Pavel V. Petrik

Laparoscopic aortofemoral bypass. Initial experience in an animal model.

ObjectiveThe study objective was to evaluate the feasibility of laparoscopic aortofemoral bypass in a porcine model. Summary Background DataLaparoscopic techniques have been applied to numerous general and thoracic surgical procedures. Their application to vascular surgery has been virtually nonexistent. Open surgery for aortoiliac occlusive disease is accompanied by significant morbidity rates, and minimally invasive procedures have the disadvantage of reduced patency rates. Laparoscopic aortofemoral replacement has the theoretical advantage of long-term patency with reduced postoperative complications. MethodsBetween January and September 1993, laparoscopic surgery was performed on 16 pigs: 6 underwent transperitoneal laparoscopic aortic dissection and vessel control alone; 7 underwent complete transperitoneal laparoscopic aortofemoral bypass; and 3 underwent a retroperitoneal approach. The aortic anastomosis was performed using a combination of sutures and titanium clips in an end-to-side fashion in five pigs, and a custom-made nonsutured graft was secured with use of an end-to-end method in five pigs. Femoral anastomoses were performed with the standard open technique. ResultsTechnical success was achieved in all 10 animals and with no major complications. Mean blood loss was 20 ml (range, 5–50 ml), and mean operative time was 2.45 hours (range, 2–4 hrs). On aortic-clamp release, 2 of the end-to-side anastomoses required additional sutures to stop bleeding between oversized staples, and 2 of the end-to-end anastomoses required additional ties to reinforce loose ties. All 10 grafts and anastomoses were patent and free of leaks after completion of the procedure. ConclusionsLaparoscopic aortofemoral bypass is technically feasible in a porcine model. Further experimental work with new instrumentation and technical refinement will make laparoscopic surgery feasible for the treatment of vascular disease in humans.

Cigarette Smoking Accelerates Carotid Artery Intimal Hyperplasia in a Dose-Dependent Manner

BACKGROUND AND PURPOSE Intimal hyperplasia is the single most important cause of early restenosis after carotid endarterectomy. Cigarette smoking is an independent risk factor associated with peripheral vascular disease and cerebrovascular accidents. We undertook a dose-response experiment to determine the effect of cigarette smoke on development of intimal hyperplasia in a rat carotid artery intimal injury model. METHODS Seventy-two rats were divided into six equal groups and underwent standardized balloon injury to the carotid artery. Each group received 0 (controls), 1, 2, 3, 6, or 8 cigarettes per day for 4 weeks. Resultant intimal hyperplasia was expressed as a percentage of original lumen replaced by intimal hyperplasia. RESULTS Percent intimal hyperplasia development (+/- SD) was as follows: controls (0 cigarettes per day), 17.7 +/- 13.2; 1 cigarette per day, 22.8 +/- 15.0; 2 cigarettes per day, 20.0 +/- 14.7; 3 cigarettes per day, 19.2 +/- 12.1; 6 cigarettes per day, 43.5 +/- 15.5; and 8 cigarettes per day, 36.7 +/- 9.8. Six and 8 cigarettes per day significantly increased the development of intimal hyperplasia after intimal injury (P < .01). CONCLUSIONS High-dose cigarette smoke accelerates development of intimal hyperplasia and may pose a significant risk factor in developing carotid restenosis.

Cigarette smoking increases the development of intimal hyperplasia after vascular injury

PURPOSE Our purpose was to determine whether exposure to cigarette smoke increases the development of intimal hyperplasia (IH) after vascular injury. METHODS Sixteen adult male Sprague-Dawley rats underwent standardized balloon catheter injury of the left common carotid artery. For 4 weeks before and 4 weeks after injury, animals in the experimental group (n=8) were exposed to cigarette smoke with an automated vacuum pump device. Animals in the control group (n=8) were restrained in the smoking device for an identical amount of time and underwent arterial injury at 4 vivo, prepared as histologic cross sections, and stained for elastin. IH was measured by planimetry and is reported both as the absolute area of IH and as the ratio (IH/IEL) of the absolute area of IH to the normalized area enclosed by the internal elastic lamina (expressed as a percent). RESULTS The absolute area of IH was 2.09 +/- 0.34 for the experimental group compared with 0.94 +/- 0.25 for the control group; mean IH/IEL was 43% +/- 7.1% for the experimental group versus 17.7% +/- 4.7% for the control group (p < 0.05, two tailed unpaired t test. CONCLUSIONS Inhalation of cigarette smoke increases the development of intimal hyperplasia in a rat model of a balloon catheter arterial injury.

Computerized angiographic analysis of the outcome of peripheral thrombolysis

BACKGROUND Catheter-directed peripheral thrombolysis is used increasingly for the management of acute limb ischemia. The comparison of different agents and techniques has proven difficult because of the variations in patient presentation, vessel involvement, and treatment methods. METHODS A computerized database in which angiographic information is stored on computerized arterial maps has been designed to record details of thrombolysis. RESULTS A total of 201 patients who presented with rest pain were recorded on the database, and their angiograms were analyzed. There were 123 native-vessel and 78 graft occlusions. Immediate success of lysis and 30-day outcome were not dependent on the site of the occlusion. If an underlying stenosis was revealed, limb salvage rates were significantly greater than when none was found (82% versus 58%, P < 0.01). The presence of at least 1 run-off vessel increased limb salvage rates by 30% (P < 0.001). If more than 5 arterial segments were occluded on the prelysis angiogram, limb salvage was worse than if there were fewer than 5 (57% versus 85%, P < 0.0001). For grafts, less than 5 segments of occlusion led to limb salvage rates of 90%, and more than 5 segments of occlusion led to rates of 72% (P = 0.07). CONCLUSIONS This simple and user-friendly system of computerized angiographic analysis will enable detailed examination of thrombolytic practice and assist in the prediction of success.

Aspirin increases tissue oedema after skeletal muscle ischaemia and reperfusion

PURPOSE Skeletal muscle ischaemia reperfusion syndrome affects patients following lower limb revascularisation. Aspirin has the potential to attenuate these effects. METHODS Using an established model of hind limb tourniquet ischaemia, the effects of oral and intravenous aspirin administration were observed after 6 h of ischaemia and 18 h reperfusion. Samples were obtained and analysed for muscle viability and oedema, and lung neutrophil infiltration. RESULTS Aspirin, when compared to placebo and controls, significantly increased muscle interstitial oedema when given orally and intravenously. It had no effect on tissue viability or lung neutrophil infiltration. CONCLUSION Aspirin increases tissue oedema after ischaemia and reperfusion but has no effect on tissue viability. Although its mechanism of action has not been clarified, aspirin may influence the no-reflow component of ischaemia-reperfusion syndrome.