External carotid endarterectomy: indications, operative technique, and results.

In the presence of chronic internal carotid artery occlusion, the external carotid artery becomes an important source of collateral circulation to the ipsilateral cerebral hemisphere and eye. It not only supplies blood via periorbital collaterals with retrograde flow in the ophthalmic artery, but also may allow emboli to reach the retina or brain. The cul-de-sac or "stump" created by internal carotid artery occlusion may frequently be the source of emboli causing amaurosis fugax or hemispheric transient ischemic episodes. Seven such patients presenting with amaurosis fugax and/or hemispheric transient ischemic episodes were found at operation to have atherosclerotic ulceration or platelet fibrin debris at the carotid bifurcation and the internal carotid artery cul-de-sac. These patients were treated by external carotid endarterectomy with excision and closure of the occluded internal carotid artery cul-de-sac to remove a potential source of stasis and platelet fibrin deposition. A preoperative angiogram and intraoperation photograph demonstrating the typical pathologic findings are presented. The surgical technique emphasizing excision and closure of the internal carotid cul-de-sac is illustrated. Six of the seven patients have remained asymptomatic with a 2- to 28-month follow-up. The importance of considering microembolism as a cause of symptoms in some patients without external carotid artery stenosis is stressed.

Tibial and peroneal artery anastomosis.

A technique of distal tibial and peroneal artery bypass vein grafting is presented. The principles are those of limited arterial dissection and minimal handling of the involved artery. A technique of suture placement that is applicable for all end-to-side anastomoses is described.

Inferior mesenteric artery aneurysm: case report and discussion.

Although visceral artery aneurysms are uncommon, an isolated inferior mesenteric artery aneurysm is reported. A 55-year-old man underwent aortofemoral reconstruction with resection of the aneurysm and replantation of the artery into the Dacron graft. This unusual entity is discussed.

Successful management of popliteal arterial disruption in Ehlers-Danlos syndrome.

A review of the literature on Ehlers-Danlos syndrome with particular attention to vascular complications enabled us to outline an orderly diagnostic and therapeutic plan which has allowed salvage of an individual with a popliteal false aneurysm. In patients with Ehlers-Danlos syndrome and brachial, superficial femoral, or popliteal arterial disruption, the use of proximal tourniquet control to allow ligation of the disrupted artery under a no-flow, no-pressure situation is recommended. The ligations should be carried out with a large ligature or possibly with large hemoclips and/or reinforced with multiple fine atraumatic vascular sutures distally. These patients may be treated successfully for flexion contractures because of the laxness of their tissues.

Aortocaval fistula associated with aneurysm of the abdominal aorta: current management using autotransfusion techniques.

Two patients with aortocaval fistula associated with abdominal aortic aneurysm were managed successfully using a patient care plan which includes proper monitoring of the hemodynamic state, careful dissection of the aneurysm, and return of blood loss by autotransfusion while the patient is fully anticoagulated with heparin. This unusual and serious problem in vascular surgery can be managed in an orderly and controlled fashion using these techniques.

Gastrointestinal bleeding and mycotic superior mesenteric aneurysm.

This is a case report of management of a delayed mycotic superior mesenteric artery aneurysm occurring in a patient 2 years after aortic valve replacement for endocarditis. A chronic ulcer history, anticoagulation therapy, episodic gastrointestinal bleeding associated with negative gastrointestinal series, and gastritis seen at endoscopy delayed the ultimate diagnosis. An episode of massive hemorrhage precipitated angiography with subsequent surgical confirmation of the diagnosis. Management included debridement and extirpation of the major part of the aneurysm, Doppler assessment of the inadequacy of collateral mesenteric arterial blood flow, and restoration of flow with a bypassing saphenous vein graft segment. Although this technique of reconstruction has been suggested, we can find no other report of such a similar case among the few reported surgical successes with superior mesenteric artery mycotic aneurysm.

Determination of intestinal viability by Doppler ultrasound.

The Doppler ultrasonic flowmeter was used to determine intestinal serosal and mesenteric blood flows in 130 patients who underwent abdominal aortic vascular procedures and in 14 patients who underwent general surgical procedures. Temporary occlusion of the inferior mesenteric artery (IMA) during aortic surgery resulted in the absence or marked diminution of collateral blood flow over the left side of the colon in eight patients. One patient had the flow in the IMA preserved by proper placement of an end-to-side aortofemoral Dacron prosthesis, whereas the other seven patients underwent replantation of the IMA into the Dacron prosthesis. All patients did well postoperatively. In the 14 general surgical patients, intestinal viability and collateral mesenteric blood flows were determined, which demonstrated that the presence of audible arterial blood flow correlated with ultimate bowel viability. We recommend the use of the Doppler ultrasonic flowmeter in abdominal aortic revascularization procedures to determine the need for IMA reconstruction as well as in general surgical procedures where the surgeon desires a more objective assessment of intestinal viability.

Sequential femoro-popliteal-tibial bypass grafting: operative technique and results.

Sequential femoro-popliteal-tibial saphenous vein grafts were constructed in 25 patients for limb salvage. Angiographically, these patients had an isolated popliteal artery segment and at least one distal tibial or peroneal artery patent. In each case, two distal anastomoses were made: one side-to-side to the isolated popliteal segment and the other end-to-side to a tibial or peroneal artery. Twenty-three of 25 grafts were successful; there was an immediate increase in ankle/brachial pressure index and limb salvage. Patency rates calculated by life table analysis were 90.2% at six months, 83.8% at one year, and a stable interval patency thereafter. For comparison, 65 standard femoro-tibial or peroneal vein grafts performed during the same time interval by the same surgeons were analyzed. Each graft had one distal anastomosis to a tibial or peroneal artery. Graft patency was 75% at six months, 72.6% at one year, 54.5% at two years, and 49.7% at three years. The superior patency rate of the sequential grafts was statistically significant (p less than .03). We conclude that the sequential vein graft technique may result in more complete extremity revascularization and increased graft flow, thereby improving patency rates. In selected patients with an isolated popliteal segment and a patent distal tibial or peroneal artery, the sequential graft technique should be considered.

Intraoperative high-frequency epicardial echocardiography in coronary revascularization: locating deeply embedded coronary arteries.

During coronary revascularization, the precise location of major coronary arteries may be obscured by overlying fat, myocardial bridging, or epicardial scarring. High-frequency epicardial echocardiography can be used intraoperatively to quickly image and locate such arteries and eliminate the need for time-consuming epicardial exploration or potentially deleterious retrograde probing of distal coronary artery branches. This technique can be applied using commercially available equipment and the aid of a skilled technician.

Anastomotic false aneurysms: a comparison of braided Dacron and polypropylene sutures.

False aneurysms continue to be a problem in vascular surgery and recently polypropylene suture has been incriminated as a major cause. In the last five years, 950 aortofemoral-popliteal reconstructive procedures were performed at our institution. Of these cases, there were 23 patients with anastomotic false aneurysms. We have reviewed this experience with special focus on suture material. In the 23 cases reviewed, there were a total of 29 false aneurysms. The average time interval from operation to clinical presentation of the false aneurysm was five years. Eighty per cent of the aneurysms were at the femoral site. The anastomoses were all end-to-side, and in 93 per cent the graft material was Dacron. The suture material that was used was divided equally between dacron and polypropylene. Aneurysms were blamed on broken suture in only one instance (silk). In 24 aneurysms where the graft had pulled away from the artery, the suture (10 polypropylene, nine Dacron, and two unknown) was noted to be intact. The suture line was not mentioned in one polypropylene and three Dacron related aneurysms. Retrospective review of these 29 false aneurysms leads us to the conclusion that there is no difference between polypropylene and braided Dacron as a factor in the formation of anastomotic false aneurysms in the period studied.

Aortofemoral bypass grafting: Microvel.

One hundred seventy-five patients underwent elective aortofemoral bypass during the years from 1976 to 1979. One hundred eighteen of these patients received a knitted double velour prosthesis (Microvel) and the remainder received standard knitted Dacron. All patients had been followed for a minimum of 12 months. Early graft thrombosis occurred in three limbs, and these were restored by reoperation for 100 per cent patency at discharge from the hospital. The operative mortality was three patients (1.7%). Complications included myocardial infarction (three/one death), renal failure (one/one death), respiratory failure (one/one death), cerebrovascular accident (four), and superficial wound infection (five). Late complications were infrequent, but included seven graft limb occlusions in six patients (3.4%), and one graft infection, one ureteral obstruction, and one false aneurysm. Among the 256 symptomatic extremities, claudication was completely relieved in 199 (78%) and substantially improved in an additional 48 (18.5%). Hemodynamic assessment with arm/ankle or arm/high thigh indices improved in parallel with symptomatic relief. Thus, only nine (3.5%) symptomatic extremities failed to improve with the proximal reconstruction, requiring distal reconstruction or amputation. The authors remain advocates of aortofemoral grafting with end-to-end proximal anastomosis and hooding of the distal anastomosis over the profunda origin for most aortoiliac occlusive diseases. Our recent experience with double velour graft and this technique have been very satisfactory.

Results of ophthalmosonometry and supraorbital photoplethysmography in evaluating carotid arterial stenoses.

A total of 263 patients underwent either periorbital ophthalmosonometry (Doppler ultrasound) or a combination of ophthalmosonometry and supraorbital photoplethysmography (SOPPG) to determine the presence or absence of a hemodynamically significant lesion (occlusion or greater than 50% reduction in lumen diameter). There were 522 vessels studied with Doppler ultrasound and 272 vessels with a combination of the two modalities. The tests were correlated with carotid arteriography to determine their accuracy. Overall accuracy of the Doppler ultrasound examination was 95%. A normal Doppler ultrasound examination was obtained in 367 vessels and arteriography confirmed the absence of a hemodynamically significant lesion in 93%. Of 155 vessels with an abnormal Doppler examination, 149 (96%) were proven on arteriography to have hemodynamically significant lesions. The Doppler ultrasound examination had a high incidence of false-negative examinations (26%) in those vessels that were between 50% and 99% stenotic, however. The SOPPG alone had a high incidence of false-positive examinations (19%); however, in 155 vessels with a normal SOPPG, 98% were proved to have no hemodynamically significant lesion. The combination of Doppler ultrasound and SOPPG was highly accurate in identifying patients with hemodynamically significant lesions. Of 97 vessels with such lesions, 96 (99%) had either an abnormal Doppler ultrasound examination or an abnormal SOPPG. In 240 vessels with concordant results of the Doppler ultrasound and SOPPG, the presence or absence of a hemodynamically significant lesion was accurately predicted in 235 (98%).

Relative importance of hypertension after coronary occlusion in chronic hypertensive dogs with LVH.

We have shown that there was a 50% increase in infarct size and a threefold increase in the incidence of sudden death following coronary occlusion in dogs with hypertension and left ventricular hypertrophy (LVH). To further investigate this problem, we separated the effects of hypertension from those of LVH by decreasing arterial pressure either by renal anastomosis or intravenous administration of nitroprusside in dogs with chronic renal hypertension and LVH. In 123 conscious dogs, the circumflex coronary artery was acutely occluded. Hemodynamics were monitored, myocardial perfusion was measured with labeled microspheres, the risk area was defined by postmortem angiography, and infarct size was determined pathologically 48 h after occlusion. The incidence of sudden death following acute coronary occlusion decreased dramatically in dogs with LVH if the arterial pressure was decreased with either nitroprusside or renal anastomosis. In addition, if arterial pressure was decreased with nitroprusside or renal anastomosis, infarct size in dogs with LVH was not augmented. In conclusion, normotension induced by renal anastomosis or nitroprusside returned infarct size and the incidence of sudden death in dogs with chronic hypertension and LVH toward control values. Thus it is likely that hypertension, as opposed to LVH, is the critical factor responsible for the increase in infarct size and the high incidence of sudden death observed in dogs with hypertension and LVH following sudden coronary occlusion.

Delineation of the extent of coronary atherosclerosis by high-frequency epicardial echocardiography.

Postmortem studies suggest that coronary angiography does not always accurately delineate the extent of coronary-artery disease. We examined this problem in living human hearts by performing high-frequency epicardial echocardiography at the time of cardiac surgery. The ratio of the diameter of the lumen of the coronary artery to the thickness of its wall was used to quantify the severity of coronary lesions. In 11 patients with no angiographic evidence of coronary disease anywhere in the coronary tree, the mean (+/- SEM) ratio was 5.9 +/- 0.3. In 21 patients with angiographic disease at the site evaluated by echocardiography, the mean ratio was lower (2.3 +/- 0.2, P less than 0.05), reflecting encroachment into the arterial lumen by atherosclerotic plaque. In 15 patients with arterial segments that were angiographically normal but with arterial stenoses elsewhere in the coronary tree, the mean ratio was 4.1 +/- 0.3, with marked overlap with the values in the patients who had angiographic disease at the site of the echocardiographic evaluation. These results demonstrate, in living human hearts, that diffuse coronary atherosclerosis is often present when coronary angiography reveals only discrete stenoses. This finding suggests that coronary angiography may underestimate the severity and extent of coronary disease.

The role of intraoperative high-frequency epicardial echocardiography during coronary artery revascularization.

The intraoperative evaluation of the technical adequacy of coronary artery bypass graft anastomoses has been limited by a lack of suitable tools. To evaluate the role of intraoperative high-frequency epicardial echocardiography we examined 82 coronary artery bypass graft anastomoses in 29 patients shortly before or just after weaning from cardiopulmonary bypass. Minor defects that did not compromise the lumen of the anastomoses were seen in two patients. One major technical error, a near total occlusion of an internal mammary-to-coronary artery anastomosis, was not apparent on external inspection, but was clearly identified with high-frequency epicardial echocardiography. This was revised immediately. Thus, high-frequency epicardial echocardiography permits the intraoperative evaluation of coronary artery bypass graft anastomoses so that technical errors can be quickly identified and corrected.

Intraoperative evaluation of coronary artery bypass graft anastomoses with high-frequency epicardial echocardiography: experimental validation and initial patient studies.

There is currently no accepted approach for intraoperative evaluation of the technical adequacy of coronary artery bypass graft anastomoses. High-frequency epicardial echocardiography performed intraoperatively could assess coronary artery bypass graft anastomoses by providing on-line short-axis (cross-sectional) and longitudinal two-dimensional images of the vessels. To validate measurements of anastomoses with high-frequency epicardial echocardiography, luminal diameter determined by high-frequency epicardial echocardiography was compared with that determined histologically after perfusion fixation in 12 dogs studied after coronary artery bypass grafting. Technical errors were deliberately created in some grafts. The results of these animal validation studies showed that maximum luminal diameter of the anastomosis by high-frequency epicardial echocardiography correlated well with histologic measurements (r = .92; high-frequency epicardial echocardiography = 0.8 histology + 0.3). All deliberately created technical errors were detected by an independent observer using high-frequency epicardial echocardiography. After completion of the animal studies, we demonstrated the clinical applicability of this approach in 12 patients. Fifteen coronary artery bypass graft anastomoses were examined intraoperatively with high-frequency epicardial echocardiography. The measured maximum luminal diameter of the anastomosis was greater than the maximum luminal diameter of the native artery, as expected, in all end-to-side anastomoses. However, the maximum luminal diameter of the side-to-side anastomoses was equal to or slightly less than that of the native artery. In this initial patient group, minor technical errors were noted in two of 15 graft anastomoses. In conclusion, high-frequency epicardial echocardiography can accurately measure coronary arterial bypass graft anastomoses and has potential for intraoperative detection of technical errors and inadequacies.