Laparoscopic-assisted abdominal aortic aneurysmectomy.

PURPOSE: The technical elements and early results of laparoscopic-assisted abdominal aortic aneurysmectomy are described. METHODS: From February 1997 to May 1999, 60 patients underwent elective laparoscopic surgery for infrarenal abdominal aortic aneurysm. Patients ranged in age from 53 to 87 years (mean age, 70.6 years). The mean aneurysm size was 5.7 cm (range, 4.4-8.0 cm). All patients underwent aortography and computed tomography scanning preoperatively. Patients were not deemed candidates for the procedure when visceral arterial abnormalities requiring surgical treatment were present or an aortic aneurysm neck shorter than 0.5 cm was found. A risk-stratification system was used as a means of quantitating risk factors and excluding high-risk patients. Aortic reconstruction was performed with retroperitoneal laparoscopy, with the patient in a modified right lateral decubitus position. An Endo TA 30 and an Endo TA 60 laparoscopic staplers (US Surgical, Norwalk, Conn) were used in occluding the common iliac arteries and aneurysm sac. Laparoscopic hemoclips were used as a means of occluding the lumbar arteries and other branches of the aneurysm sac. An aortobifemoral or aortobi-iliac bypass grafting procedure was performed by means of the laparoscope to position the graft and visualize the end-to-end aorta-to-graft anastomosis, with distal anastomoses performed through counter incisions. RESULTS: Three patients died within 30 days of surgery (mortality rate, 5.0%). Complications included left ureteral injury (1), postoperative myocardial infarction (1), ileofemoral deep venous thrombosis (1), acute renal failure (2), colon ischemia (1), and infected graft limb requiring revision (1). The mean operative time was 7.7 hours, and the mean aortic cross-clamping time was 112 minutes. Compared with a contemporary consecutive series of 100 patients undergoing open transabdominal or retroperitoneal aneurysmectomy performed by the same group of surgeons, the laparoscopic patients had decreased length of stays in the intensive care unit and the hospital, with less need for ventilator support, earlier resumption of a regular diet, and an earlier return to normal activity. At the follow-up examinations, all bypass grafts were patent. CONCLUSION: Laparoscopic-assisted aneurysmectomy is safe and effective and can be performed with good results. The longer operation time required is well tolerated in patients who are at good and moderate risk. Prior training in laparoscopic aortic surgery is necessary for surgeons to obtain the required level of expertise needed to perform these procedures. With these caveats, the results of our study suggest that laparoscopic-assisted aortic aneurysmectomy is appropriate for moderate-to-good risk (American Society of Anesthesiologists class of III or lower) operative candidates meeting standard criteria for aneurysm resection in whom preoperative computed tomography scan and biplane arteriography demonstrate a proximal aneurysm neck of 0.5 cm or larger and no need for visceral or internal iliac artery reconstruction. A randomized trial would be required to confirm the benefits of this procedure over open aneurysmectomy.

Lung matrix incorporation of plasma fibronectin reduces vascular permeability in postsurgical bacteremia.

Plasma fibronectin (pFN) can incorporate into the lung extracellular matrix (ECM) as well as enhance hepatic cell phagocytic removal of bloodborne microparticulate debris that can contribute to lung vascular injury. Treatment of human pFN (hFN) with N-ethylmaleimide (NEM) blocks its ECM incorporation but not its ability to augment phagocytosis. Using hFN purified from fresh human plasma cryoprecipitate, we compared the effect of NEM-treated hFN versus normal hFN on lung transvascular protein clearance (TVPC) in postoperative bacteremic sheep to determine whether the ability of hFN to attenuate the increase in lung endothelial permeability required its ECM incorporation. Sheep with lung lymph fistulas were infused with a sublethal dose of Pseudomonas aeruginosa (5 x 10(8)) 48 h after surgery. In the first study, sheep received either FN-rich human cryoprecipitate, FN-deficient cryoprecipitate, FN purified from cryoprecipitate (hFN), FN-deficient cryoprecipitate reconstituted with purified hFN, or the sterile saline diluent. In the second study, sheep received either 200 mg of purified hFN (group I), 200 mg of NEM-treated hFN (group II), or the saline diluent (group III). In the first study, the increase in TVPC after bacterial challenge was attenuated by FN-rich cryoprecipitate, hFN, or reconstituted FN-deficient cryoprecipitate (P < 0.05) but not by saline and FN-deficient cryoprecipitate. In the second study, TVPC increased by 2 h (P < 0.05) and peaked over 4-8 h (P < 0.05) at 380-420% above baseline in postoperative bacteremic sheep given the diluent (group III). In contrast, intravenous infusion of hFN, but not of NEM-treated hFN, significantly (P < 0.05) attenuated this increase of lung protein clearance. Thus the ability for the intravenously infused purified pFN to attenuate the increase in lung endothelial protein permeability in sheep during postsurgical bacteremia appears to require its ECM incorporation into the interstitial ECM of the lung.

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.

Alternative approach for management of infected aortic grafts.

PURPOSE: Prosthetic infection after aortic reconstructive surgery historically has been treated with extraanatomical bypass, graft excision, and aortic stump closure, but at the cost of substantial mortality and amputation rates. Alternatives to this strategy include in situ prosthetic replacement in the infected area, as well as autogenous reconstructions. Inherent to all of these procedures, however, is either the creation of an aortic stump, which carries a significant risk of subsequent blowout, or the placement of a bypass conduit in the infected field, thereby maintaining the potential for subsequent infectious complications. To avoid such problems, we have used retroperitoneal in-line aortic bypass with polytetrafluoroethylene through dean tissue planes. METHODS: Since 1987 we have treated 16 graft infections in this manner. The surgical approach consisted of obtaining retroperitoneal proximal aortic control outside of the infected field (above or below the renal arteries), followed by infrarenal division and oversewing of the distal aorta. A polytetrafluoroethylene bifurcated graft was then sewn to the proximal aorta and tunnelled through the psoas sheath laterally to the profunda femoris artery on the ipsilateral side and via the space of Retzius to the contralateral appropriate femoral vessel, so as to avoid any contact with the infected areas. After the closure of the wounds, a plastic barrier was placed over all incisions and the patient was placed supine. The old infected graft was removed transperitoneally. Extensive cultures were taken at various sites to demonstrate no cross-contamination. RESULTS: All patients were followed-up clinically and with tagged white cell scans at 6-month intervals. There were no immediate postoperative deaths and no amputations. One patient had a myocardial infarction and died at 5 months, and a second patient died at 2 months. Of the remaining 14 patients, none had recurrent sepsis and all have had negative Indium-labeled white cell scans in follow-up. Eleven (78%) are still alive, with a mean follow-up of 32 months (range, 20 to 106 months). CONCLUSIONS: In-line aortic bypass for treatment of aortic graft infections yields excellent results and has become our treatment of choice in dealing with this difficult problem.

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.

Delayed rupture of aortic aneurysms following endovascular stent grafting.

BACKGROUND: Deployment of transfemoral, endovascular stent grafts for treatment of abdominal aortic aneurysms is appealing for several reasons: avoidance of abdominal incision, lack of aortic cross-clamping, potential for regional anesthesia, and shortened hospital stay. Concerns remain, however, regarding the ability of these devices to completely exclude the aneurysm and prevent aneurysm rupture and the long-term integrity of the device. The availability of endografts and the likely development of percutaneous devices have also raised the delicate issue of personnel training for patient selection, endograft implantation, and postoperative follow-up. PATIENTS AND METHODS: The cases of 2 patients are reported in which Dacron endovascular grafts, anchored proximally and distally by Palmaz stents, were deployed for treatment of infrarenal abdominal aortic aneurysms. RESULTS: In a patient with and absent distal cuff, choosing this procedure represented a clear error in patient selection. The endograft failed to reach the aortic bifurcation and the aneurysm ruptured, with the death of the patient 4 months postimplantation. In a patient with anatomy suitable for endograft placement, a perigraft leak persisted at the distal anastomosis following device placement. The aneurysm ruptured 14 days postprocedure. Although the patient survived emergent aneurysm repair, he developed acute renal failure. CONCLUSION: Careful preoperative assessment of aortic anatomy is crucial in selection of patients for transfemoral endovascular graft placement. Lack of a distal cuff of at least 1 cm precludes tube graft implantation. Patients with a perigraft leak are not protected by the endograft from aneurysm rupture. Vascular surgeons must be involved in the preoperative evaluation of these patients and are the only specialty group who can provide the prerequisite care in evaluation and management of postoperative complications.