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Biomedical subjects

W M Stone

Publications and source records attributed to W M Stone.

At least 19 recordsLinked to original sources

Superior mesenteric artery aneurysms: is presence an indication for intervention?

INTRODUCTION: Although rare, superior mesenteric artery (SMA) aneurysms have a definite rupture risk. Past reports have suggested that this risk is low, yet most investigators recommend repair in selected patients. We reviewed our experience with 21 patients to try to determine when intervention was indicated. METHODS: A retrospective review of the medical records of all patients with SMA aneurysms at our institutions from January 1980 through December 1998 was undertaken. Only patients with true aneurysms of the SMA were included. RESULTS: Twenty-one patients with true SMA aneurysms were identified and included 14 males (67%) and seven females (33%). This represents a 6.9% incidence rate of all visceral aneurysms seen at our institutions. Eight patients (38%) had rupture at presentation, including seven of the 14 males (50%). In contrast to previous reports, only one patient (4.7%) had an infectious etiology. Five patients were on beta-blocker therapy, but none were seen with rupture. However, eight of the remaining 16 patients (50%) without beta-blockade had rupture. Thirteen patients (62%) had calcified aneurysms, but all ruptures were seen in noncalcified aneurysms. Operative intervention occurred in 11 of the 21 patients (52%). All eight patients with rupture underwent operation, including six ligations and one successful embolization, and one patient died before completion of repair. The operative mortality rate was 37.5% for ruptured aneurysms. Elective repair included one prosthetic graft, one excision and patch angioplasty, and one embolization, with no mortality. Ten of the 21 patients (48%) with SMA aneurysms were observed, and all were alive and well at a mean of 67 months' follow-up (range, 2 to 148 months). CONCLUSION: SMA aneurysms are rare but appear to have a higher risk of rupture than previously reported. Male patients and patients with noncalcified aneurysms appear to have a greater risk of rupture. beta-Blockade may have some protective effect against aneurysm rupture. Intervention is reasonable in all patients at good operative risk with SMA aneurysms, considering the high rupture rate in our series.

Adrenergic beta-Antagonists↗

Management of true aneurysms distal to the axillary artery.

OBJECTIVE: To delineate management strategies and outcomes for true aneurysms involving arteries of the upper extremity distal to the axillary artery. The management of these rare lesions has not been well established in the literature. METHODS: Retrospective chart review was performed at tertiary referral centers. All patients who received the diagnosis of true upper extremity aneurysms distal to the axillary artery between 1975 and 1995 were included in the review. Nineteen patients were found; seven were excluded because no confirmatory diagnostic imaging study or operative exploration was performed. This represents the largest reported series of true upper extremity arterial aneurysms. RESULTS: Twelve patients (9 men or boys) had 12 confirmed true aneurysms of the brachial or more distal arteries. The average diameters were as follows: brachial artery 4.6 cm, radial artery 2.0 cm, ulnar artery 1.4 cm, and digital artery 0.8 cm. The mean age was 51 years (range, 10 to 86 years). The most common presentation was the presence of a mass. This occurred among eight patients (67%). Four patients (33%) reported pain or paresthesia. One patient (8%) had cold intolerance only. Three patients (25%) had thromboembolic complications. Complications did not consistently correlate with size or presence of intramural thrombus. Three aneurysms (25%) were initially managed nonoperatively and followed for a mean period of 71 months. One of these required operative repair after 5 months because of progressive pain. Ten patients (83%) were treated surgically as follows: five underwent ligation and excision only, and five underwent excision and revascularization. Morbidity was minimal, and there were no perioperative deaths. CONCLUSION: True arterial aneurysms of the upper extremity distal to the axillary artery are rare and most commonly caused by blunt trauma. Fifty-eight percent of these lesions present with symptoms or complications. Thirty-three percent of asymptomatic lesions later become symptomatic. These factors combined with the minimal morbidity associated with repair suggest that operative repair should be routinely performed for these aneurysms. Revascularization can be performed selectively.

Adolescent↗

Early extubation after abdominal aortic reconstruction.

OBJECTIVE: To assess the safety of early (<2 hrs) extubation after elective infrarenal aortic surgical procedures. DESIGN: A retrospective chart review of 192 consecutive elective infrarenal aortic surgical procedures from January 1990 to March 1994 at Mayo Clinic Scottsdale was undertaken. MEASUREMENTS AND MAIN RESULTS: Combined general and epidural anesthesia was used extensively (187 patients; 97.4%). Early extubation was accomplished in 166 (86.5%) patients. Time to extubation was dependent on clinical factors and not by protocol. All early extubations occurred in the operating room or recovery room with a median time from skin closure of 12 minutes. Ten patients were extubated from 2 to 12 hours after the procedure, 14 patients more than 12 hours after the procedure, and 2 patients were not extubated and subsequently expired. Of the 166 patients extubated within 2 hours, 8 (4.8%) required reintubation. Factors found univariantly to be significantly associated with failure of early extubation include obesity, abnormal chest x-ray postoperatively, prior myocardial infarction, and prior coronary revascularization (p < 0.05). CONCLUSION: Early extubation (<2 hrs) after elective infrarenal aortic procedures may be performed safely and should be undertaken unless clinical features suggest failure of extubation.

Aged↗

Reduplicative paramnesia: longitudinal neurobehavioral and neuroimaging analysis.

Reduplicative paramnesia (RP) is a delusion in which the patient perceives familiar places, objects, or events to have been duplicated. The current case describes the development of RP in an 81-year-old male following a large right frontal lobe infarction. As the patient had been hospitalized previously with hemorrhagic contusions, neurologic, neuropsychological, and neuroimaging data were obtained both prior to and following RP onset. Psychophysiologic data were obtained following the development of the delusion. Both premorbidly and at follow-up, neuropsychological functioning was characterized by significant impairments of learning and memory and frontal-executive functions. Language and visuospatial skills and motor speed were intact both before and after RP onset. The case is described within the context of preexisting theories of RP, and it is surmised that the delusion is secondary to temporal-limbic-frontal dysfunction giving rise to a distorted sense of familiarity and impaired ability to resolve the delusion via reasoning.

Accidental Falls↗

A critical analysis of adjuvant techniques used to assess bowel viability in acute mesenteric ischemia.

Delayed revascularization and inaccurate assessment of bowel viability in acute mesenteric ischemia can be catastrophic. We reviewed the outcome of three popular adjuvant techniques used to evaluate bowel viability in all 16 patients who had second-look abdominal explorations following revascularization for acute mesenteric ischemia from 1984 to 1989. Each adjuvant technique was reviewed separately and compared with the unequivocal end points of viable or nonviable bowel. The sensitivity (percentage of nonviable bowel correctly identified), specificity (percentage of viable bowel identified), predictive value (percentage of bowel identified as "nonviable" that proved to be so), and overall accuracy (percentage of correct evaluations) were determined for each method. The overall accuracy of clinical judgment, fluorescein fluorescence, and Doppler was 50 per cent, 56 per cent, and 0 per cent, respectively. Based on this critical review, we recommend routine second-look explorations in patients with acute mesenteric ischemia to reassess bowel that has been predicted to be viable or to resect bowel that has progressed to infarction.

Acute Disease↗

Intestinal ischemia complicating abdominal aortic surgery.

A 9-year experience with 2137 patients undergoing infrarenal abdominal aortic reconstruction was reviewed to determine both the incidence of intestinal ischemia and the clinical, anatomic, and technical factors associated with this complication of aortic surgery. A total of 24 (1.1%) patients had overt intestinal ischemia, documented by reoperation or endoscopic findings. Of these, colon ischemia occurred in 19 (0.9%) and small bowel ischemia developed in 5 (0.2%) patients. The incidence after elective operation for aneurysmal or occlusive disease did not differ, but patients with ruptured aneurysms and those undergoing reoperative procedures for total graft replacement were at higher risk. Preoperative angiography was most helpful in ascertaining risk. Ligation of a patent inferior mesenteric artery was the most common (74%) feature in patients with colon ischemia. With preexisting inferior mesenteric artery occlusion, impairment of collateral circulation was attributable to superior mesenteric artery disease, dissection or retractor injury, prior colon resection, or exclusion of hypogastric perfusion. Bloody diarrhea was the most frequent postoperative symptom and colonoscopy the most reliable means of diagnosis. One half of patients with colon ischemia required resection after late recognition of perforation. All cases of small bowel ischemia were related to superior mesenteric artery disease or injury or use of suprarenal clamping. The overall mortality rate was 25% but rose to 50% if bowel resection was required. Intestinal ischemia remains an infrequent but serious complication of aortic surgery. Despite a multifactorial cause, identification of patients at increased risk can lead to operative strategies to reduce its occurrence.

Aged↗

Aberrant right subclavian artery: varied presentations and management options.

Although an aberrant right subclavian artery arising from the proximal portion of the descending thoracic aorta is the most common aortic arch anomaly, few patients have clinical symptoms directly attributable to it. When symptoms do occur they are usually causally related to aneurysmal or occlusive sequelae of atherosclerotic disease of the anomalous vessel. More unusual manifestations peculiar to the anomalous artery include aneurysmal degeneration of the origin of the vessel from the aortic arch, with its inherent risk of rupture, or symptoms of compression of the trachea or more commonly the esophagus by the anomalous vessel as it traverses the superior mediastinum. In patients with symptoms a variety of operative approaches and management strategies have been used. Our recent experience with treatment of two patients with clinical symptoms caused by an aberrant right subclavian artery illustrate the varied surgical options and prompted a review of the surgical management of this unusual anomaly.

Adult↗

Chronic pancreatitis. Results of Whipple's resection and total pancreatectomy.

The aim of our study was to determine the success of radical pancreatic resection in relieving the pain of chronic pancreatitis. From 1974 to 1985, 30 consecutive patients underwent radical pancreatic resection for the treatment of debilitating pain (15 underwent Whipple's resection and 15 underwent total pancreatectomy). Patients were not randomized but were subjected to the procedure deemed indicated for their clinical presentation; thus, the two groups were not strictly comparable. There was no operative mortality; major morbidity occurred in three patients (20%) in each group (four patients experienced anastomotic bile leak and two experienced abdominal sepsis). Following Whipple's resection, mean follow-up was 6.2 years (range, 1.5 to 12.1 years). Complete pain relief occurred in eight patients (53%) and significant relief in an additional four (27%). Endocrine insufficiency developed in six patients and exocrine insufficiency in eight. Following total pancreatectomy, mean follow-up was 9.1 years (range, 2.1 to 13.1 years). Complete pain relief occurred in only four patients (27%) and significant relief in an additional six (40%). Significant pain persisted in about 33% of patients after total pancreatic resection. We concluded that radical pancreatic resection can be performed safely in patients with chronic pancreatitis but with gratifying results in only 67% to 80% of patients. Whipple's resection may be preferable for disease located primarily in the head of the gland.

Adult↗

Strongyloides ransomi: prenatal and transmammary infection of pigs of sequential litters from dams experimentally exposed as weanlings.

Prenatal infection of pigs with Strongyloides ransomi occurred in 12% of 104 pigs and in 14% of 21 litters farrowed by 13 sows experimentally exposed to infective larvae as weanlings. Transmammary passage was observed in 38 of 39 litters studied. Milk samples obtained from 14 sows showed that larvae were usually shed in the colostrum within 24 hours after farrowing; however, larvae were recovered from samples of milk of sows up to 20 days after parturition. Larvae were recovered from milk samples obtained after each parturition up to the fourth. Prenatal infection in pigs was not detected after the 1st litter.

Animals↗