Compartment syndrome after elective revascularization for chronic ischemia. A case report and review of the literature.

Compartment syndrome is a rare but serious complication of vascular reconstruction. It most commonly occurs following revascularization of an acutely ischemic extremity. This case of compartmental syndrome following bypass surgery for chronic arterial insufficiency is therefore exceedingly unusual. A review of the literature reveals only a few cases with similar presentation. The diagnosis can usually be made on the basis of clinical manifestations combined with compartmental pressure measurement. A timely, four-compartment fasciotomy can avert serious complications with minimal morbidity. Late recognition and treatment of this complication, as well as inadequate decompression, can lead to loss of limb.

Unilateral renal artery stenosis seen initially as severe and symptomatic hypokalemia. Pathophysiologic assessment and effects of surgical revascularization.

Hypokalemia is an uncommon presentation of renovascular hypertension. Although renal artery stenosis has been associated with hypokalemia secondary to hyperreninemic hyperaldosteronism, few reports have actually evaluated the pathophysiologic changes in such a patient with renovascular hypertension. We studied a patient before and after surgical revascularization who presented with severe hypertension and marked, symptomatic hypokalemia. Before surgery, the patient had excessive urinary potassium secretion, markedly increased secretion of renin after captopril stimulation, and mild secondary hyperaldosteronism. Postoperatively, the patient's blood pressure decreased moderately and the serum and urinary potassium values normalized. After revascularization, plasma renin activity both before and after captopril stimulation and serum aldosterone levels decreased markedly. These findings demonstrate that renovascular hypertension may rarely present with symptomatic hypokalemia secondary to excessive aldosterone secretion. Improvement in the renal ischemic state is accompanied by rapid correction of the metabolic disturbances associated with hyperreninemic hyperaldosteronism.

Survey of residents' attitudes toward reform of work hours.

Traditional work schedules of surgical residents have been cited as a factor that negatively influences residency education and the quality of patient care. As an adjunct to the formulation of recommendations for the development of the environment for general surgery training, the New England Association of Program Directors in Surgery set out to sample the attitudes of surgical residents in New England relative to their perceived need to reform work hours. Seventy-two percent of the residents thought there was a need for some level of resident work schedule change. The major variable that correlated with this opinion was the reported amount of sleep that a resident needed before returning to work after a 24-hour shift. The ultimate effect on education, patient care, and fiscal resources of these potentially sensitive changes remains to be determined.

Branched nonreversed saphenous vein graft for complex renal artery stenosis.

Use of recently developed instrumentation for venous valvotomy allows rapid construction of a branched, nonreversed saphenous vein graft. This technique was applied in a patient with renovascular hypertension and branch renal artery occlusive disease.

Release of chemotactic factors by veins during preparation for arterial bypass.

With the use of arterial bypass release neutrophil chemotactic factors, saphenous veins were removed from dogs by means of standard surgical technique and were distended to a pressure of 200 mm Hg for 15 minutes with cold (4 degrees C) plasmalyte solution. Veins cannulated in situ and flushed with cold (4 degrees C) plasmalyte solution served as negative controls. Experimental and control flush solutions were assayed for the presence of neutrophil chemotactic factors with the use of modified Boyden chambers. Chemotactic activity from the distended vein grafts was 2.2 to 7.2 times the control value. Biologic chemotactic activity was demonstrated as well. These results suggest a role for the vein graft itself in the recruitment of neutrophils to implanted veins by releasing chemoattractants.

Preliminary assessment of a scientific curriculum in a surgical residency program.

A structured, basic science curriculum was instituted for surgical residents of the University of Connecticut (Farmington) Integrated Residency Program during the 1990-1991 academic year in concordance with American Board of Surgery guidelines. The impact of the new program was measured by comparing performance on monthly basic science examinations, the in-training examination, and "mock" oral examinations for the 1990-1991 academic year with that of the preceding academic year. While monthly examination scores improved for the entire group of residents (67.7 vs 64.6), in-training and oral examination scores did not change significantly. Categorical residents generally demonstrated superior performance and greater improvement than did preliminary residents. Data analysis suggested that the new curriculum was an effective educational device and that university-designed monthly examinations were valid testing instruments, but there was an apparent incongruity between the goals of the curriculum and the American Board of Surgery In-Training Examination.

Internal carotid artery aneurysm: a vascular manifestation of type IV Ehlers-Danlos syndrome.

Aneurysms of the distal internal carotid artery (ICA) can be difficult to manage. When seen in a patient with Ehlers-Danlos Syndrome, type IV (EDS-Type IV), the complexity of the problem is greatly increased. Proximal ICA ligation in the presence of an intact circle of Willis and adequate collateral circulation is a reasonable and safe approach. We recommend the liberal use of duplex scanning and intravenous digital angiography in patients with EDS, and plan to use these techniques to follow the small, asymptomatic, right ICA aneurysm in our patient. If the aneurysm rapidly grows or becomes symptomatic, treatment may require proximal ligation with extracranial-intracranial bypass. Understanding of the basic defects associated with EDS-Type IV will make the management of patients with vascular complications more safe.

Outcome analysis of carotid endarterectomy in Connecticut: the impact of volume and specialty.

The purpose of this study was to define the relationship between the surgeon's operative experience and specialty and the postoperative morbidity and mortality of carotid endarterectomy. All patients undergoing carotid endarterectomy (code ICD-9CM 38.12) in Connecticut between October 1985 and September 1991 were retrospectively identified. A total of 3997 carotid endarterectomies were performed by 226 surgeons in four specialties: general, cardiac, vascular, and neurosurgery. Individual surgeon volume ranged from fewer than one per year to 27.5 per year (mean 2.9 carotid endarterectomies per year). Outcome was measured as a combined stroke and/or death percentage. The average combined stroke and/or death rate for the entire group was 4.9%. The combined stroke and/or death percentage was influenced significantly by the surgeon's annual volume. Surgeons who performed one or fewer carotid endarterectomies (43% of total surgeons) were 2.5 times more likely (p < 0.002) to have a poor postoperative outcome than those who performed 10 or more per year (9.3% of total surgeons). Overall there was a statistically significant correlation between a surgeon's annual volume and outcome, particularly for general surgeons.

Early carotid endarterectomy in patients with small, fixed neurologic deficits.

Patients who have sustained a large hemispheric stroke are not candidates for early carotid endarterectomy, but there is less agreement regarding the role of carotid endarterectomy in patients with small, fixed neurologic deficits. Accepted practice in many centers is to wait 4 to 6 weeks after the onset of the deficit before proceeding with carotid endarterectomy because of the fear that early revascularization will increase the size of the infarct. Earlier endarterectomy, however, in patients with significant residual ipsilateral carotid territory at risk may prevent repeated infarctions. For the past 5 years our approach to patients with a small stable stroke and significant stenosis (greater than 75%) has been prompt ipsilateral endarterectomy. Of the 337 carotid endarterectomies at our institution since 1979, a subset of 28 patients with hemodynamically significant carotid lesions presented with a small, fixed stroke. The period of time between the appearance of the stroke and carotid endarterectomy averaged 11 days, but 53% of patients were operated on within 7 days of the onset of symptoms. Selective shunting based on intraoperative EEG monitoring was utilized and 40% of the 28 patients required shunts. Operative mortality consisted of one death from a pulmonary embolus, and no patient sustained a new postoperative deficit. Long-term follow-up was available for 96% of patients over a mean of 2 years. During this time two new neurologic events occurred: one fatal stroke and one transient deficit. This experience indicates that patients with small, fixed neurologic deficits who continue to have carotid territory at risk may safely undergo carotid endarterectomy without waiting 4 to 6 weeks.

Functional analysis of cryopreserved veins. Preliminary report.

Functional comparisons of cryopreserved and fresh canine vein endothelium, smooth muscle, and connective tissue were performed. Morphometric analysis of saphenous vein endothelium revealed no significant loss of endothelial integrity as a result of cryopreservation. Endothelial cell culture revealed similar numbers of clonogenic intimal cells from cryopreserved and fresh saphenous, cephalic, and jugular veins. Smooth muscle function was assessed by measurement of the isometric force generated by vein rings in response to norepinephrine, serotonin, and potassium chloride. There was no significant difference in the dose responses of cryopreserved and fresh saphenous veins to the reagents tested. Similar results were obtained for the cephalic and jugular vein experiments with norepinephrine. The maximum tensions generated in response to norepinephrine were 52% of fresh control segments. Connective tissue function was assessed by quantitation of 3H-proline incorporation. The results indicate that cryopreserved veins retained approximately 43.5% of values of fresh vein collagen synthesis. Finally, eight cryopreserved cephalic vein autografts were placed as femoral artery grafts and were removed electively after 1 to 8 weeks. All grafts were patent. Both light and electron microscopy demonstrated that the cryopreserved veins remained intact in vivo and that arteriolization occurred as described for fresh autografts in the literature. In conclusion, cryopreserved veins retain much of their cellular and tissue functions on thawing. Transplantation of cryopreserved veins suggests that cryopreservation does not change the sequence of histologic events associated with the use of autologous fresh vein as an arterial substitute.

Coronary artery disease in patients requiring abdominal aortic aneurysm repair. Selective use of a combined operation.

The chief cause of operative mortality after abdominal aortic aneurysm (AAA) repair is myocardial infarction. For this reason, routine coronary angiography followed by prophylactic coronary artery bypass grafting (CABG) prior to AAA repair has been recommended by some surgeons. We report here the results of the selective use of a combined operation. Two hundred twenty-seven patients had elective or emergency repair of nonruptured AAA on our service from 1972 to 1983. Prior to surgery, all patients underwent careful clinical evaluation for the presence of coronary artery disease (CAD) and were classified into the following: group I (n = 121), no clinical evidence of CAD, 53%; group II (n = 96), clinical evidence of stable CAD, symptomatic or asymptomatic, 42%; group III (n = 10), unstable CAD, five per cent; Group IIIa (n = 4), asymptomatic AAA; and group IIIb (n = 6), symptomatic AAA. Seven patients ultimately assigned to group II underwent stress electrocardiogram (ECG) and eight group II patients had coronary angiography before surgery. All patients in groups I and II underwent elective or urgent repair of their AAA without CABG. Prior to surgery, these patients were managed with placement of a pulmonary artery catheter and incremental volume loading to construct a left ventricular performance curve as a guide to surgical fluid replacement. All were carefully monitored for at least 48 hours after surgery in an intensive care unit. Four patients (group IIIa) with unstable CAD and asymptomatic AAA underwent CABG followed by elective AAA repair within six months. Six patients (group IIIb) with unstable CAD and symptomatic AAA underwent combined open heart surgery (CABG and, in one patient, valve replacement) and AAA repair as a single operation. There was no operative mortality in group III patients. Thirty-day operative mortality for the entire group of 227 patients was 1.3% (three deaths), with only one death from a myocardial infarction (0.4%). While there is clearly a high incidence of CAD in patients with AAA, the present results indicate that these individuals can be managed with low risk by a selective approach based upon clinical assessment of their CAD. Our experience further demonstrates that patients with unstable CAD and symptomatic AAA may have both lesions safely repaired as a single operative procedure.