The relationship of endothelin-1 and inducible nitric oxide synthase at several stages of the anastomotic healing process.

AIM: The aim of this study was to investigate the interaction between the endothelin-1 (ET-1) and inducible NO synthase (iNOS) in anastomotic healing. METHODS: The expression of ET-1 and iNOS were investigated by immunohistochemistry in a rat end-to-end arterial anastomotic model. The aorta of 50 male Wistar rats was exposed, then transversely divided and re-anastomosed. The animals were sacrificed immediately after the operation (group A, control group), after 24 h (group B), on 7th postoperative day (group C), on 30th day (group D) and at 6 months (group E). Intima and media thickness and their ratio of the anastomotic segments in each group were calculated from computer digitized images of the individual sections. ET-1 and iNOS expression were measured on a semiquantitative scale ranging from 0 to 3. RESULTS: ET-1 was expressed from endothelial and smooth muscle cells (SMCs), while iNOs was expressed from SMCs and inflammatory cells. An intense expression of ET-1 was demonstrated mainly at 1 week and to a lesser degree at 1 month. Yet, at 6 months this expression was significantly weakened (P<0.001). In contrast, an intense iNOS expression was identified at 24 h, substantially regressing at statistical significant lower levels after 1 week (P<0.001). Bivariate correlation test showed a positive correlation between ET-1 and iNOS expression. CONCLUSION: ET-1 appears to play an important role in intimal thickening during anastomotic healing, especially in the late period of the process. Although there is a positive correlation between ET-1 and iNOS production, the activity of the latter is relatively limited after the first postanastomosis week.

Inguinal anastomotic aneurysm due to salmonellosis treated with orthotopic reconstruction.

Femoral anastomosis following either an aortofemoral or femoropopliteal bypass, is a common site for anastomotic aneurysms occurring with an incidence of 2% to 5%. Among the factors contributing to the pathogenesis of such aneurysms, graft infection should be considered as a major one. We report the case of a 74 years old woman with history of an aorto-femoral right and -iliac left bypass with a Dacron Y-prosthetic graft due to abdominal aneurysm. The patient presented with a painful, inflammatory, and pulsating mass in her right inguinal region. She was treated surgically with wide radical resection of infected tissues including the anastomotic aneurysm, and in situ bypass reconstruction using a Silver-Dacron graft. Cultures of inflamed wound tissue, graft, and stools were positive for Salmonella typhimurium. In the postoperative period the patient was submitted to subtotal colectomy due to colon cancer and later to an iliofemoral crossover-bypass from right to left due to acute ischaemia of the left limb. Her postoperative follow up has been insignificant. Infected femoral anastomotic aneurysms due to salmonellosis are a rarity. Although their treatment of choice consist in an extra-anatomic bypass, under specific conditions in situ reconstruction may be adopted as a feasible and effective surgical technique to treat these infected aneurysms.

Outcome of infrainguinal revascularization for critical limb ischemia in diabetics with end stage renal disease.

BACKGROUND: End stage renal disease [ESRD] and diabetes have a negative effect on outcome of arterial reconstructions, because they are associated with a vulnerability to infection, an infrageniculate arterial occlusive disease and an increased perioperative risk. The combination of both in critically ischemic patients is traditionally considered a great threat to their limb or life. The risk/benefit ratio of revascularization in this clinical setting is marginal and therefore the decision making is controversial. This study was undertaken to determine the results of arterial reconstruction in patients with end-stage renal disease and diabetes mellitus. PATIENTS AND METHODS: The outcome of 97 patients undergoing 121 arterial reconstructions due to lower limb threatening ischemia were reviewed. Primary and secondary patency rates as well as survival and limb salvage were estimated. RESULTS: Thirty-day operative mortality rate was 10.3%. At one month, one year and 2 year follow-up, the survival rate was 89.7%, 77.6% and 44.2% respectively. Limb salvage at 6 months was 85.6%, at 12 months 75.3% and at 2 years 56.3%. The primary and secondary patency was 92.4% and 93.2% at 6 months and 71.7% and 72.7% at 12 months, respectively. CONCLUSIONS: Diabeticpatients with ESRD attained an acceptable graft patency and limb salvage but they sustained higher perioperative mortality and morbidity and reduced survival.

Femoral anastomotic aneurysms in the modern era: a reappraisal of a continuing challenge.

AIM: Despite improvement in the operative technique and graft and suture material, femoral anastomotic aneurysms (FAAs) represent a continuing problem for patients undergoing lower extremity revascularization. The present retrospective study investigates the clinical presentation, the infection as a cause of FAAs, the interval between the original operation and the development of FAAs. It also evaluates the mortality and amputation rate of patients with FAAs. METHODS: We reviewed the records of 124 patients (thrombendarterectomy in 9, femoro-femoral bypass in 3 and axillofemoral bypass in 1). RESULTS: There were 13 infected and 14 recurrent FAAs. The overall mean time elapsing between the initial operation and the development of FAAs was 56.9 months (range 1-219). This interval was 62 months for the noninfected FAAs, while it was only 8 months for the infected FAAs. The mean time interval in which a recurrence of FAAs occurred was 39 months. The most common type of repair was an interposition prosthetic graft from the proximal prosthesis to the profunda femoral artery (100 cases). In the postoperative period local complications occurred in 21 (15.4%) cases and systemic in 7 (5.1%). The postoperative mortality was 3.7%. The overall survival at 1 year was 91.3% (standard error: +/-2.5%) and at 2 years 85.4% (standard error: +/-3.3%). Kaplan-Meier analysis showed a cumulative limb salvage of 94.2%, 93.3 % and 89.2% after 6 months, 1 and 2 years, respectively. A significant relationship was demonstrated between amputation and the following parameters: infected FAAs (Log rank test: 26.1, P-value <0.001), diabetes (Log-rank test: 12.9, P-value <0.01), peripheral arterial occlusive disease (Log-rank test: 3.1, P-value =0.08), and prior limb amputation (Log-rank test: 9.9, P-value <0.01). The mean time to amputation for the infected FAAs was 49.6 months (95% CI: 24.3-74.8), while for the noninfected it was 98.8 months (95% CI: 93.4-104.2). CONCLUSIONS: Complicated FAAs are still responsible for significant morbidity and mortality. Elective treatment produce the maximum benefit.

[Angioplasty of the distal anastomosis und runoff arteries of occluded infrainguinal bypasses]. / Die Angioplastie der distalen Anastomose und Run-off-Arterien bei verschlossenen infrainguinalen Bypässen.

BACKGROUND: We investigated the clinical results of transluminal angioplasty performed through infrainguinal bypass grafts for stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries in high risk patients and the influence of different parameters on limb salvage, primary and secondary patency rate. PATIENTS AND METHODS: Between January 2001 and March 2005 we performed 49 transluminal angioplasties on stenotic or occlusive lesions at the distal anastomosis and/or in the runoff arteries in 49 (16 female, 23 male, mean age 71.1 years) patients with occluded infrainguinal bypass. 20 angioplasties occurred in the runoff arteries, 5 at the distal anastomosis and 24 at both locations at a median of 11.3 months (range 2-85 months) after infrainguinal bypass grafting). 20 procedures were on popliteal artery above the knee, 21 below the knee and 8 on crural arteries. RESULTS: Kaplan-Meier analysis showed a cumulative limb salvage of 87.6 and 76.4 % after 6 months and two years, respectively. Patients with gangrenous lesions had a 5 times higher risk of amputation (Cox-regression model). Primary and secondary patency rates were at 6 months 85.1 and 91.1 % respectively and were at one year 73.3 and 78.8 % respectively. Patients with end stage renal disease were in 4 times hazard to primary occlusion and patients with gangrenous lesions 5 times to secondary occlusion (Cox-regression model). CONCLUSION: Even if the long-term results of angioplasty on stenotic or occluded lesions at the distal anastomosis and/or in the runoff arteries are inferior to the results of surgical revisions reported in literature, angioplasty in high risk patients with absence af a vein may be the first line alternative intervention for limb salvage.