A prospective randomized study comparing exclusion technique and endoaneurysmorrhaphy for treatment of infrarenal aortic aneurysm

Endovascular Solution to Endoleak Phenomenon After Open Repair of Abdominal Aortic Aneurysm

Endovascular aneurysm repair (EVAR) has quickly outpaced open treatment of infrarenal abdominal aortic aneurysm (AAA) and iliac artery aneurysms, relegating most open AAA repair for either young patients with long life expectancy or patients with extreme anatomic constraints. Typically, open repair involves opening the aneurysm sac with suture ligation of back-bleeding vessels. However, in situations where an aortobifemoral repair is performed, proximal and distal ligation can be performed leaving behind a "remnant" aorta and iliac arteries. Usually, major palpable vessels are ligated and small lumbars spontaneously thrombose. However, failure of this to occur can lead to a rare situation in which there is persistent filling of a remnant aorta and aneurysm sac leading to a situation similar to a type II endoleak after EVAR. Typically, this leak has been repaired by open ligation. We present a technique for endovascular coiling and thrombin injection to correct a "type II endoleak" from a back-bleeding lumbar artery after open aortoiliac and femoral aneurysm repair.

Laparoscopic Aortic Aneurysm Resection

Purpose:

To describe a laparoscopic technique for resection of infrarenal abdominal aortic aneurysms (AAAs).

Methods:

The operation is based on the principle of retroperitoneal reinforced staple exclusion of the aneurysm sac with aortobifemoral or aortoiliac bypass using gas and gasless laparoscopic techniques. Patients were eligible for this procedure if their infrarenal AAAs (with or without iliac artery involvement) were considered appropriate for surgical resection; however, renal or other visceral arterial stenoses, aneurysmal disease requiring surgical treatment, and/or aneurysms of the hypogastric arteries excluded patients from laparoscopic AAA resection.

Results:

Of 31 candidates for this procedure, 9 were excluded owing to high surgical risk. Twenty-two patients (16 males; age range 62 to 88 years) were deemed appropriate for the laparoscopic procedure. Maximum aneurysm diameter ranged from 4.0 to 8.0 cm. The operation was completed successfully in 20 (91%) patients. Two (9%) deaths in high-risk patients admitted early to the study occurred within 30 days of surgery. The only major complication was an injured ureter, for which a nephrectomy was performed. Comparison to a historical cohort of conventionally treated patients showed that the study group needed less ventilator support, had shorter intensive care and hospital stays, and resumed diet earlier despite relatively prolonged anesthesia and aortic clamping times.

Conclusions:

The laparoscopic approach to infrarenal AAAs appears feasible, with several potential advantages in low- and moderate-risk patients. Once the technique is optimized, randomized prospective studies will be needed to verify the apparent benefits demonstrated by these initial patients.

Endovascular treatment of late "endoleak" following open surgical repair using bypass and exclusion aneurysm repair

BACKGROUND

We sought to present endovascular management options of persistent or recurrent aneurysm sac flow ("endoleak") after operative retroperitoneal exclusion of infrarenal abdominal aortic aneurysm (AAA).

METHODS

Recurrent or persistent aneurysm perfusion was diagnosed in three patients primarily treated with aneurysm exclusion and bypass. The medical history, course of disease, and surgical management of these patients were reviewed.

RESULTS

Three patients primarily treated for infrarenal AAA by division of the aorta with suture closure of the proximal aneurysm end, ligation of the outflow vessels, and bypass of the excluded aortoiliac segment presented with persistent or recurrent AAA sac perfusion and growth. The feeding vessels were the iliac arteries in all cases. Endovascular repair using coil embolization and/or deployment of an occluder or stent-graft was successful in all patients with a follow-up of 42, 36, and 30, months respectively.

CONCLUSION

Open AAA repair using the exclusion and bypass technique is associated with the risk of persistent perfusion or reperfusion of the aneurysm sac, which is similar to an endoleak after endovascular aortic aneurysm exclusion. Endovascular therapy should be considered as first-choice treatment when feasible.

Minimally invasive retroperitoneal approach for the treatment of infrarenal aortic disease

PURPOSE

In order to decrease complications and improve postoperative recovery, we have developed a minimally invasive retroperitoneal approach (MIRPA) for the treatment of infrarenal aortic disease. This study was carried out to define the limitations and applicability of this technique in the treatment of aortoiliac occlusive disease (AIOD) and abdominal aortic aneurysms (AAAs).

METHODS

From November 2000 to February 2004, 150 patients with AAA (n = 130) or AIOD (n = 20) were prospectively included in the study. The procedure consisted in a standard aneurysmorrhaphy or bypass procedure performed through a video assisted left minilombotomy.The main outcomes measured were mortality, complications, operative time, aortic cross-clamp time, time to solid diet, and length of intensive care unit and hospital stay.

RESULTS

Operative mortality was 0.7 %. Nonfatal postoperative complications occurred in 12 patients (8%). Conversion to a standard procedure was necessary in 3 patients. Mean operative time was 207 +/- 57 minutes (AAA) and 224 +/- 55 minutes (AIOD). Mean aortic cross-clamp time was 76 +/- 26 minutes (AAA) and 48 +/- 21 minutes (AIOD). Median resumption of regular diet was 2 days. Median length of stay in the intensive care unit was 1 day and in the hospital 8 days.

CONCLUSION

Our results suggest that MIRPA is a safe and effective minimally invasive procedure in the treatment of infrarenal aortic disease.

Modeling endoleaks and collateral reperfusion following endovascular AAA exclusion

PURPOSE

To investigate the effect on intrasac pressure of stent-graft deployment within a life-size silicone rubber model of an abdominal aortic aneurysm (AAA) maintained under physiological conditions of pressure and flow.

METHODS

A commercial bifurcated device with the polyester fabric preclotted with gelatin was deployed in the AAA model. A pump system generated physiological flow. Mean and pulse aortic and intrasac pressures were measured simultaneously using pressure transducers. To simulate a type I endoleak, plastic tubing was placed between the aortic wall and the stent-graft at the proximal anchoring site. Type II endoleak was simulated by means of side branches with set inflow and outflow pressures and perfusion rates. Type IV endoleak was replicated by removal of gelatin from the graft fabric.

RESULTS

With no endoleak, the coated graft reduced the mean and pulse sac pressures to negligible values. When a type I endoleak was present, mean sac pressure reached a value similar to mean aortic pressure. When net flow through the sac due to a type II endoleak was present, mean sac pressure was a function of the inlet pressure, while pulse pressure in the sac was dependent on both inlet and outlet pressures. As perfusion rates increased, both mean and pulse sac pressures decreased. When there was no outflow, mean sac pressure was similar to mean aortic pressure. In the presence of both type I and type II endoleaks, mean sac pressure reached mean aortic pressure when the net perfusion rate was low.

CONCLUSIONS

In vitro studies are useful in gaining an understanding of the impact of different types of endoleaks, in isolation and in combination, on intrasac pressure after aortic stent-graft deployment.

Pressure measurements in closed aneurysmal sac during abdominal aortic aneurysm resection

PURPOSE

This study determined the relationship between closed aneurysmal sac pressure (ASP) and mean blood pressure (BP) during open abdominal aortic aneurysm (AAA) resection and evaluated the contribution of inferior mesenteric and lumbar artery blood flow to ASP after proximal and distal clamping.

METHODS

We measured ASP after proximal and distal clamping by placing an 18-gauge needle connected to a BP transducer into the excluded aneurysmal sac in 25 consecutive patients from April 1999 to August 2000. Simultaneous measurement of the mean systemic BP was also recorded. The ratio of ASP to mean BP in relation to the number of actively bleeding lumbar arteries (N-LA), diameter of the AAA (D-Cm), and volume of the thrombus in the AAA (Vol-TA) were recorded.

RESULTS

The mean ASP was 43.32 +/- 15.19 mm Hg, with an ASP to mean BP ratio of 0.47 +/- 0.15. The N-LA in the closed aneurysmal sac ranged from 0 to 6 (mean, 3.4 +/- 1.78). The D-Cm as determined by means of computed tomography (CT) scan of the aorta ranged from 5 to 8 cm in its largest anteroposterior/transverse diameter. The average Vol-TA was 6.15 +/- 4.49 mL. Inferior mesenteric artery blood flow contributed to ASP in three patients (12%). There was no correlation between ASP to mean BP ratios and the N-LA (P =.127), D-Cm (P =.882), or Vol-TA (P =.252).

CONCLUSION

Closed ASP and ASP ratios are highly variable and do not correlate with N-LA, D-Cm, or the Vol-TA.

Abdominal aortic aneurysm repair

Newer, minimally invasive catheter-based endovascular technology utilizing stent grafts are currently being evaluated for abdominal aortic aneurysm (AAA) repair. A retrospective review of all (3 years) consecutive, non-ruptured elective AAA repairs was undertaken to document the results of AAA surgical repair in a modern cohort of patients to allow a contemporary comparison with the evolving endoluminal data. One hundred twenty-one AAAs were identified in a male veteran population. Mean age was 68.5 +/-7.7 years. Medical history review showed hypertension in 55%, heart disease in 73.5%, peripheral vascular disease in 21%, stroke and transient ischemic attacks in 22%, diabetes mellitus in 7%, renal insufficiency in 10%, and smoking history in 80%. The AAA size was documented with ultrasound (5.2 +/-1.3 cm, n=40) and computed tomography (5.6 +/-1.3 cm, n=100). Fifty-nine percent had angiography. Intraoperative end points included an operative time of 165 +/-6.3 minutes from incision to dressing placement. A Dacron tube graft was used in 78%, the remaining were Dacron bifurcated grafts. A suprarenal clamp was used in 8% for proximal aortic control with juxtarenal aneurysms. A pulmonary-artery catheter was placed in 69%. A transverse incision was used in 69% of patients and a midline incision was used in the rest. Estimated blood loss was 1505 +/-103 mL; cell saver blood returned 754 +/-53 mL; crystalloid/Hespan 4771 +/-176 mL; banked packed red blood cells 0.75 +/-0.11 U. Time to extubation was, in the operating room (78.5%), on the day of the operation (5.0%), postoperative day (POD) 1 (12.4%), POD2 (1.7%), POD3 (0.8%), and one case was performed with epidural anesthesia only. Postoperative end points included a 30-day mortality rate of 1.6% (two patients). Postoperative morbidity included wound dehiscence 0.8%; sepsis, urinary tract infection, wound infection, leg ischemia, ischemic colitis, and stroke each had an incidence of 1.6%; myocardial infarction, congestive heart failure, pneumonia, re-operation for suspected bleeding, and ileus or bowel obstruction occurred with an incidence of 3.3%. No significant increase in serum creatinine levels was noted. Time to enteral fluids/nutrition was 3.5 +/-0.08 days. Patients were out of bed to a chair or walking by 1.3 +/-0.06 days postoperatively. The length of stay in the intensive care unit (ICU) was 2.0 +/-0.12 days and postoperative hospital stay was 6.6 +/- 0.33 days. Transfusion requirement for the hospital stay was 1.6 +/-0.2 U per patient. This review highlights a cohort of male veteran patients with significant cardiac co-morbidity who have undergone repair with a conventional open technique and low mortality and morbidity rates. This group had rapid extubation, time to oral intake, and ambulation. In addition, ICU and hospital stays were relatively short.

Repair of large abdominal aortic aneurysm should be performed early after coronary artery bypass surgery

PURPOSE

The surgical repair (coronary artery bypass grafting [CABG]) of symptomatic coronary artery disease (CAD) in patients with co-existent large abdominal aortic aneurysm (AAA) may result in an increased rate of AAA rupture after operation. Simultaneous CABG/AAA repair has been recommended by some surgeons, but with a somewhat higher mortality rate than staged repair. We reviewed the outcome of staged AAA repair that was performed early after CABG in patients with symptomatic coronary disease and AAA.

METHODS

The records of all the patients with symptomatic CAD that required CABG with large AAA (greater than 5 cm) were reviewed. In most patients, CABG was performed first, followed by AAA repair within 2 weeks. Patient demographics, severity of coronary disease, AAA size, interprocedure duration, and perioperative morbidity and mortality rates were examined.

RESULTS

Between 1991 and 1998, 1105 AAA repairs were performed. Within this group, 30 patients with AAA underwent CABG for symptomatic CAD. Mean AAA size was 6.6 cm (range, 5.0-10.0 cm). The median interprocedure interval between CABG and AAA repair was 11.5 days. There was no in-hospital AAA rupture during this interval. The patient group was comprised of 24 men and 6 women with a mean age of 71 years. There was no operative death after such staged AAA repair, and nonfatal complications occurred in seven patients (23%). During this period, seven patients had AAA rupture when they were sent home after CABG for recovery and intended AAA repair at a later date.

CONCLUSION

Staged elective AAA repair may be performed safely and effectively after CABG. Performance of these procedures with a short interprocedure interval may be preferable to the higher complication rate observed after combined procedures.

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.

Minimal incision abdominal aortic aneurysm repair

PURPOSE

The use of a limited incision for abdominal aortic aneurysm (AAA) repair was evaluated, and its outcome was analyzed in comparison to laparoscopic-assisted and standard open repair.

METHODS

Eleven patients who had an AAA that required a tube graft underwent minimal incision (MINI) repair. The procedure consisted of a standard endoaneurysmorrhaphy performed through an 8- to 10-cm minilaparotomy. Clinical characteristics, in-hospital outcomes, and total in-hospital charges for this procedure were then compared with those of comparative groups of patients who had undergone repair of AAA by means of a laparoscopic-assisted (LAP) approach or a standard open (OPEN) technique.

RESULTS

MINI repair was successfully completed in all 11 patients. Patients in the three groups were comparable for age, sex, risk factors, and aortic dimensions. The mean values for operative time, blood loss, length of hospital stay, and total hospital charges for the three comparison groups were: 129. 7 minutes (MINI) vs. 244.8 minutes (LAP)*, 209.9 minutes (OPEN)*; 522.7 mL (MINI) vs. 1214.7 mL (LAP), 1795.8 mL (OPEN)*; 5.18 days (MINI) vs. 18.7 days (LAP), 17.4 days (OPEN); $22,692 (MINI) vs. $59, 922 (LAP)*, $62,324 (OPEN)* (*P <.05). Local complications occurred in 18.2% of patients who underwent MINI repair, 23.5% of patients who underwent LAP repair, and 29.7% of patients who underwent OPEN repair (P = not significant). Patients undergoing minilaparotomy demonstrated decreased compromise of gastrointestinal function, with a decreased need for postoperative fluid resuscitation (6799.7 mL [MINI], 7781.8 mL [LAP] vs. 11061.1 mL [OPEN]*) and shortened nasogastric tube decompression (1.6 days [MINI], 1.5 days [LAP] vs. 4.1 days [OPEN]*; *P <.05).

CONCLUSION

MINI repair is a technically feasible technique that combines the benefits of minimally invasive surgery with those of conventional open repair with few, if any disadvantages. Facility of the procedure, combined with the potential cost benefits, encourages further study for consideration of this technique as a viable alternative for the management of AAAs.

Laparoscopic aortic aneurysm resection

PURPOSE

To describe a laparoscopic technique for resection of infrarenal abdominal aortic aneurysms (AAAs).

METHODS

The operation is based on the principle of retroperitoneal reinforced staple exclusion of the aneurysm sac with aortobifemoral or aortoiliac bypass using gas and gasless laparoscopic techniques. Patients were eligible for this procedure if their infrarenal AAAs (with or without iliac artery involvement) were considered appropriate for surgical resection; however, renal or other visceral arterial stenoses, aneurysmal disease requiring surgical treatment, and/or aneurysms of the hypogastric arteries excluded patients from laparoscopic AAA resection.

RESULTS

Of 31 candidates for this procedure, 9 were excluded owing to high surgical risk. Twenty-two patients (16 males; age range 62 to 88 years) were deemed appropriate for the laparoscopic procedure. Maximum aneurysm diameter ranged from 4.0 to 8.0 cm. The operation was completed successfully in 20 (91%) patients. Two (9%) deaths in high-risk patients admitted early to the study occurred within 30 days of surgery. The only major complication was an injured ureter, for which a nephrectomy was performed. Comparison to a historical cohort of conventionally treated patients showed that the study group needed less ventilator support, had shorter intensive care and hospital stays, and resumed diet earlier despite relatively prolonged anesthesia and aortic clamping times.

CONCLUSIONS

The laparoscopic approach to infrarenal AAAs appears feasible, with several potential advantages in low- and moderate-risk patients. Once the technique is optimized, randomized prospective studies will be needed to verify the apparent benefits demonstrated by these initial patients.

Initial experience with endovascular aneurysm repair: comparison of early results with outcome of conventional open repair

PURPOSE

To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA.

METHODS

Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months.

RESULTS

Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture.

CONCLUSIONS

Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk.