Jean-Michel Cormier

High levels of portal TNF-α during abdominal aortic surgery in man

Abstract During shock or multiple organ dysfunction syndrome, translocation of bacteria and/or lipopolysaccharide (LPS) from the ischaemic gut might occur and could explain the excess of cytokine production detectable in plasma. To test this hypothesis, we studied a model of mild gut ischaemia due to bowel manipulation and aortic clamping in patients undergoing abdominal aortic surgery (n = 14). Per-operative levels of LPS and cytokines were measured before clamping and after reperfusion, and compared in systemic and portal blood. Systemic levels of LPS and cytokines were measured in a control group of patients undergoing internal carotid surgery (n = 7). Portal LPS was detectable (i.e., >12 pg/ml) in 36% of the patients undergoing aortic surgery after bowel manipulation, and in 71% after clamp release. Similar levels of LPS were observed in portal and systemic blood after clamp release. Circulating tumour necrosis factor alpha (TNF-α) was observed in all patients undergoing aortic surgery. Levels of portal TNF-α were higher than those in systemic blood after bowel manipulation as well as after reperfusion (P = 0.02 and 0.007, respectively). LPS was never detected in control patients and TNF-α was detectable in only two out of seven patients. Mean levels of IL-6 were similar in the two groups, with a peak on the day following surgery, confirming that circulating IL-6 is associated with any surgical procedures. Our data indicate that bowel manipulation, aortic clamping and reperfusion lead to similar levels of portal and systemic circulating LPS. High levels of portal TNF-α as compared to systemic ones, suggest that the gut-associated macrophages, activated by bowel manipulation, mild ischaemia, and/or translocated LPS, are a probable source of TNF-α.

Influence of surgery on in-vitro cytokine production by human monocytes.

Surgery leads to significant modulation of the immune system, in which cytokines play a major role. Circulating interleukin 6 (IL-6) and IL-1 have been reported following surgery whereas tumor necrosis factor alpha (TNF-alpha) is only found in gut ischemia-associated surgery. We have investigated the consequences of surgery on in-vitro cytokine production by human monocytes stimulated by lipopolysaccharide (LPS) and staphylococcal toxic shock syndrome toxin-1 (TSST-1). Comparisons were made between the responsiveness of cells obtained the day before (D-1), during (D0) and after (D1, D2, D3) surgery. Patients undergoing abdominal aortic surgery (N = 9), carotid surgery (N = 4) and spinal surgery (N = 4) have been studied. A significant decrease of TNF-alpha, IL-1 beta and IL-1 alpha production by monocytes prepared from blood samples taken during the surgery was noticed, whereas IL-6 production was not significantly modified. On D2 a significant increase of monocyte responsiveness was observed and levels of cytokine productions rose back to initial values by the end of the follow up. The diminished in-vitro cytokine production observed during surgery might be the consequence of the effects of anaesthetic drugs, whereas the enhancement observed on D2 might reflect the surgical stress, leading to in-vivo priming of circulating monocytes.

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.

Congenital Anomalies of the External Iliac Artery: Case Report and Review of the Literature

Routine arteriograms obtained during work-up for occlusive arterial disease of the lower limbs disclosed a rare congenital anomaly in a 47-year-old man. The common femoral artery arose directly from a pelvic artery which followed the normal course of the internal iliac artery. Congenital anomalies involving the external iliac artery can be classified into three groups: (1) anomalies of origin or course which are in fact anatomic curiosities; (2) hypoplasia or atresia coexisting with persistent sciatic artery; and, (3) isolated hypoplasia or atresia which can occasionally cause chronic ischemia of the lower limbs. The anomaly reported herein can be classified either as agenesia or abnormal course of the external iliac artery.

Direct Arteriovenous Fistula of the External Carotid Artery: Treatment with Detachable Balloon

Direct arteriovenous fistulas originating from the terminal branches of the external carotid artery constitute a rare form of facial vascular disorders. They are usually well tolerated and do not grow. Surgical removal or ligation of the fistula may be hazardous to the facial nerve or lead to aesthetic insult. Based on our experience in five cases treated successfully with detachable balloons, we propose this technique as an alternative to surgery.

Pelvic arteriovenous fistulas: Therapeutic strategy in five cases

Pelvic arteriovenous fistulas are rare. They may be defined as arteriovenous communications developing in the pelvis from the internal iliac artery, the origin of its posterior trunk or branches of its anterior trunk. Congenital arteriovenous malformations, more common in women, and posttraumatic arteriovenous fistulas are the two main etiological forms. Diagnostic problems include appreciation of visceral extension in arteriovenous malformations and precise localization of fistulas especially when they affect the internal iliac artery itself. Therapy is aimed at complete closure of arteriovenous communications using interventional radiologic methods or surgery. Although indications are difficult to assess, complete, one-stage therapy is preferable due to surgical difficulties following failed or incomplete radiological or surgical attempts.

Long-term results of aortoinnominate and aortocarotid polytetrafluoroethylene bypass grafting for atherosclerotic lesions

Between January 1978 and December 1986, 69 polytetrafluoroethylene bypass grafts on the ascending aorta were placed in 53 patients with atherosclerotic occlusive disease of the innominate and left common carotid arteries. Thirty-six patients had symptoms predominantly of amaurosis fugax, verebrobasilar ischemia, and upper limb ischemia. The remaining 17 patients had no symptoms but had severe hemodynamically significant occlusive disease. All operations were accomplished via median sternotomy. One patient died after surgery (operative mortality rate 1.9%), and one patient had minor postoperative neurologic deficit that partially improved on long-term follow-up. Patency of the reconstruction was routinely assessed by a Doppler device combining (1) a continuous wave Doppler and (2) real-time mechanical sector B-mode imaging with frequencies of 3.5 MHz and 7.5 MHz. There were two early asymptomatic occlusions; one was related to a technical error that was successfully revised and the other to low systemic perfusion. The mean follow-up time was 50.5 months. Two patients were lost to follow-up and a further six patients died, for a cumulative 5-year survival rate of 84.9%. One patient had only partial improvement in symptoms and one patient sustained a late postoperative neurologic deficit after internal carotid occlusion distal to a patent aortocarotid bypass. The remaining patients were free of symptoms. There were no infective complications. All the patients underwent late assessment by Doppler ultrasonography and B-mode scanning. One asymptomatic occlusion was thereby identified to be a result of diminished runoff. The overall secondary patency rate at 5 years was 96.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

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.