Background and aims: Radiation therapy of abdominal and pelvic solid tumours results in late intestinal toxicity of a severe nature in approximately 5%of cases. These manifestations may include ischaemia and stricture...Background and aims: Radiation therapy of abdominal and pelvic solid tumours results in late intestinal toxicity of a severe nature in approximately 5%of cases. These manifestations may include ischaemia and stricture formation,which may present as “webs". These webs are likely to play a role in the pathogenesis of recurrent bowel obstruction. The mechanisms of microvascular injury to the bowel in the setting of radiation have not been defined. We hypothesised that microvascular dysfunction with impaired vasodilation to acetylcholine (Ach) would be a n acquired pathophysiological abnormality in radiation and “web" formation. Met hods: A 40 year old patient treated with radiation, two years previously, for an anal squamous cell cancer presented with recurrent small bowel obstruction. “W ebs" in the distal ileum were detected using wireless capsule endoscopy, after s mall bowel barium radiographs failed to demonstrate a lesion. Following resectio n, freshly isolated 50-150 μmdiameter arterioles from the “web" and adjacent normal calibre bowel were analysed with histology and microvessel physiological studies. Results: After constriction (30-50%) with endothelin, dilation to gra ded doses of Ach (10-9-10-4 M) was observed in vessels dissected from the str icture and the adjacent normal calibre area. Ach dilation was reduced in vessels from “web" (mean diameter 7 (2)%; n = 3, p < 0.01) compared with the adjacent unaffected bowel (mean diameter 85 (5)%). Dihydroethidine and dichlorofluoresc ein diacetate intravital staining demonstrated increased reactive oxygen species production in microvessels from “web" compared with adjacent normal calibre bo wel. Histology from the structured bowel demonstrated narrowing of the arterial lumen due to intimal and muscularis propria fibrosis, with endothelial preservat ion. Conclusions: External radiation is associated with acquired microvascular e ndothelial dysfunction and “web" formation in the small bowel.展开更多
Objective. To review our preliminary experience and evaluate our early results of a combined intraoperative iliac angioplasty and stenting with infrainguinal revascularization in multilevel atherosclerotic occlusive d...Objective. To review our preliminary experience and evaluate our early results of a combined intraoperative iliac angioplasty and stenting with infrainguinal revascularization in multilevel atherosclerotic occlusive disease. Methods. From July 1999 to April 2000, intraoperative iliac angioplasty and stenting combined with simultaneous femoro- popliteal bypass were performed on 12 lower extremities of 10 patients suffering from multilevel atherosclerotic occlusive disease. There were 8 men and 2 women, average 72 years. The indications for procedures included disabling claudication in 3 and rest pain in 7 patients. Results. Eleven iliac angioplasty and stent procedures combined with simultaneous 9 femoro- popliteal bypass and 3 femoro- femoral- popliteal bypass were performed in 12 limbs of 10 patients. Angioplasty and stent placement was technically successful in all patients. One contralateral femoral- popliteal bypass was failure after femorofemoral- popliteal bypass. There were no additional instances of procedural or postoperative morbidity or mortali- ty. Mean follow- up was 5 months (range 1～ 10 months). During the follow- up period, one femoro- infrapopliteal graft became occluded after 7 months and above- knee amputation was required. The cumulative primary patency rate of stented iliac arteries, femoro- femoral bypass grafts and femoro- popliteal bypass grafts were 100％ (11/11), 100％ (3/3) and 90.9％ (10/11) in the follow- up period, respectively. The amputation rate was 8.3％ (1/12). Conclusions. Intraoperative iliac artery PTA and stent placement can be safely and effectively performed simultaneously with infrainguinal revascularization for multilevel atherosclerotic occlusive disease by skilled vascular surgeon, using a portable C arm fluoroscopy in the operating room. Furthermore, iliac artery PTA and stenting was valuable adjunct to distal bypass either to improve inflow and outflow, or to reduce the extent of traditional surgical intervention, and also, any angioplasty and stenting- related complications can be immediately corrected as well.展开更多
文摘Background and aims: Radiation therapy of abdominal and pelvic solid tumours results in late intestinal toxicity of a severe nature in approximately 5%of cases. These manifestations may include ischaemia and stricture formation,which may present as “webs". These webs are likely to play a role in the pathogenesis of recurrent bowel obstruction. The mechanisms of microvascular injury to the bowel in the setting of radiation have not been defined. We hypothesised that microvascular dysfunction with impaired vasodilation to acetylcholine (Ach) would be a n acquired pathophysiological abnormality in radiation and “web" formation. Met hods: A 40 year old patient treated with radiation, two years previously, for an anal squamous cell cancer presented with recurrent small bowel obstruction. “W ebs" in the distal ileum were detected using wireless capsule endoscopy, after s mall bowel barium radiographs failed to demonstrate a lesion. Following resectio n, freshly isolated 50-150 μmdiameter arterioles from the “web" and adjacent normal calibre bowel were analysed with histology and microvessel physiological studies. Results: After constriction (30-50%) with endothelin, dilation to gra ded doses of Ach (10-9-10-4 M) was observed in vessels dissected from the str icture and the adjacent normal calibre area. Ach dilation was reduced in vessels from “web" (mean diameter 7 (2)%; n = 3, p < 0.01) compared with the adjacent unaffected bowel (mean diameter 85 (5)%). Dihydroethidine and dichlorofluoresc ein diacetate intravital staining demonstrated increased reactive oxygen species production in microvessels from “web" compared with adjacent normal calibre bo wel. Histology from the structured bowel demonstrated narrowing of the arterial lumen due to intimal and muscularis propria fibrosis, with endothelial preservat ion. Conclusions: External radiation is associated with acquired microvascular e ndothelial dysfunction and “web" formation in the small bowel.
文摘Objective. To review our preliminary experience and evaluate our early results of a combined intraoperative iliac angioplasty and stenting with infrainguinal revascularization in multilevel atherosclerotic occlusive disease. Methods. From July 1999 to April 2000, intraoperative iliac angioplasty and stenting combined with simultaneous femoro- popliteal bypass were performed on 12 lower extremities of 10 patients suffering from multilevel atherosclerotic occlusive disease. There were 8 men and 2 women, average 72 years. The indications for procedures included disabling claudication in 3 and rest pain in 7 patients. Results. Eleven iliac angioplasty and stent procedures combined with simultaneous 9 femoro- popliteal bypass and 3 femoro- femoral- popliteal bypass were performed in 12 limbs of 10 patients. Angioplasty and stent placement was technically successful in all patients. One contralateral femoral- popliteal bypass was failure after femorofemoral- popliteal bypass. There were no additional instances of procedural or postoperative morbidity or mortali- ty. Mean follow- up was 5 months (range 1～ 10 months). During the follow- up period, one femoro- infrapopliteal graft became occluded after 7 months and above- knee amputation was required. The cumulative primary patency rate of stented iliac arteries, femoro- femoral bypass grafts and femoro- popliteal bypass grafts were 100％ (11/11), 100％ (3/3) and 90.9％ (10/11) in the follow- up period, respectively. The amputation rate was 8.3％ (1/12). Conclusions. Intraoperative iliac artery PTA and stent placement can be safely and effectively performed simultaneously with infrainguinal revascularization for multilevel atherosclerotic occlusive disease by skilled vascular surgeon, using a portable C arm fluoroscopy in the operating room. Furthermore, iliac artery PTA and stenting was valuable adjunct to distal bypass either to improve inflow and outflow, or to reduce the extent of traditional surgical intervention, and also, any angioplasty and stenting- related complications can be immediately corrected as well.
