Primary aortoduodenal fistula after radiotherapy.

Primary aortoduodenal fistula is an uncommon cause of massive upper gastrointestinal hemorrhage; it is most commonly caused by the erosion of an abdominal aortic aneurysm into the third portion of the duodenum. This report describes a 73-yr-old man who developed uncontrollable hematemesis due to a primary aortoduodenal fistula in the fourth portion of the duodenum approximately 20 yr after radiotherapy and para-aortic lymph node dissection for seminoma. Surgical and postmortem examination revealed encasement of a normal-size aorta by dense fibrous tissue, ischemic necrosis of the aortic wall, and distinct chronic radiation changes of the duodenum. We propose that radiation may have played a significant role in the pathogenesis of the aortoduodenal fistula in this case. A history of radiotherapy may be relevant in the etiology of massive gastrointestinal bleeding and should prompt rapid attempts at visualization of the distal duodenum if the source of bleeding is unclear.

The selection for shunting in patients with severe bilateral carotid lesions.

Patients with severe bilateral carotid lesions (stenosis and contralateral internal carotid occlusion) are at high risk of having a stroke, and carotid endarterectomy has been proposed as the best treatment. In spite of improvements in surgical technique, this operation is still associated with significant perioperative complications (5-13%) which are frequently (up to 40%) correlated with intolerance to internal carotid artery clamping. For this reason, intraoperative cerebral monitoring able to accurately detect ischaemia during surgery would be useful. Reviewing our experience from the last 7 years in 74 patients operated on for stenosis and contralateral occlusion of the internal carotid artery, we found a 1.3% neurological morbidity and 1.3% mortality rate. Presenting symptoms included focal transient ischaemia attacks (TIAs) in 57 patients, stroke in 16 patients and two patients were asymptomatic. Half of these patients (37) were operated on under general anaesthesia with electroencephalogram (EEG) monitoring, stump pressure measurement and selective shunting. In this group, two patients (5.4%) sustained a postoperative stroke, one of which was fatal. The remaining 37 patients were operated on under local-regional anaesthesia with selective shunting on the basis of neurological deficit onset or loss of consciousness during the test clamp. There were no postoperative neurological complications in this group but one patient died of acute myocardial infarction on the 6th postoperative day. This experience suggests that it is possible to perform carotid endarterectomy in patients with severe bilateral lesions with a postoperative complication rate similar to that in patients with less complicated obstructive lesions if accurate intraoperative cerebral monitoring is used.

Detection of aortic graft infection with leukocytes labeled with technetium 99m-hexametazime.

PURPOSE: To reduce the rates of morbidity and mortality in aortic graft infection, a new diagnostic approach is needed to help identify low-grade stages, specifically when there are minimal or no clinical signs of overt infection. The aim of this study was to evaluate the role of technetium 99m--hexametazime white blood cell scanning (99mTc scanning) in detecting aortic graft infection, particularly in the low-grade stages. METHODS AND RESULTS: Thirty-seven patients with suspected aortic graft infection were categorized into three groups according to their signs and symptoms on readmission. Ten patients (group A) had advanced graft infections that were correctly diagnosed by use of computed tomography (CT) scanning and 99mTc scanning and confirmed by intraoperative findings and culture results. Eighteen patients (group B) had nonspecific signs and symptoms of graft infection. Patients only underwent CT and 99mTc scanning for graft infection after standard clinical work-ups failed to reveal disease processes that accounted for the clinical symptoms. In this group of patients 99mTc scanning identified four cases of low-grade graft infection, which was confirmed by intraoperative findings and graft cultures. None of these four cases was confirmed by results of CT scanning. On an average 18-month follow-up in patients who did not undergo surgery graft infections developed. Nine patients (group C) had anastomotic aneurysms; CT scanning and 99mTc scanning correctly diagnosed five patients as being infected. The result of 99mTc scanning was false-positive in one patient. CONCLUSIONS: The diagnostic accuracy of 99mTc scanning in patients who did not have specific signs of graft infection (groups B and C) was 100% for sensitivity, 94.4% for specificity, 90% for the positive predictive value, and 100% for the negative predictive value. 99mTc scanning seems to be a useful diagnostic technique for detecting aortic graft infection, particularly in low-grade stages.

Preliminary results of a complete study protocol on synthetic vascular graft healing and its complications.

The microscopic and anatomic features and bacteriologic culture results of different portions of single, explanted dacron synthetic vascular grafts (SVG) were studied together with patient clinical data. With this complete study protocol a better understanding of the healing process and its associated pathology can be achieved. We studied three, amply distanced graft portions from each of five patients (15 total graft portions) undergoing revision for infectious and non-infectious reasons. We divided the SVG portions studied into a Group 1, with high degrees of graft healing and into a Group 2, with both infection-dependent, early healing complications and perigraft chronic inflammatory reaction-dependent, late healing complications. These late healing complications were found dependent upon a host vs graft reaction. This study confirmed in humans the important role of an internal and external fibrotic graft incorporation in the definitive healing of a SVG. A host vs graft reaction was suggested to be an alternative to the frequently cited low virulent infection pathogenesis of late SVG healing complications. A sure definition and treatment of late SVG healing complications will only be established by means of a complete study protocol performed on a large number of explanted SVGs.