic aneurysm repair in the targeted vascular National Surgical Quality Improvement Program

OBJECTIVE

We sought to compare current practices in patient selection and 30-day outcomes for transperitoneal and retroperitoneal abdominal aortic aneurysm (AAA) repairs.

METHODS

All patients undergoing elective transperitoneal or retroperitoneal surgical repair for AAA between January 2011 and December 2013 were identified in the Targeted Vascular National Surgical Quality Improvement Program database. Emergency cases were excluded. Baseline characteristics, anatomic details, and intraoperative and postoperative outcomes were evaluated among those with infrarenal or juxtarenal AAA only.

RESULTS

We identified 1135 patients: 788 transperitoneal (69%) and 347 retroperitoneal (31%). When only infrarenal and juxtarenal AAAs were evaluated, the retroperitoneal patients were less likely to have an infrarenal clamp location (43% vs 68%) and had more renal revascularizations (15% vs 6%; P < .001), more visceral revascularizations (5.6% vs 2.4%; P = .014), and more lower extremity revascularizations (11% vs 7%; P = .021) compared with the transperitoneal approach. Postoperative mortality and return to the operating room were similar. Transperitoneal patients had a higher rate of wound dehiscence (2.4% vs 0.4%; P = .045), and retroperitoneal patients had higher incidence of pneumonia (9% vs 5%; P = .034), transfusion (77% vs 71%; P = .037), and reintubation (11% vs 7%; P = .034), and a longer median length of stay (8 vs 7 days; P = .048). After exclusion of all concomitant procedures, only transfusions remained more common in the retroperitoneal approach (78% vs 70%; P = .036). Multivariable analyses showed only higher rates of reintubation in the retroperitoneal group (odds ratio, 1.7; 95% confidence interval, 1.0-3.0; P = .047).

CONCLUSIONS

The retroperitoneal approach is more commonly used for more proximal aneurysms and was associated with higher rates of pneumonia, reintubation, and transfusion, and a longer length of stay on univariate analyses. However, multivariable analysis demonstrated similar results between groups. The long-term benefits and frequency of reinterventions remain to be proven.

Management of Juxtarenal Aortic Aneurysms and Occlusive Disease with Preferential Suprarenal Clamping Via a Midline Transperitoneal Incision: Technique and Results

Surgical management of juxtarenal aortic (JR-Ao) aneurysms and occlusive disease may include supraceliac aortic clamping, a retroperitoneal approach, or medial visceral rotation. The authors report their results using preferential direct suprarenal aortic clamping via a midline transperitoneal incision. Between July 1, 1992, and July 31, 2001, they treated 58 patients with JR-Ao disease (44 aneurysmal, 14 occlusive) via a midline incision without medial visceral rotation. Preferential suprarenal aortic clamping was used in 53 cases (42 proximal to both renal arteries, 11 proximal to the left renal artery only) and supraceliac or supramesenteric clamping in 5 cases when there was insufficient space for an aortic clamp between the superior mesenteric artery and renal arteries. This strategy avoided mesenteric ischemia associated with supraceliac clamping in the majority of cases and afforded better exposure of the right renal artery than obtainable with a left retroperitoneal approach or medial visceral rotation. Eleven patients underwent concomitant renal revascularization. Critical adjuncts included the following: (1) selective left renal vein (LRV) division if the vein stump pressure was <35 mm Hg (suggesting sufficient renal venous collaterals existed), (2) bilateral renal artery occlusion during aortic clamping to prevent thromboembolism, (3) flushing of aortic debris before restoring renal perfusion, and (4) routine administration of perioperative intravenous mannitol and renal-dose dopamine. Patients with type IV thoracoabdominal aneurysms, ruptured aneurysms, or JR-Ao disease approached via a retroperitoneal incision (severely obese patients, re-do aortic surgery) were excluded. No patients died or required dialysis during their hospital stay. The LRV was divided in 12 (21%) cases and reanastomosed in 2 cases (elevated stump pressures). The average suprarenal clamp time was 26 minutes (range, 10–60). Postoperative serum creatinine remained >0.5 ng/dL above baseline in 3 (5%) patients. These results support suprarenal aortic clamping with a midline transperitoneal incision as the optimal strategy for treating juxtarenal aortic aneurysms and occlusive disease. The authors believe that selective left renal vein division enhances juxtarenal aortic exposure, and routine administration of renal protective agents, along with occlusion of both renal arteries during suprarenal aortic clamping, are critical adjuncts in performing these operations.

Left retroperitoneal aortic aneurysm repair in patients unsuitable for endovascular treatment

BACKGROUND

This study aims to evaluate the contemporary outcome of left open retroperitoneal (RP) abdominal aortic surgery over a 7-year time period in patients with difficult anatomy unsuitable for endovascular aneurysm repair (EVAR).

METHODS

Eighty-four consecutive patients unsuitable for EVAR/FEVAR underwent left RP open aortic surgery. Of these, 44 (52%) required an infrarenal cross-clamp, 17 (20%) a suprarenal cross-clamp and 15 (18%) a supracoeliac cross-clamp. Eight (10%) were thoracoabdominal aneurysms.

RESULTS

There were four mortalities within 30 days (4.8%). Two occurred in patients with a supracoeliac cross-clamp, one in a suprarenal cross-clamp (total suprarenal mortality 10%) and one in an infrarenal cross-clamp. Four patients required prolonged ventilatory support (>10 days). Three patients (9%) from the suprarenal group developed post-operative renal dysfunction, one of these required permanent dialysis. Paralytic ileus occured in two patients (2%) and was secondary to ischaemia in both cases.

CONCLUSION

There will always remain a small group of patients best treated by open aortic surgery. By definition, these are complex, difficult cases and are decreasing in number. However, in vascular units regularly performing the RP approach, excellent results can be obtained. This series provides further evidence for centralization of vascular services.

Retroperitoneal repair of abdominal aortic aneurysms offers postoperative benefits to male patients in the Veterans Affairs Health System

BACKGROUND

Transperitoneal (TP) and retroperitoneal (RP) approaches have equal efficacy in elective open abdominal aortic aneurysm (AAA) repair. The effect of open operative approach on patient-specific outcomes after AAA repair was tested.

METHODS

Consecutive patients undergoing open AAA repair at the Veterans Affairs Tennessee Valley Healthcare System between January 2000 and August 2008 were retrospectively reviewed. Analysis was performed to examine the effects of demographic and clinical covariates on postoperative outcomes.

RESULTS

A total of 106 patients were identified: 54 with TP approach and 52 with RP approach. Demographics and preoperative comorbidities were equivalent (p > or = 0.10), with the exception of chronic obstructive pulmonary disease which was more prevalent in the TP group (61 vs. 40%). Operative times were longer in the TP group (4.6 vs. 3.5 hours; p < 0.01); however, significantly more TP patients had reconstruction with a bifurcated graft (72 vs. 2%; p < 0.01). Postoperative nasogastric tube decompression times were shorter in the RP group (1 vs. 3 days; p < 0.01), and RP approach led to a quicker return to preoperative diet (4 vs. 6 days; p = 0.05). Patients undergoing RP repair developed fewer incisional hernias (2 vs. 15%; p = 0.03).

CONCLUSION

RP approach to AAA repair offers patients faster return of bowel function and is associated with fewer incisional hernias.

Infected pancreatic necrosis after extraperitoneal abdominal aortic aneurysm repair: report of a case

We report a case of acute necrotizing pancreatitis after extraperitoneal repair of an abdominal aortic aneurysm (AAA). Acute pancreatitis (AP) is an uncommon complication of vascular surgery; however, managing its local and general consequences, including the eventual pancreatic abscess and the risk of prosthetic infection, presents formidable challenges.

The immunomodulatory effects of laparoscopic surgery

Laparoscopic alternatives to conventional surgical procedures confer many advantages to patients including reduced postoperative pain, shortened convalescence and, perhaps, improved disease-related outcomes. The diminished degree of immune dysfunction apparent with these techniques may underpin these beneficial aspects. However, minimal access is accompanied by various ancillary anesthetic and mechanical associations (including the induction of a carbon dioxide pneumoperitoneum), which must be considered in addition to reduced tissue trauma when attempting to correlate cause with effect. Furthermore, the opportunity to establish causation between the immunomodulatory aspects of laparoscopy and subsequent clinical outcome by prospective, randomized study is difficult because of the rapid incorporation of minimal access techniques into clinical practice. Therefore, experimental in vitro and in vivo studies must be used to complement the limitations of clinical studies in this area. Although the initial investigations into the immunological effects of laparoscopy are encouraging, many of the intricacies associated with this approach still await elaboration.

Open aneurysm repair at an endovascular center: value of a modified retroperitoneal approach in patients at high risk with difficult aneurysms

OBJECTIVE

This study was undertaken to evaluate elective open abdominal aortic aneurysm (AAA) repair and the role of a modified retroperitoneal approach in a high-volume endovascular center.

METHODS

We reviewed prospectively collected data for 175 elective infrarenal open AAA repairs performed over 6 years. A transperitoneal approach was used in 118 procedures, and a modified retroperitoneal approach was used in 57 procedures. The incisional modification, which facilitated repair in patients with massive obesity, scarring, or ventral hernia, included a higher, more posterolateral location in the ninth intercostal space. Risk factors that added to the difficulty of the repair included aneurysms with a short (<1 cm) or no aortic neck in 45 patients; large, angled or flared aortic neck in 32 patients;, tortuous and calcified iliac arteries in 6 patients; morbid obesity in 10 patients; low ejection fraction (15%-30%) in 14 patients; chronic obstructive pulmonary disease, with forced expiratory volume at 1 second less than 55% in 4 patients; previous laparotomy in 18 patients; previous left-sided colectomy in 11 patients; large right iliac aneurysm in 8 patients; large ventral hernia in 8 patients; pelvic irradiation in 4 patients; failed endovascular repair in 5 patients; and previous failed open repair attempt in 2 patients. Many of these factors occurred with significantly greater frequency (P =.04-.001) in the retroperitoneal group. All factors were correlated with outcome.

RESULTS

Despite these risk factors, overall 30-day mortality was 3.5% (retroperitoneal group, 3.8%), and mean length of hospital stay was 9 days (retroperitoneal group, 8 days). There was no significant correlation between mortality or length of stay and any of the mentioned risk factors (P >.2).

CONCLUSION

In the era of endovascular aneurysm exclusion, open AAA repair is generally used to treat anatomically complex or difficult aneurysms, many of which are present in patients at high risk. Despite this combination of anatomic and systemic risk factors, the modified retroperitoneal approach facilitates treatment in difficult circumstances and enables open AAA repair to be performed with acceptable mortality and morbidity.

Endoluminal graft repair for abdominal aortic aneurysms in high-risk patients and octogenarians: is it better than open repair?

OBJECTIVE

To analyze the short-term and midterm results of open and endoluminal repair of abdominal aortic aneurysms (AAA) in a large single-center series and specifically in octogenarians.

METHODS

Between January 1997 and October 2000, 470 consecutive patients underwent elective repair of AAA. Conventional open repair (COR) was performed in 210 patients and endoluminal graft (ELG) repair in 260 patients. Ninety of the patients were 80 years of age or older; of these, 38 underwent COR and 52 ELG repair.

RESULTS

Patient characteristics and risk factors were similar for both the entire series and the subgroup of patients 80 years or older. The overall complication rate was reduced by 70% or more in the ELG versus the COR groups. The postoperative death rate was similar for the COR and ELG groups in the entire series and lower (but not significantly) in the ELG 80 years or older subgroup versus the COR group. The 36-month rates of freedom from endoleaks, surgical conversion, and secondary intervention were 81%, 98.2%, and 88%, respectively.

CONCLUSION

The short-term and midterm results of AAA repair by COR or ELG are similar. The death rate associated with this new technique is low and comparable, whereas the complication rate associated with COR in all patients and those 80 years or older in particular is greater and more serious than ELG repair. Long-term results will establish the role of ELG repair of AAA, especially in elderly and high-risk patients.

Surgical management of abdominal aortic aneurysm

Abdominal aortic aneurysms (AAA) are increasingly common in the aging population. While the etiology of abdominal aortic aneurysms is unknown, there is growing evidence that suggests an immune response. The majority of AAA are asymptomatic and when treated are standard open surgical procedures. The overall mortality rate is 5% or less. The current recommendations for the treatment of aneurysms are based on diameter: diameters exceeding 5 cm in good-risk younger patients should be treated. Aortic aneurysms tend to enlarge over time with a growth-rate between 0.2 and 0.4 mm per year. Once rupture occurs mortality is estimated to exceed 75%, with half of the patients dying prior to arriving at the hospital and the remaining one-half following surgical correction. Recently, minimally invasive techniques have been developed to treat AAA in high-risk patients. These techniques involve the use of covered stented grafts. Current clinical investigations are underway both in this country and in Europe, which have yielded promising results. However, long-term complications are unknown. Currently, aortic aneurysms are best treated with open surgical management.

Cost-effective aortic exposure: a retroperitoneal experience

In this study we investigated whether the surgical approach to infrarenal aortic aneurysm (IAA) repair significantly affects in-hospital morbidity and cost. The study comprised a consecutive series of 96 patients with elective repair of an IAA by two vascular surgeons using an established protocol from March 1995 to March 1999. The outcomes and costs for 50 patients with transperitoneal (TP) exposure were compared with those for 46 patients with retroperitoneal (RP) exposure, all of whom were in a tertiary care center, in a university hospital. Hospital and ICU days, perioperative complications, and cost were measured. All patients followed the same protocol except for intraoperative aortic exposure. There was no significant difference between TP and RP groups with regard to demographic features (all p-values > 0.12), mean IAA size (p = 0.41) or mean operative blood loss (p = 0.89). Incidence of postoperative complications was similar between the groups (11 in TP and 6 in RP; p = 0.29). However, a trend without statistical significance was noted in the incidence of pulmonary complications (7 in TP and 2 in RP; p = 0.11). Mean ICU days (4 vs. 2; p = 0.004) and hospital days (11 vs. 6; p = 0.002) were significantly longer after TP aortic exposure than after the RP approach. Mean total hospital cost was significantly reduced for patients having RP IAA repair compared to TP IAA repair (mean cost difference = $5,527; p = 0.016). Retroperitoneal exposure for IAA repair is associated with decreased pulmonary complications, significantly shorter ICU and hospital days, and significantly decreased hospital cost compared to transperitoneal aortic exposure. In the future, RP exposure for IAA repair should be the benchmark for comparison of any new techniques.

The incidence, natural history, and outcome of secondary intervention for persistent collateral flow in the excluded abdominal aortic aneurysm

OBJECTIVE

The goal of abdominal aortic aneurysm (AAA) repair is the prevention of rupture. Exclusion of the infrarenal AAA by means of operation or endovascular graft placement is an alternative therapy to achieve this goal. However, thrombosis of the excluded aneurysm sac does not always occur and further intervention may be needed. This study examines the efficacy of available screening methods to detect the persistence of aneurysm sac flow and the outcome of secondary procedures to treat this problem.

METHODS

During the past 14 years, 1218 patients have undergone operative retroperitoneal exclusion of AAA. To date, 48 patients have been found to have persistent flow in the excluded AAA sac with duplex scanning. Twenty-seven patients underwent surgical intervention, and seven of these procedures were performed for rupture. Six patients have undergone treatment with interventional techniques (four successfully). The patients were evaluated for preoperative angiographic, anatomic, and comorbid factors that may have predisposed them to failed exclusion. Also, perioperative morbidity and mortality, estimated blood loss, and survival were assessed in the patients who required surgical treatment.

RESULTS

There were no perioperative parameters that correlated with postoperative persistent flow in the excluded AAA sac. The mean time to secondary intervention was 51 months (range, 2 to 113 months). Two patients had false-negative computed tomographic angiogram results, eight patients had false-negative angiogram results, and six patients had duplex scan examinations that had initially negative results that were then positive for flow in sac. Reoperation had a 7.4% mortality rate (two deaths) and a median blood loss of 2600 mL, as compared with 500 mL for primary procedures.

CONCLUSION

Secondary operations for patent excluded aortic aneurysm sacs have higher mortality and intraoperative blood loss rates than do primary procedures for AAA repair. The localization of branch leaks with computerized tomographic angiography, angiography, and duplex scanning were imprecise, and better methods are needed to adequately diagnose patent sacs. Expansion of AAA sac may be the only reliable factor.

Comparison between the transabdominal and retroperitoneal approaches for aortic reconstruction in patients at high risk

PURPOSE

The purpose of this study was to compare the transabdominal approach with the retroperitoneal approach for elective aortic reconstruction in the patient who is at high risk.

METHODS

From January 1992 through January 1997, 148 patients underwent aortic operations: 92 of the patients were classified as American Society of Anesthesia (ASA) class IV. Forty-four operations on the patients of ASA class IV were performed with the transabdominal approach (25 for abdominal aortic aneurysms and 19 for aortoiliac occlusive disease), and 48 operations were performed with the retroperitoneal approach (27 for abdominal aortic aneurysms and 21 for aortoiliac occlusive disease). There were no significant differences between the groups for comorbid risk factors or perioperative care.

RESULTS

Among the patients of ASA class IV, eight (8.7%) died after operation (retroperitoneal, 3 [6.26%]; transabdominal, 5 [11.3%]; P =.5). There was no difference between groups in the number of pulmonary complications (retroperitoneal, 23 [47.9%]; transabdominal, 19 [43.2%]; P =.7) or in the development of incisional hernias (retroperitoneal, 6 [12.5%]; transabdominal, 5 [11.3%]; P =.5). The retroperitoneal approach was associated with a significant reduction in cardiac complications (retroperitoneal, 6 [12.5%]; transabdominal, 10 [22.7%]; P =.004) and in gastrointestinal complications (retroperitoneal, 5 [8.3%]; transabdominal, 15 [34.1%]). Operative time was significantly longer in the retroperitoneal group (retroperitoneal, 3.35 hours; transabdominal, 2.98 hours; P =.006), as was blood loss (retroperitoneal, 803 mL; transabdominal, 647 mL; P =.012). The patients in the retroperitoneal group required less intravenous narcotics (retroperitoneal, 36.6 +/- 21 mg; transabdominal, 49.5 +/- 28.5 mg; P =.004) and less epidural analgesics (retroperitoneal, 39.5 +/- 6.4 mg; transabdominal, 56.6 +/- 9.5 mg; P =.004). Hospital length of stay (retroperitoneal, 7.2 +/- 1.6 days; transabdominal, 12.8 +/- 2.3 days; P =.024) and hospital charges (retroperitoneal, $35,587 +/- $980; transabdominal, $54,832 +/- $1105; P =.04) were significantly lower in the retroperitoneal group. The survival rates at the 40-month follow-up period were similar between the groups (retroperitoneal, 81.3%; transabdominal, 78.7%; P =.53).

CONCLUSION

In this subset of patients who were at high risk for aortic reconstruction, the postoperative complications were common. However, the number of complications was significantly lower in the retroperitoneal group. Aortic reconstruction in patients of ASA class IV appears to be more safely and economically performed with the retroperitoneal approach.

Cardiac troponin I and Q-wave perioperative myocardial infarction after coronary artery bypass surgery

OBJECTIVE

To monitor cardiac troponin I (cTnI), a newly developed biochemical index for cardiac damage, in patients during and after coronary artery bypass surgery (CABS) to determine whether the measurement of the serum levels of this marker could be of value in formulating an early diagnosis of Q-wave perioperative myocardial infarction (PMI).

DESIGN

Prospective study with sequential measurements of biological markers in a selected surgical patient group.

SETTING

University research laboratory and general university hospital (Cardiac Surgery Unit and Anesthesiology and Reanimation Unit).

PATIENTS

Forty-two patients undergoing elective CABS without concomitant valvular replacement.

INTERVENTIONS

There were no interventions required for this study. However, patients entered into the study had CABS, sequential arterial blood samples, ECG recordings, and echocardiograms performed.

MEASUREMENTS AND MAIN RESULTS

Pre-, intra-, and postoperative (up to 48 hrs) measurements of cardiac troponin I, MB-CK, and total creatine kinase, as well as serial electrocardiograms and echocardiograms. Perioperative infarction was assessed as the development of new persistent regional wall motion abnormalities in echocardiography together with electrocardiographic alterations and MB-CK increases. Eight patients had Q-wave PMI. All PMI patients had elevated peak cTnI values (all >9.2 ng/mL), whereas the 34 nonPMI patients had peak values <9.0 ng/mL; therefore, sensitivity and specificity (with a 9.0 ng/mL cut-off value) are 100%. MB-CK measurement peak values did not demonstrate such a high specificity and sensitivity.

CONCLUSIONS

Because of its high specificity and sensitivity, serial measurements of cTnI provide a rapid and accurate method for confirming or excluding the diagnosis of perioperative myocardial injury. cTnI evaluation can therefore be used both as an independent prognostic marker for patients undergoing cardiac surgery and as a powerful tool for detecting smaller PMIs often missed with standard PMI diagnostic criteria.

Assessment of operative risk for patients with advanced lung disease

Increasingly, patients with advanced lung disease are being offered operative procedures. The assessment of the perioperative risk of these patients must include not only the assessment of their lung disease, but the assessment of the patient's cardiovascular disease, their age, and their other medical problems. Knowledge of the stress of particular surgical procedures is also of importance in risk assessment, and is addressed in this article.

Midline extraperitoneal approach for elective abdominal aortic aneurysm repair

The incidence of abdominal aortic aneurysms (AAA) is rising and elective repair is becoming more commonplace. We describe a new, simple midline extraperitoneal approach for AAA repair. It is particularly suitable for patients who have an inflammatory AAA, abdominal adhesions or a horseshoe kidney. This approach provides excellent exposure to the whole aortoiliac system without the need for separate incisions, whilst retaining the potential advantages of the extraperitoneal approach.

Disseminated intravascular coagulation associated with acute ischemic hepatitis after elective aortic aneurysm repair: comparative analysis of 10 cases

OBJECTIVE

To assess the characteristics of patients with perioperative disseminated intravascular coagulation (DIC) and acute ischemic hepatitis after elective aortic aneurysm repair (AAR).

DESIGN

A retrospective case-control study.

SETTING

A single tertiary referral center.

PARTICIPANTS

Between 1982 and 1993, 1966 patients underwent elective AAR. Of these, 10 patients (eight with abdominal and two with thoracoabdominal aneurysms) developed DIC and acute elevation of serum transaminases consistent with acute ischemic hepatitis during or shortly after surgery. The control group included 30 patients matched by age, sex, year of surgery, and aneurysm type and size.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

None of the patients in either group had preoperative hemostatic abnormalities or other causes for DIC. There was no difference between the two groups in the duration of aortic cross-clamping. In all study patients, severe coagulopathy or systemic hypotension developed after the aortic cross-clamp was released. This resulted in significantly increased surgery time after unclamping (p < 0.001), and increased estimated blood loss (p < 0.001). DIC developed within 24 hours, and mean concentrations of aspartate transaminase (4,021 +/- 3,579 IU/L) and lactate dehydrogenase (4,332 +/- 2,903 IU/L) peaked on the second postoperative day. Nine (90%) of the study patients required repeat operations (seven for bleeding), and all of them died; the median survival time was 6 days (mean, 8.3 +/- 8.2 days). Only one patient in the control group needed a repeat operation. Liver infarction or necrosis was seen in all seven patients who underwent autopsy or biopsy.

CONCLUSIONS

The combination of DIC and acute ischemic hepatitis ("hepatohemorrhagic syndrome") rarely occurs after elective AAR and is associated with a very high mortality rate. DIC was temporally related to the release of the aortic cross-clamp. The cause-effect relationship of this rare syndrome cannot be explained by operative course before the release of the aortic cross-clamp.

Fate of the excluded abdominal aortic aneurysm sac: long-term follow-up of 831 patients

PURPOSE

Nonresective treatment of the infrarenal abdominal aortic aneurysm by proximal and distal ligation of the aneurysm sac (exclusion) combined with aortic bypass has been previously reported. A 10-year experience with 831 patients undergoing this procedure was reviewed.

METHODS

From 1984 to 1994, 831 (761 elective, 70 urgent) of 1103 patients being treated for abdominal aortic aneurysm underwent repair with the retroperitoneal exclusion technique. Perioperative morbidity and mortality, estimated blood loss, transfusion requirements, natural history of the excluded aneurysm sac, and long-term survival were all assessed.

RESULTS

The operative mortality rate for patients undergoing exclusion and bypass was 3.4%. The incidence of nonfatal perioperative complications was 5.2%. Colon ischemia requiring resection occurred in 2 (0.2%) of the 831 patients. Estimated blood loss was 638 +/- 557 cc (50 to 330 cc). On follow-up 17 (2%) patients were found to have patent aneurysm sacs as detected by duplex examination. Fourteen patients required surgical intervention. No cases of graft infection or aortoenteric fistula have been noted.

CONCLUSION

Retroperitoneal exclusion and bypass is a viable alternative to traditional open endoaneurysmorraphy in surgery for abdominal aortic aneurysm. Most excluded aneurysm sacs have thrombosis without any long- or short-term complications; however, in a small number of patients delayed rupture of patent aneurysm occurs, thus emphasizing the need for diligent follow-up and appropriate intervention.

Current status of the use of retroperitoneal approach for reconstructions of the aorta and its branches

OBJECTIVE

The objective of this article is to determine whether retroperitoneal approach for aortic surgery has certain physiologic, technical advantages.

SUMMARY BACKGROUND DATA

The retroperitoneal approach for abdominal aortic reconstruction classically had been reserved for select patients with either high-risk comorbid disease or specific anatomic problems that preclude the transabdominal approach. With increasing appreciation of the physiologic, anatomic, and technical advantages of the extended posterolateral retroperitoneal approach, the authors have expanded its use for repair of all types of aortic visceral and renal artery disease as well as ruptured abdominal aortic aneurysm and infected aortic grafts.

METHODS

From January 1981 to September 1995, 2340 retroperitoneal aortoiliac reconstructions were performed in 2243 patients. Aortic reconstructions accounted for 1756 cases: 1109 for elective abdominal aortic aneurysms, 210 for ruptured and symptomatic aortic aneurysms, 399 for occlusive disease, 18 for infected aortic grafts, and 20 for other indications. Iliofemoral disease was the indication for 584 procedures. As experience was gained, this approach also was used for 417 renal and 50 celiac and superior mesenteric artery reconstructions.

RESULTS

The mean age was 67 years with 1590 men and 653 women. Overall mortality was 5.2% for all aortic cases: 2.4% for elective, 12.6% for symptomatic, and 29.0% for ruptured aortic aneurysms. Major complications occurred in 12.5% of the elective procedures and in 38.3% of emergency procedures. Over the past 5 years, the average length of hospital for uncomplicated elective abdominal aortic aneurysms was 6.1 days, intensive care unit stay was 0.7 day, and diet was resumed by postoperative day 1. Five-year graft patency was 99% for aneurysms and 95% for occlusive disease.

CONCLUSIONS

The retroperitoneal approach offers certain physiologic advantages associated with minimal disturbance of gastrointestinal and respiratory function, thereby reducing the length of intensive care unit and hospital stay. In addition, its technical advantages and flexibility facilitates visceral and juxtarenal aortic reconstructions without the need for thoracotomy.

Advantages of using the midline incision right retroperitoneal approach for abdominal aortic aneurysm repair

This study was conducted to compare the midline incision right retroperitoneal approach for repairing abdominal aortic aneurysms (AAA) with the transperitoneal approach. The intra- and postoperative course of 15 patients who underwent AAA repair using the transperitoneal approach between 1987 and 1991 and another 15 patients who underwent AAA repair using the retroperitoneal approach between 1991 and 1994 were evaluated. The incidence of postoperative wound complications was also assessed. There was no operative or hospital death in either group. Although a significantly longer interval was required from the incision to the aortic clamp using the extraperitoneal method, there were no statistical differences in the aortic clamping time, total operation time, or blood loss between the two groups. On the other hand, there was a statistically significant improvement in bowel function and a significant reduction in the length of postoperative hospitalization following the extraperitoneal procedure. Furthermore, no wound complications such as those associated with the left flank incision developed after the extraperitoneal procedure. Thus, we recommend the midline incision right retroperitoneal approach for AAA as it does not involve muscle division and is associated with fewer complications.

Preliminary experience with the Endovascular Technologies bifurcated endovascular aortic prosthesis in a calf model

PURPOSE

The purpose of this study was to develop a bifurcated endoluminal prosthesis for transfemoral placement in the aortoiliac position with a large-animal model that would simulate human implantation.

METHODS

Fifteen calves (160 to 200 kg) underwent bilateral femoral artery exposure and transfemoral placement in the aortoiliac position of a bifurcated Dacron prosthesis, inserted through a 26F sheath with an over-the-bifurcation guide wire to retrieve the contralateral limb and secured proximally and distally with self-expanding attachment systems. The preferred location was determined before implantation and compared with final implant location by caliper measurements and angiography. Events during implantation, maneuvers used to accomplish accurate deployment, and final results, as judged by angiography and clinical evaluation, were recorded. Four animals survived and were used for chronic evaluation and healing by gross and microscopic studies.

RESULTS

All grafts (n = 15) were patent at the end of the procedure. All (n = 7) noncrimped grafts had minor kinks in areas of curvature, whereas eight of eight crimped grafts (device modification) had none. Torque control of the body and individual limbs was necessary to correct twists before deployment in 10 of 15 grafts, with two greater than 30-degree twists remaining, which did not appear to affect flow. One implant was entirely deployed in the aorta because of parallax error, subsequently avoided by use of a marker board placed dorsally. Three premature deployments occurred, corrected by attachment system lock modification. The mean final implant position was within 2.9 +/- 1.4 mm (aortic), 1.6 +/- 1.1 mm, and 1.5 +/- 0.8 mm (contralateral and ipsilateral iliac limbs, respectively) of the intended position. Three of four animals intended for long-term evaluation were killed prematurely because of clinically evident spinal cord ischemia. Histologic sections at 2 weeks showed early wall repair without inflammatory cells and pannus ingrowth across the anastomosis.

CONCLUSION

We conclude that implantation of a bifurcated endovascular prosthesis through the bilateral femoral approach is possible, provided the intended aortic implantation site (neck) is at least 12 mm in length (mean +/- 2 SD each direction). Torque control of each portion of the device will be needed in the majority of instances, with attention to parallax effect necessary for optimal placement. This animal model is not suitable for chronic graft evaluation because of its sensitivity for spinal cord ischemia. Healing data suggest graft incorporation similar to that of a surgically placed prosthesis.

Hypothermia during elective abdominal aortic aneurysm repair: the high price of avoidable morbidity

PURPOSE

Adverse outcomes apparently associated with hypothermia led us to examine patients undergoing elective abdominal aortic aneurysm (AAA) repairs to test the hypothesis that hypothermia (temperature less than 34.5 degrees C) is associated with increased morbidity and excess mortality rates.

METHODS

Two hundred sixty-two elective AAA repairs were retrospectively reviewed for preoperative and intraoperative risk factors. Core temperature, age, Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scores (raw and temperature-adjusted), fluid resuscitation, and perioperative organ dysfunction were recorded prospectively. Outcome measures included lengths of stay in the intensive care unit and in the hospital, and hospital mortality rates.

RESULTS

Except for a higher risk of hypothermia in women (p < 0.05), by univariate analysis, preoperative risk factors were similar in patients in the hypothermic and normothermic groups. After operation, patients with hypothermia had significantly greater APACHE scores (p < 0.0001), and patients in the hypothermic nonsurvivor group took significantly longer to rewarm (p < 0.05), suggesting marked hypoperfusion. Patients with hypothermia had significantly greater fluid (p < 0.05), transfusion (p < 0.01), vasopressor (p < 0.05), and inotrope (p < 0.05) requirements, resulting in significantly higher incidences of organ dysfunction (53.0% vs 28.7%, p < 0.01) and death (12.1% vs 1.5%, p < 0.01) and markedly prolonged lengths of stay in the unit (9.2 +/- 2.0 vs 5.3 +/- 0.6, p < 0.05) and in the hospital (24.3 +/- 2.9 vs 15.0 +/- 0.08, p < 0.01). By multivariate analysis, female gender (p = 0.004) was the only predictor of intraoperative hypothermia, whereas initial hypothermia was significantly predictive of both prolonged hypothermia and development of organ failure (p < 0.05). Organ failure (p < 0.05) and acute myocardial infarction (p < 0.01) were independent predictors of death.

CONCLUSIONS

After AAA repair, patients with hypothermia have multiple physiologic derangements associated with adverse outcomes. Although multiple etiologic factors are interacting, body temperature is one variable that should be controlled during aortic surgery.

Results of an exclusion technique for treatment of abdominal aortic aneurysm

An exclusion technique for the treatment of abdominal aortic aneurysm was used in six patients considered to be at high operative risk mainly because of chronic pulmonary disease. There were no deaths or immediate major complications. Thrombosis of the aneurysm was achieved in four of the six patients. However, in three cases, repeated percutaneous embolization was required to produce thrombosis. One patient developed a secondary rupture of a persisting infrarenal sac resulting from a patent inferior mesenteric artery. This patient was successfully managed by ligature of the infrarenal portion of the abdominal aorta through a median laparotomy. This study emphasizes the limits and the risks of the exclusion technique.

Retroperitoneal approach used exclusively with epidural anesthesia for infrarenal aortic disease

BACKGROUND

The retroperitoneal approach for elective infrarenal aortic procedures is an attractive alternative to the standard transperitoneal approach. In an effort to limit the number of extraneous influences on patient outcome, this approach was performed using epidural anesthesia without the use of endotracheal intubation or general anesthesia.

METHODS

From June 1991 through July 1993, 62 consecutive patients with aorto-occlusive or aorto-iliac disease underwent infrarenal aortic repair using the retroperitoneal approach. Epidural anesthesia was used exclusively in all cases. Patients were evaluated for age, sex, comorbid conditions, morbidity, operating time, blood loss, ileus, and length of hospital stay.

RESULTS

There were 29 aortobiiliac bypasses, 18 aortobifemoral bypasses, and 15 aortic tube grafts. Three patients had an associated renal artery procedure performed. There were 48 men and 14 women. The average age was 74.2 years (range 30 to 88). Comorbid conditions including smoking (69%), coronary artery disease (61%), hypertension (61%), prior myocardial infarction (43%), chronic obstructive pulmonary disease (35%), prior surgery (27%), diabetes mellitus (24%), and a history of cancer (8%) were identified. The average length of surgery was 2 hours and 10 minutes (range 1 hour 20 minutes to 3 hours 15 minutes). The average blood loss was 510 mL (range 200 to 4,000). A nasogastric tube was not used in any patient perioperatively, and oral feeding was started on average by postoperative day 2. The average intensive care unit stay was 1.3 days (range 1 to 7). A mortality rate of 1.6%, and major complication rate of 11% were found. None were of pulmonary nature, which may be ascribed to the absence of endotracheal intubation or general anesthesia. A minor complication rate of 19% was achieved under the presented method. The average hospital stay was 7.7 days (range 5 to 15).

CONCLUSION

No large series using the retroperitoneal approach exclusively under epidural anesthesia has been reported. Recent literature on the retroperitoneal approach makes use of general anesthesia with/without epidural anesthesia. This review supports our contention that the procedure of choice for elective infrarenal aortic surgery is the retroperitoneal approach utilizing epidural anesthesia in the absence of endotracheal intubation and general anesthesia. There is a decrease in the physiologic disturbances associated with general anesthesia, notably pulmonary and gastrointestinal, when only epidural anesthesia is used. This translated into a low complication rate, improved patient comfort, early hospital discharge, and subsequent lower costs.

Diagnosis of perioperative myocardial infarction with measurement of cardiac troponin I

BACKGROUND

Perioperative myocardial infarction is the most common cause of morbidity and mortality in patients who have had noncardiac surgery, but its diagnosis can be difficult. The present study was designed to determine whether the measurement of serum levels of cardiac troponin I, a highly sensitive and specific marker for cardiac injury, would help establish the diagnosis of myocardial infarction.

METHODS

We obtained preoperative measurements of MB creatine kinase, total creatine kinase, and cardiac troponin I, in addition to base-line electrocardiograms and two-dimensional echocardiograms, in 96 patients undergoing vascular surgery and 12 undergoing spinal surgery. Blood samples were obtained every 6 hours for at least the first 36 hours after surgery, and electrocardiograms were obtained daily; a second echocardiogram was obtained approximately three days after surgery. The appearance of a new abnormality in segmental-wall motion on the postoperative echocardiogram (that is, an abnormality that had not been seen on the preoperative echocardiogram) was considered to be indicative of perioperative infarction.

RESULTS

Eight patients who underwent vascular surgery had new abnormalities in segmental-wall motion and received a diagnosis of perioperative infarction. All eight had elevations of cardiac troponin I, and six had elevations of MB creatine kinase. Of the 100 patients without perioperative infarction detected by echocardiography, 19 had elevations of MB creatine kinase, and 1 had a slight elevation of cardiac troponin I.

CONCLUSIONS

The measurement of cardiac troponin I is a sensitive and specific method for the diagnosis of perioperative myocardial infarction. It avoids the high incidence of false diagnoses associated with the use of MB creatine kinase as a diagnostic marker.

Risberg retroperitoneal approach to the abdominal aorta

In a study of the best approach to the infrarenal abdominal aorta, 47 patients were compared retrospectively: 15 underwent a standard transperitoneal incision, 15 a retroperitoneal left flank incision and 17 a new modified lateral pararectus incision, the Risberg approach. Operating time, length of postoperative intubation and hospital stay, mortality rate, morbidity rate and cost were assessed. There was a significant reduction (P < 0.05) in mean(s.d.) operating time (141(21) versus 198(41) min), intraoperative cross-clamping time (74(13) versus 104(46) min) and postoperative intubation time (6.5(8.0) versus 13.3(7.3) h) associated with the Risberg retroperitoneal incision compared with the left flank retroperitoneal route. There was also a significant decrease (P < 0.02) in mean(s.d.) postoperative intubation time (6.5(8.0) versus 17.5(12.0) h), time after operation to discharge (11.0(2.4) versus 17.3(7.6) days) and hospital cost (4885(670) pounds versus 7732(580)) pounds associated with the Risberg incision compared with the transperitoneal approach. The Risberg incision gives better access to the infrarenal abdominal aorta while maintaining the advantages of other retroperitoneal approaches. This technique is recommended as the incision of choice for the retroperitoneal approach to the aorta.

Pararectus retroperitoneal radical nephrectomy

We describe a new pararectus retroperitoneal approach to the kidney, which allows easy identification and occlusion of the renal vessels before mobilization of the kidney. This approach potentially reduces morbidity, hospital stay and cost. The technique has been used in 4 cases of radical nephrectomy for tumor and in 1 for pyonephrosis.

Infrarenal abdominal aortic disease: a review of the retroperitoneal approach

Transabdominal exposure is the most widely used surgical approach to the infrarenal aorta. Over the last 30 years a number of surgeons have championed the retroperitoneal approach for repair of abdominal aortic aneurysms and aortoiliac occlusive disease using a variety of incisions. Several studies attest to the clinical superiority of this approach over the transabdominal route and recent evidence demonstrates reduced physiological disturbance with this technique. The retroperitoneal approach is suitable for all elective operations on the abdominal aorta, particularly in patients with high-risk aneurysms and in selected patients with symptomatic and ruptured aneurysms.

Epidural anesthesia as an adjunct to retroperitoneal aortic surgery

Recent developments in vascular surgery suggest that the retroperitoneal approach to the aorta and the use of epidural anesthesia for lower limb revascularization are associated with decreased morbidity and shorter hospital stays. By combining these principles, we sought to determine if retroperitoneal aortic surgery could be performed under epidural anesthesia and if this might be advantageous. Over a 16-month period, 57 patients underwent aortic surgery via the retroperitoneal (n = 33) or transperitoneal (n = 24) approach. In the former, epidural anesthesia was employed in 10 patients, general anesthesia in 3, and combined epidural anesthesia and general anesthesia in the remaining 20. In the transperitoneal group, general anesthesia was employed in 21 patients and combined epidural anesthesia and general anesthesia in 3. Both groups were similar in age and gender, but risk factors were predominant in the retroperitoneal group. With the exception of one death due to aspiration, there were no significant differences between the transperitoneal and retroperitoneal groups with respect to overall morbidity, pulmonary complications, and length of stay in the intensive care unit and hospital. Despite these findings, we favor the combination of epidural and general anesthesia for retroperitoneal aortic surgery. Morbidity was significantly decreased (p less than 0.05) in low-risk retroperitoneal patients when combined epidural anesthesia and general anesthesia were employed.