Jean-Marc Fichelle

Acute Colorectal Ischemia after Aortic Surgery: Pathophysiology and Prognostic Criteria

Acute colorectal ischemia is a rare though potentially lethal complication of aortic surgery. We reviewed our recent experience with 16 cases in order to analyze its causative and prognostic factors. The incidence was 2.8%, and the inferior mesenteric artery was occluded in all cases. All patients also had severe occlusive disease of at least two of the hypogastric or deep femoral arteries. Hypoperfusion due to arterial ligation, prosthetic occlusion or embolism was responsible in half the cases. Ischemia and perfusion due to aortic cross-clamping or perioperative hemorrhage were involved in the rest of the cases. Postoperative mortality was 31%. The mortality was lower for partial, nontransmural necrosis, and for elective operations. Recurrent intestinal ischemia, transmural necrosis, surgery for ruptured aneurysm, intestinal hemorrhage and pulmonary edema were associated with a higher mortality rate. All patients with anuria or extrarenal epuration and hepatic cytolysis died. Although reconstruction of the inferior mesenteric artery might lessen the incidence of postoperative colonic ischemia due to hypoperfusion, the role of oxygen free radicals should be investigated in humans, in order to afford colonic protection against the consequences of ischemia-reperfusion.

Polytetrafluoroethylene Bypass for Revascularization of the Atherosclerotic Internal Carotid Artery: Late Results

Between 1979 and 1986, 60 patients underwent a total of 62 revascularizations of the internal carotid artery with an expanded polytetrafluoroethylene (ePTFE) bypass. In 54 cases, the indication for surgery was the presence of extensive lesions in both the internal and common carotid arteries and, in 8 cases, a late complication of a previous surgical procedure. There were no early postoperative deaths (within 30 days). Three patients (5%) experienced postoperative neurologic complications. Two complications resolved completely whereas one left minimal residua. The bypasses remained patent in all three cases. All patients had early postoperative Doppler B-mode ultrasonography. Two early occlusions (3.2%) were disclosed but the patients remained symptom-free. Four neurologic complications were observed over long-term (average 23 months) follow-up. None were related to the operated carotid artery. There were no cases of infection or late occlusion. No hemodynamic or morphologic anomalies were observed on late follow-up ultrasound studies. These favorable results support the use of ePTFE as a reliable substitute when adequate autologous saphenous vein is not available for carotid bypass. Routine utilization might be indicated in cases of long bypasses, especially when it is necessary to implant the bypass on the ascending aorta, or when the proximal site of implantation is made on a thickened arterial wall.

Renal Artery Revascularization with Polytetrafluoroethylene Bypass Graft

Between January 1979 and December 1986, a total of 74 renal revascularizations were performed in 68 patients using the reinforced expanded polytetrafluoroethylene prosthetic graft. These 74 revascularizations represent 29% of 251 surgical renal revascularizations performed during the same period of time. Eight patients had a total of nine revascularizations in the emergency setting (group I) for ruptured suprarenal aneurysm or acute thrombosis of the renal arteries. Only one patient survived and six years later, his anatomic and functional results are satisfactory. Sixty-five revascularizations were performed electively in 60 patients (group II). This group consisted of 19 renal revascularizations alone, and 46 combined aortic and renal revascularizations. One patient died of respiratory complications two months after operation after his thoracoabdominal aneurysm was cured. Early repeat postoperative arteriography showed that six reconstructions had occluded (three major renal arteries, three polar arteries). One patient was lost to follow-up. The remaining patients were followed for a mean of 41 months. Follow-up arteriograms obtained during 1987 showed that there were two late occlusions and two distal anastomotic stenoses. Actuarial patency was 85 +/- 10% at 72 months. Polytetrafluoroethylene prosthetic grafts constitute a reliable material for renal revascularization and combined aortic and renal reconstruction in certain anatomic conditions.

Outcome of Infrainguinal Endovascular Revascularization Procedures for Limb-Threatening Ischemia

This report describes the results of 96 infrainguinal endovascular revascularization procedures performed in 86 patients with limb-threatening ischemia over a 3-year period. There were 41 women and 45 men (mean age 72.9 +/- 11.9 years) including 47 patients (51.1%) with diabetes and 13 (15.1%) with renal insufficiency. All patients had severe ischemia characterized by rest pain (18.8%), ulceration (12.5%), or gangrene (68.8%). Twelve procedures were carried out in association with conventional surgical reconstruction and in eight patients with mixed ulcers a venous procedure was performed during the same session. A total of 143 arterial lesions were treated including 61 occlusions (mean length 5.9 +/- 3.5 cm) and 82 stenoses (mean length 4.6 +/- 3 cm). The following techniques were used: transluminal angioplasty in 99 cases, laser in five cases, Rotablator in 24 cases, and aspiration thrombectomy in 15 cases. Nine patients (10.5%) died in the hospital. Initial failure was observed in 32 patients, of whom 18 underwent subsequent surgical revascularization and 14 required amputation of the extremity within 2 months. Analysis of variance was used to assess the following 12 risk factors for initial failure of endovascular revascularization: sex, age, diabetes, renal insufficiency, associated surgery, treatment of multiple lesions, artery treated, type of lesion, length of lesion, quality of runoff, use of an atherotome, and stent placement. Results showed a significant correlation between initial failure and both quality of runoff (12.9% in patients with two or more patent leg arteries vs. 36.5% in patients with one or fewer patent leg arteries; p < 0.05) and type of lesion (14.5% for stenosis vs. 45.9% for occlusion). Mean follow-up was 9.98 +/- 9.9 months and 4.7% of patients were lost. Restenosis was observed during follow-up of 16 of the 74 initially successful procedures. ANOVA was used to assess the same 12 risk factors for restenosis. Results showed a significant correlation between restenosis and both sex (10.8% in women vs. 32.4% in men; p < 0.05) and age (8% for patients > 80 years of age vs. 28.6% for patients < 80 years; p < 0.05). Primary patency, secondary patency and limb salvage rates calculated according to the actuarial method were 65%, 75%, and 84%, respectively, at 6 months and 47%, 67%, and 81%, respectively, at 1 year. Limb salvage rates for the endoluminal techniques used in this study were satisfactory, especially in elderly patients with either segmental lesions or contraindications for distal bypass.

Renal Revascularization in High-Risk Patients: The Role of Iliac Renal Bypass

Between 1984 and 1989, 29 iliac renal artery bypasses were performed in 29 patients (mean age 67.8 years) with severe renovascular disease due to atheroma. The indication for renal artery reconstruction was hypertension in all patients, which was associated with kidney failure in 16 cases. In six cases, reconstruction was performed after failure or complications of percutaneous transluminal angioplasty. The bypass was constructed with polytetrafluoroethylene in 24 cases (83%) and vein graft in five cases (17%). There was no postoperative mortality. All bypasses were found to be patent on duplex scanning or digital subtraction arteriograms. One patient was lost to follow-up. Mean follow-up was 23.2 months. One patient died of acute kidney failure, probably related to occlusion of the bypass. Hypertension improved in 22 cases (79%), was cured in two cases (7%), and remained unchanged in four (14%). Renal function remained unchanged in six cases (40%) and improved in nine (60%). Iliac-to-renal artery bypass seems to be the surgical renal revascularization modality best adapted to high-risk patients or those who have severe atheroma. Additionally, this technique enables rapid treatment of failures or complications of percutaneous transluminal angioplasty of the renal artery.

Aorto-femoral bypass with polytetrafluoroethylene prostheses preliminary results in 363 cases

From October 1977 to October 1982, 363 unilateral aorto-femoral bypasses using polytetrafluoroethylene (PTFE) prostheses were performed for predominantly unilateral aorto-iliac disease. The distal anastomosis was extended into the deep femoral artery in 57% of the patients. The postoperative mortality was 0.5%. The actuarial patency rate after 6 years was 87% in patients with claudication and 77% in those with critical ischemia. No false aneurysm developed. Thrombosis of the prosthesis was due to progression of distal disease, intimal hyperplasia and postural extrinsic compression. The latter seems to be characteristic of PTFE prostheses and can be treated by thrombectomy. In 21 cases a cross-over femoro-femoral bypass was done during the follow-up period because of contralateral progression of disease.

Infections of aortobifemoral prostheses at level of the Scarpa's triangle--place of local treatments.

Postoperative infection is the most serious complication in vascular surgery. It compromises the concerned arterial restoration and the functional and vital prognosis are called into question. Infectious complications are rare and represent 1 to 3% of the aortobifemoral prostheses. Usually, the postoperative vascular infections are classified into 3 grades according to the depth and extension of the septic process (I) Grade I concerns the cutaneous infections Grade II concerns the subcutaneous cellular tissue infections but not the restored arterial axis. Grade Ill concerns the infections of the prosthetic graft and/or – by extension, the arterial tree. This clinical classification is of great importance both practical and theoretical, from one hand because the patients presenting a grade I infection are generally cured after an adapted local treatment, and from the other hand, grade Ill infections pose difficult therapeutic, medical and surgical problems. At present, facing an infection of an aortobifemoral prosthesis, several therapeutic options are possible (2-4). These are

Aorto-femoral bypass with polytetrafluoroethylene prostheses: preliminary results in 363 cases@@@Pontajes aorto-femorales en polytetrafluoroethileno: resultados preliminares de 363 pontajes

From October 1977 to October 1982, 363 unllateral aorto-fermoral bypasses using polytetrafluoroethylene (PTFE) prostheses were performed for predominantly unllateral aorto-llac disease. The distal anastomosis was extended into the deep femoral artery in 57% of the patients. The postoperative mortallty was 0.5%. The actuarial patency rate after 6 years was 87% in patients with claudication and 77% in those with critical ischemia. No false aneurysm developed. Thrombosis of the prosthesis was due to progression of distal disease, intimal hyperplasia and postural extrinsic compression. The latter seems to be characteristic of PTFE prostheses and can be treated by thrombectomy. In 21 cases a cross-over femoro-femoral bypass was done during the follow-up period because of contralateral progression of disease.ResumenDe Octubre de 1979 a Octubre de 1982, han sido realizados 363 pontajes aorto-femorales unilaterales en polytetrafluoroethileno (PTFE). Estos pacientes han presentado lesiones aorto-ilíacas de predominio unilateral. La anastomosis distal ha sido realizada sobre la arteria femoral profunda en el 57% de los pacientes. La mortalidad post-operatoria es de 0,5%. La permeabilidad a 6 años es de 87%, en los pacientes operados por claudicacío intermitente y de 77% para los pacientes operados por isquémia aguda. Ningún aneurisma anastomótico ha sido observado. Las occlusiones tardías de estos pontajes son debidas a 3 causas: la deterioración del lecho vascular distal, la hiperplasia intimal yuxta anastómotica y un mecanismo postural que parece muy específico en los pontajes en PTFE, que puede ser tratado por simple trombectomía. En el curso del seguimiento, 21 pacientes han recibido un pontaje femoro-femoral complementario, en razón de la evolutividad de las lesiones contralaterales.