Viktor Reichert

Balloon Occlusion of the Celiac Artery: A Test for Evaluation of Collateral Circulation Prior Endovascular Coverage

INTRODUCTION Visceral ischemia is a possible complication after endovascular coverage of the celiac artery (CA). A selective mesenteric angiography during simultaneous balloon occlusion of the CA imitates endovascular coverage and might therefore be suited for evaluation of collateral circulation. We report the feasibility of a balloon occlusion test (BOT) of the CA for this purpose. REPORT We performed a BOT in 5 patients selected for endovascular surgery with intended coverage of the CA. The BOT could demonstrate sufficient collateral circulation in all cases, which was not evident without occlusion of the CA. The most important collateral vessels were the pancreaticoduodenal arcades and the dorsal pancreatic artery. All patients tolerated the BOT well without abdominal symptoms or pathological laboratory findings. DISCUSSION Our report suggests that a BOT of the CA is a feasible and safe procedure. It can demonstrate collateral pathways before definite coverage is performed. This test might be useful for selection of patients prior intended coverage of the CA.

Implementation of an artificial neuronal network to predict shunt necessity in carotid surgery.

In carotid surgery, it could be useful to know which patient will tolerate carotid cross-clamping in order to minimize the risks of perioperative strokes. In this clinical study, an artificial neuronal network (ANN) was applied and compared with conventional statistical methods to assess the value of various parameters to predict shunt necessity. Eight hundred and fifty patients undergoing carotid endarterectomy for a high-grade internal carotid artery stenosis under local anesthesia were analyzed regarding shunt necessity using a standard feed-forward, backpropagation ANN (NeuroSolutions); NeuroDimensions, Gainesville, FL) with three layers (one input layer, one hidden layer, one output layer). Among the input neurons, preoperative clinical (n = 9) and intraoperative hemodynamic (n = 3) parameters were examined separately. The accuracy of prediction was compared to the results of a regression analysis using the same variables. In 173 patients (20%) a shunt was used because hemispheric deficits or unconsciousness occurred during cross-clamping. With the ANN, not needing a shunt was predicted by preoperative and intraoperative parameters with an accuracy of 96% and 91%, respectively, where the regression analysis showed an accuracy of 98% and 96%, respectively. Those patients who needed a shunt were identified by preoperative parameters in 9% and by intraoperative parameters in 56% when the ANN was used. Regression analysis predicted shunt use correctly in 10% using preoperative parameters and 41% using intraoperative parameters. Intraoperative hemodynamic parameters are more suitable than preoperative parameters to indicate shunt necessity where the application of an ANN provides slightly better results compared to regression analysis. However, the overall accuracy is too low to renounce perioperative neuromonitoring methods like local anesthesia.

A modified approach of proximalization of arterial inflow technique for hand ischemia in patients with matured basilic and cephalic veins.

OBJECTIVE Proximalization of arteriovenous inflow (PAI) is an established technique for treating patients with access-induced hand ischemia. However, a prosthetic graft, used as arterial inflow, could minimize the benefits of a purely native fistula. In this study, a new PAI technique is reported, which avoids the use of prosthetic grafts in patients with matured basilic and cephalic veins. PATIENTS AND METHODS Eight patients (seven men, one woman; mean age 62 (45-82) years old) with grade III/IV critical dialysis access-related ischemia (DARI) and with a pre-existing Gracz fistula underwent an operation using modified PAI. The basilic and cephalic veins were preoperatively matured. During the operation, the former arteriovenous anastomosis was closed and the basilic vein was used as arterial inflow. RESULTS All procedures were technically successful. All patients but one could be discharged with a warm, neurologically improved extremity with a significant reduction in pain. After a mean follow-up of 43.5 (0-52) months, there were no recurrent steal symptoms and all necrotic hand lesions healed. Two patients died during the follow-up, but with well-functioning fistulae. One fistula failed during follow-up and one further fistula was ligated because of chronic neurological damage, which was not improved after the PAI procedure. Four AVFs are still available for hemodialysis. CONCLUSIONS The modification of the PAI technique with a basilic vein as presented here showed similar results to the original PAI procedure. This new procedure does not require prosthetic grafts as in the original PAI technique or a central venous catheter and leads to the enlargement of the puncture site as a result of the superficialization of the basilic vein. Therefore, it is believed that this new technique could be a good option for those patients with matured cephalic and basilic veins who suffer from severe access-related ischemia.

Stent Grafts for Acute Traumatic Injury of the Thoracic Aorta: A Single-Centre Experience.

Objectives:The presented study reveals the single centre experiences with the minimally invasive endovascular repair for acute traumatic thoracic aortic lesions in the care of multitrauma patients.Methods:We reviewed ten patients with acute traumatic thoracic aortic lesions treated with a thoracic aortic stent graft between April 2001 and December 2006. The prospective collected data included age, sex, injury severity score, type of endovascular graft, endovascular operation time, length of stay, length of stay in the intensive care unit, and mortality. Followup data consisted of contrast-enhanced spiral computed tomography at regular intervals.Results:All patients (m:f 5:5; median age, 46 years; interquartile range [IQR], 29–68.5 years) suffered severe traumatic injury, the median Injury Severity Score was 39.5 (IQR 37.3–43). All endovascular procedures were technically successful, and the median operating time for the endovascular procedure was 90 min (IQR, 65–120 min). The overall hospital mortality was 20% (n = 2), and all deaths were unrelated to the aortic rupture or stent placement. No incidence of paraplegia was present. No intervention-related mortality occurred during a median follow-up of 14.7 months (IQR, 9.7–55.8 months).Conclusion:The endovascular approach to acute traumatic thoracic aortic lesions is feasible, safe, and effective in multitrauma patients. The low endovascular therapy-related morbidity and mortality in the postoperative period is encouraging. The results seem to be favorable to those published of open emergency repair.