Association of ultrasonic texture and echodensity features between sides in patients with bilateral carotid atherosclerosis.

OBJECTIVES: Our objective was to estimate the correlation of echodensity and textural features, using ultrasound and digital image analysis, between plaques in patients with bilateral carotid stenosis. DESIGN: Cross-sectional observational study. METHODS: Patients undergoing carotid endarterectomy were recruited from Vascular Surgery at the Royal Victoria and Jewish General hospitals in Montreal, Canada. Bilateral pre-operative carotid ultrasound and digital image analysis was performed to extract echodensity and textural features using a commercially available Plaque Texture Analysis software (LifeQMedical Ltd). Principal component analysis (PCA) was performed. Partial correlation coefficients for PCA and individual imaging variables between surgical and contralateral plaques were calculated with adjustment for age, sex, contralateral stenosis, and statin use. RESULTS: In the whole group (n = 104), the six identified PCA variables and 42/50 individual imaging variables were moderately correlated (r = .211-.641). Correlations between sides were increased in patients with ≥50% contralateral stenosis and symptomatic patients. CONCLUSION: Textural and echodensity features of carotid plaques were similar between two sides in patients with bilateral stenosis, supporting the notion that plaque instability is determined by systemic factors. Patients with unstable features of one plaque should perhaps be monitored more closely or treated more aggressively for their contralateral stenosis, particularly if this is hemodynamically significant.

Treatment of aortic arch aneurysms with a modular transfemoral multibranched stent graft: initial experience.

OBJECTIVES: To present initial experience with a new modular transfemoral multibranched stent graft for treating aortic arch aneurysms. METHODS: Six patients, considered high risk for open surgery, were treated with custom made branched stent grafts. All patients had a staged left carotid subclavian bypass before the endovascular procedure. Each branched graft had a 12 mm side branch for the innominate artery and an 8 mm side branch for the left common carotid artery. RESULTS: Four patients out of six had uneventful placement of the prostheses, with successful exclusion of their aneurysms. One patient developed a type I endoleak that was managed successfully with coiling and gluing of the aneurysm sac. In one patient, cannulation of the innominate branch was unsuccessful and an extra-anatomic bypass was necessary to perfuse the right carotid and vertebral arteries. This patient developed a stroke, while one more suffered a right cerebellar infarct. CONCLUSION: We have demonstrated the technical feasibility of a modular transfemoral branched stent graft for treatment of aortic arch aneurysms. The method is relatively safe based on initial experience. More cases and long-term follow up are necessary to evaluate the efficacy and safety of this new device.

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow.

HYPOTHESIS: Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow. DESIGN: Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period. SETTING: University teaching hospital. PATIENTS: Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs). INTERVENTIONS: All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10). MAIN OUTCOME MEASURES: Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival. RESULTS: All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04). CONCLUSION: Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.

Early vascular complications after endovascular repair of aortoiliac aneurysms.

The purpose of this study was to estimate the frequency of and review the treatment options for intraoperative endograft access-related vascular complications and early postoperative vascular complications of endovascular repair for aortoiliac aneuryms (EVAR). Between February 1998 and April 2000, 53 patients (46 males, 7 females) with aneurysms of the abdominal aorta (AAA) and iliac arteries were treated with endovascular grafts (48 AAA, and 5 iliac aneurysms). All procedures were performed using open exposure of the femoral arteries. One patient with an AAA was converted to open repair (primary technical success, 98.1%). We recorded the need for adjunctive vascular procedures or intervention to the access arteries (iliofemoral) or the endograft because of thrombosis or distal embolization. Events were classified as either intraoperative, early postoperative (< 30 postoperative days), or late postoperative. Their etiology and treatment were recorded. The results were compared to those from other series reported in the literature and to published registry data. From our results we concluded that the need for adjunctive vascular procedures to the iliofemoral arteries at the time of EVAR is significant. These procedures are necessary to either repair damage to the access arteries from the delivery system or provide a conduit for graft delivery in cases where the access arteries are inadequate. Early postoperative vascular complications are due to technical factors resulting in residual graft limb stenoses. Both intraoperative and early postoperative vascular complications after EVAR are more common in female patients. These complications can be effectively treated with a variety of open surgical and transfemoral endovascular techniques.

The predictive value of intraoperative duplex for early vein graft patency in lower extremity revascularization.

This study was undertaken to evaluate the ability of intraoperative duplex scanning during infrainguinal vein bypass to identify technical abnormalities and to determine the relation between intraoperative scan result and early primary graft patency. We retrospectively reviewed of 78 consecutive intraoperative duplex scans for infrainguinal vein bypass that were performed between October 1993 and October 1996 during the course of infrainguinal vein bypass. Duplex scans were classified as normal or abnormal based on B-mode image and/or Doppler velocity spectra. Grafts were grouped according to duplex findings and intraoperative action: group I, normal intraoperative scan; group II, abnormal intraoperative scan, revised; group III, abnormal intraoperative scan, not revised. The relationship of intraoperative duplex scan findings to intraoperative graft revision to 1-month and 6-month primary graft patency by life table was analyzed. The analysis demonstrates that the results of intraoperative duplex scans can be used to identify grafts at low risk for early postoperative graft failure (groups I and II), and those at high risk for early postoperative graft failure (group III).

Videoendoscopic thoracic aorta-to-femoral artery bypass. A feasibility study in a canine model.

PURPOSE: This study was undertaken to determine whether videoendoscopic thoracic aorta-to-femoral artery bypass is a technically feasible operation. METHODS: An acute canine study involving five mongrel dogs was carried out. After the dogs had been given a general anesthetic, the femoral arteries were exposed in the traditional fashion. On the left side, a retroperitoneal, retrorenal tunnel was extended from the common femoral artery to the diaphragm. Under videoendoscopic control, the tunnel was opened through the posterior thoracic attachments of the diaphragm into the thoracic cavity. A Dacron graft was tunneled from the thoracic cavity on the left to the left groin. The thoracic aorta was controlled with a side-biting clamp, and an endoscopically performed end graft-to-side thoracic aortic anastomosis was created. After completion of the thoracic anastomosis, the left femoral anastomosis was created in a traditional manner. A left-to-right femoral bypass completed the lower extremity vascular procedure. An open thoracotomy was avoided. RESULTS: Videoendoscopic thoracic aorta-to-femoral artery bypass was successfully performed in all five animals. All components of the thoracic procedure, including exposure, dissection, vessel control, cross-clamping, and anastomosis, were performed through the thoracic ports with conventional laparoscopic instruments. Blood loss was minimal. All animals survived the procedure before being killed. CONCLUSION: Videoendoscopic thoracic aorta-to-femoral artery bypass is a technically feasible operation in a canine model. Advantages of this unique approach over the experimental laparoscopic and the traditional transperitoneal open aortofemoral bypass include ease of aortic exposure, ability to control a segment of disease-free aorta, and anastomosis in a disease-free segment of aorta. Potential advantages include decreased perioperative morbidity rates with the videoendoscopic approach. Before there is clinical consideration of this surgical approach, long-term experiments are required to demonstrate the safety of the procedure.

Anthelmintic effects of cyclosporin A on protoscoleces and secondary hydatid cysts of Echinococcus granulosus in the mouse.

Cyclosporin A (CsA), employed primarily as an immunosuppressant during the management of organ and graft transplants, exhibits anthelmintic properties. However, its efficacy against tapeworm infections in laboratory models is variable. A preliminary investigation has been undertaken to assess the action of CsA on the establishment and growth of protoscoleces and secondary hydatid cysts of ovine Echinococcus granulosus in mice. Administration of CsA in five consecutive daily doses, beginning 2 days prior to infection, resulted in significant reduction in cyst establishment (measured in terms of cyst masses, cyst numbers and cyst wet weights), when mice were autopsied 20 weeks post-infection. None of these parameters were significantly reduced when the drug was administered 18 weeks post-infection, although wet weight decreased by 42%. Ultrastructural examination of the germinal membrane and laminated layer of late-treated E. granulosus revealed abnormalities in all cysts studied whereas control and early-treated hydatids were normal. A case is made for the consideration of a clinical use for CsA for post-operative control of secondary hydatidosis and its efficacy against hydatid cysts is discussed.