Detection of experimental arterial defects by portable and serial biplanar operative arteriography.

The accuracy of arteriography in detecting vascular defects similar to those encountered during vascular surgery was evaluated experimentally. Intimal flaps, thrombi, and strictures were created in dog aortas and studied under circumstances resembling operating room conditions by single-view portable and serial biplanar contrast arteriography. The specificity of both types of arteriography was comparable and high for detecting vascular defects. The sensitivity for diagnosing strictures was also comparable and high. However, both radiographic techniques were relatively insensitive in the detection of small intimal flaps and thrombi. In the detection of these two types of defects, serial biplanar arteriography was significantly more sensitive than portable arteriography. The degree of the superiority of serial bi-plane and the possible clinical insignificance of small defects indicates that portable arteriography in the operating room may still be an adequate methodology.

Ultrasonography of blood during stasis and coagulation.

A series of in vitro and animal experiments were performed to determine ultrasonic features of blood during stasis and coagulation. Liquid whole blood became echogenic within a few seconds to 3 minutes following the onset of stasis. This occurred in citrated human blood allowed to stand and in occluded segments of vena cava and aorta of dogs. Mechanical agitation of the blood in stasis caused a disappearance of echoes. This echogenicity occurred with gray-scale and real-time ultrasonography using 7.5-mHz transducers, but was not observed with 3.5-mHz transducer used in real-time scanning. Whole blood clot was echogenic both with 7.5- and 3.5-mHz scanning. Fibrin clot was sonolucent. Echogenicity with stasis did not occur with plasma, serum, or packed erythrocytes. The development of echogenicity required the presence of fibrinogen or its products plus erythrocytes. The echogenicity of blood during stasis detectable by high-frequency ultrasonography probably was related to physical layering of blood products. The disappearance of reflective echoes following agitation suggested that the layering could be readily disrupted.

Cardiovascular lymphoscintigraphy.

The technique of lymphoscintigraphy when applied to the heart and blood vessels correlates well with results of anatomic investigations of arterial and cardiac lymphatic vessels reported in the literature. Five dogs and eight rabbits underwent lymphoscintigraphy of the heart and aorta, as well as the iliac, femoral, and tibial arteries. After surgical exposure, approximately 500 microCi of 99mTc-labelled antimony sulfide was injected into the myocardium or the adventitial-medial plane of an artery. The colloid particle size of 4 to 12 m mu causes resorption and transport only via the lymphatic vessels. Twenty-one preparations were imaged from 2 to 48 hours after administration. This method provides a functional demonstration that the tibial and femoral arteries of both species are invested with lymphatics. The first echelon of lymph nodes which drain muscular arteries are imaged within 2 hours. Regional lymph nodes could not be seen to drain the aorta or iliac arteries. Anterior left ventricular myocardial injection in the dog showed a single cardiac lymph node. This drainage pattern has been described previously by other investigators. In the rabbit a similarly placed injection visualized a group of regional cardiac nodes. Ligation of the collecting ducts afferent to the cardiac node in the dog prevented removal of the isotope from the heart at 3, 6, and 9 hours. At 24 hours the liver and spleen were imaged, the radiocolloid gaining entrance to the blood vascular system presumably via myocardial lymphaticovenous anastomoses. Lymphoscintigraphy reflects physiologic processes such as lymph transport, filtration, and reticuloendothelial function. It defines regional patterns of cardiac and arterial lymph drainage. It can confirm experimentally produced impairment of lymph drainage from a defined area of tissue. Lymphoscintigraphy should be useful in the investigation of the significance of lymph drainage to diseases of the heart and blood vessels.

Hemodynamic evaluation of the aortoiliac system based on pharmacologic vasodilatation.

Selection of the appropriate vascular reconstructive procedure in patients with multisegment disease requires the differentiation of aortoiliac from femoropopliteal occlusive disease and the detection of subcritical stenoses in the aortoiliac segment. Triplane arteriography and common femoral intra-arterial papaverine injection (30 mg) were done in 43 lower extremities in patients who subsequently had arterial bypass. The percent diameter stenosis was measured on the arteriograms and common femoral intra-arterial pressure was continuously monitored before and after papaverine injection. A resting femoral/brachial pressure index (FBI) was obtained and the percent decrease in this index (% delta FBI) was calculated using the maximum decrease in FBI following injection. Regression analysis revealed a significant correlation between % delta FBI and percent aortoiliac stenosis (r = 0.5446, P less than 0.005). In relation to clinical course, receiver-operator characteristic curve analysis revealed a % delta FBI of greater than or equal to 0.15 to be optimal in the detection of hemodynamically significant aortoiliac stenoses. When compared to clinical course, this % delta FBI was 88% sensitive, 100% specific, and 95% accurate. However, when analyzed with arteriography as the standard (50% stenosis), the same % delta FBI was only 70% sensitive, 100% specific, and 86% accurate. All limbs with a % delta FBI of 0.15 or greater improved following aortoiliac revascularization; 21% of these limbs had a normal preoperative resting FBI. No patient with a % delta FBI lower than 0.15 had improvement following aortoiliac revascularization. All limbs that had infrainguinal bypass had normal FBIs and % delta FBIs before bypass. After operation 90% of these limbs improved. Overall, this technique correctly predicted the clinical course in 95% of the limbs tested.

Prebypass operative arteriography.

Complete arteriographic delineation of lower extremity arterial anatomy is not always possible preoperatively. Nonvisualization of patent arterial segments may lead to amputation in lieu of arterial bypass grafting. During a 3-year period (1978 to 1981), 31 patients evaluated for lower extremity arterial bypass had incomplete preoperative arteriographic studies. Eighty-seven percent of these patients were in limb salvage categories. In order to obtain better arterial visualization, 33 operative arteriograms, preceding 32 operative procedures, were performed through the femoral (n = 14), popliteal (n = 17), posterior tibial (n = 1), and dorsal pedial (n = 1) arteries. All arteriograms were performed following arterial dissection and clamp occlusion of arterial inflow. The operative arteriogram was found to be beneficial in 91% of cases (29 of 32). In 66%, bypass was performed to vessels that were not visualized preoperatively. In 25%, bypasses were performed to vessels that were visualized preoperatively but intraoperative arteriograms showed better visualization of the vessels and distal runoff, thus allowing bypass to the optimal recipient artery. In three cases (9%), the intraoperative technique was not beneficial, as no additional arterial visualization was provided. Only one patient could not undergo bypass because of nonvisualization of recipient vessels. Overall, major amputation was avoided in 86% of patients (24 of 28) suffering from severe rest pain or gangrene during the period of study. Prebypass operative arteriography is a technique that clearly provides for increased limb salvage. Ninety-three percent of patients (14 of 15) otherwise facing immediate major amputation had their limbs salvaged through the use of this technique.

Intraoperative ultrasonic imaging of the carotid artery during carotid endarterectomy.

Intraoperative real-time B-mode ultrasonography was used to evaluate the technical results of 155 carotid endarterectomies in 143 patients. Technical defects created as a result of the endarterectomy were detected in 43 of the 155 endarterectomies (27.7%) and included intimal flaps (73% of defects); strictures (18%); and arterial kinks, residual plaque, and intraluminal thrombi (9% collectively). Eleven of the 43 endarterectomy sites (7% of all endarterectomies) were reentered to correct a defect; none of these patients had neurologic deficits, which suggests that reentering an endarterectomy and correcting a defect does not, in and of itself, lead to a higher incidence of stroke. The incidence of stroke in patients with normal results of intraoperative ultrasonography was 3.8%, whereas the incidence of perioperative stroke in those patients with insignificant and thus uncorrected defects was 3.3%; this suggests that intraoperative ultrasonography is sufficiently sensitive to detect defects that, when left uncorrected, do not lead to a higher than usual incidence of stroke. Because intraoperative ultrasonography is safe and highly sensitive, we believe it is the method of choice for assessing the technical results of carotid endarterectomy.

The effect of carotid siphon stenosis on stroke rate, death, and relief of symptoms following elective carotid endarterectomy.

It has been suggested that carotid endarterectomy for carotid bifurcation disease may be contraindicated in the presence of carotid siphon lesions. This study was undertaken to assess any difference in stroke rate, mortality, or relief of symptoms in patients with and without such "tandem" lesions following elective carotid endarterectomy. Ninety-one bifurcation endarterectomies were performed in 79 patients. The patients were divided into two groups. Group I (44 patients, 47 endarterectomies) had carotid bifurcation stenosis only; group I (35 patients, 44 endarterectomies) had siphon stenosis plus bifurcation stenosis. All patients in both groups who were symptomatic before operation were relieved of their symptoms. In group I there were no intraoperative or perioperative strokes, four late strokes (8.7%), one operate death (2.1%), and no late deaths. Group II patients had two intraoperative strokes (4.5%), three perioperative strokes (6.8%), two late strokes (5.1%), four operative deaths (9.1%), and three late deaths (7.5%). Eighteen of the 35 patients in group II had a greater degree of carotid siphon stenosis than bifurcation stenosis. In this subgroup, there was one operative stroke (5.6%), only perioperative stroke (5.6%), one late stroke (5.9%), one postoperative death (5.6%), and one late death (5.6%). None of these differences were statistically significant. Relief of symptoms was the same in patients with and without tandem carotid lesions, and there was no significantly increased risk of stroke or death following bifurcation endarterectomy in patients with tandem carotid lesions.

Utility of wide and narrow blood pressure cuffs in the hemodynamic assessment of aortoiliac occlusive disease.

One hundred lower extremities were evaluated by measurement of common femoral intra-arterial pressure and high-thigh Doppler-derived segmental pressures using wide and narrow blood pressure cuffs to assess the accuracy of high-thigh pressures in the evaluation of aortoiliac disease. Sixty-four extremities were also studied by arteriography. The results were analyzed using the common femoral intra-arterial pressure as the standard. The accuracy was poor for both the wide (52%) and narrow (73%) cuff techniques. No significant differences between the two techniques were evident in regard to the incidence of false positive (wide cuff, 75%; narrow cuff, 65%) and false negative (wide cuff, 3%; narrow cuff, 8%) tests. Superficial femoral artery disease was found to be responsible for all false positive tests using the narrow cuff technique (20 of 20) and all but one of the false positive tests using the wide cuff technique (34 of 35). These data indicate that segmental high-thigh pressures are useful primarily as a screening technique (low false negative rate) to exclude hemodynamically significant aortoiliac occlusive disease at rest.

The necessity of mandatory exploration of penetrating zone II neck injuries.

To reevaluate the validity of our policy of mandatory surgical exploration of penetrating zone II neck injuries, the charts of 110 patients who underwent surgical exploration for such injuries were reviewed. Fifty-three percent of the patients had normal findings at exploration, whereas 33% had injuries involving vascular structures of the neck and 14% had nonvascular injuries. Injuries were not suspected on clinical grounds preoperatively in 23% of the patients in whom surgical exploration revealed injury. The injuries most likely to escape preoperative diagnosis were isolated venous injuries and isolated pharyngoesophageal injuries. Arteriography yielded false-negative results in two arterial injuries. No deaths and only a 5% incidence of minor complications occurred in the group with no injuries detected at exploration. We conclude that surgical exploration of penetrating zone II neck injuries is safe and appropriate.

Endotoxin-challenged monkeys and rats.

Studies in our laboratory with both the monkey and the rat showed that, after three hours of endotoxemia, there was a significant decrease in the number of circulating platelets, total hemolytic complement (CH 50 units), and blood serotonin (5-HT) levels. Administration of dexamethasone sodium phosphate in the clinical dose range at the time of endotoxin challenge significantly attenuated the decrease in blood 5-HT levels when compared to the untreated groups in both the monkey and the rat experiments. In the monkey, CH 50 units remained at a higher level when dexamethasone was administered; however, the difference between the treated and untreated groups was not statistically significant. The number of circulating white blood cells and platelets did not appear to be significantly altered by corticosteroid treatment. It is suggested that glucocorticoids may interfere with lipopolysaccharide-induced alterations in complement components or factors regulating hemostasis that influence platelet 5-HT release.

Mandatory vs selective exploration for penetrating neck trauma. A prospective assessment.

To determine the optimal management of patients with penetrating wounds to zone II of the neck, we performed a prospective evaluation of 120 consecutive patients with such injuries, correlating the results of clinical and diagnostic examinations with operative findings. Seven patients presenting with life-threatening hemorrhage from the neck wound were operated on immediately; the remaining 113 patients underwent arteriography, laryngotracheoscopy, esophagoscopy, and esophagography, followed by neck exploration. Forty-eight major injuries were identified in 35 neck explorations. Five patients were identified with clinical and diagnostic findings that were considered normal preoperatively; however, at operation six major injuries were found in these patients. This study indicates that potentially lethal injuries to major vascular and visceral structures in the neck may go undetected if selective exploration criteria are used in the decision to explore penetrating wounds to zone II of the neck.

Ultrasonic imaging during vascular surgery.

Real-time B-mode ultrasound scanning was used during arterial reconstruction surgery to supplement the information of preoperative arteriography and to detect vascular defects immediately after restoration of blood flow. At 55 operations, 100 sites were examined. At three operations, ultrasound provided new information that, in two patients, directly affected the choice of operation. Intraoperative postreconstruction scanning detected vascular defects in over 20% of the patients. Intimal flaps were the commonest defects observed. In most instances in which defects were seen, the vessels were not reentered because the defects were considered to be too small or located in a nonstrategic site or both. One relatively large intimal flap in a common carotid artery prompted reentry. Ultrasound during vascular operations proved to be a highly sensitive diagnostic tool to supplement preoperative arteriography and to detect vascular defects resulting from reconstructive surgery.

Elimination of iatrogenic impotence and improvement of sexual function after aortoiliac revascularization.

One hundred ten men who underwent revascularization for aortoiliac occlusive disease by either aortic reconstruction (n = 66), crossover femorofemoral bypass (n = 38), or axillofemoral bypass (n = 6) were examined with regard to preoperative and postoperative sexual function. Aortic reconstructions were performed using a nerve-sparing technique, and special emphasis was placed on preservation or improvement of pelvic blood supply. Thirty patients (27%) were impotent preoperatively and postoperatively, 67 patients (61%) had normal sexual function preoperatively and postoperatively, and 13 patients (12%) who were impotent preoperatively regained sexual function as a result of revascularization, indicating that 30% (13/43) of all patients with preoperative impotence regained sexual function. No patient with normal preoperative sexual function was impotent postoperatively. Nerve-sparing aortic dissections, attention to preservation or improvement of pelvic blood flow, and, when appropriate, extra-anatomic bypass are essential in the preservation or improvement of sexual function after aortoiliac revascularization.

Early experience with popliteal to infrapopliteal bypass for limb salvage.

In an attempt to improve graft patency and limb salvage in patients with isolated tibial vessel and/or popliteal-tibial vessel occlusive disease, bypass grafts from the popliteal or distal superficial femoral artery to infrapopliteal arteries were used in patients requiring bypass for limb salvage. During a 2 1/2-year period, 23 patients with patent axial vessels and hemodynamically normal inflow to the level of the knee underwent such bypasses. Cumulative graft patency and limb salvage rates at 31 months were 84% and 70%, respectively. Five of the six patients who required below-knee amputation did so because of progressive gangrene in the presence of a patent bypass. Short bypasses between the popliteal and infrapopliteal arteries can significantly contribute to limb salvage in patients with tibial vessel occlusive disease and may be particularly useful in patients with saphenous veins too short for longer bypasses.

Aortic thrombosis after umbilical artery catheterization.

Neonatal arterial thrombosis has become more common with the use of umbilical artery catheters; however, catheter-induced aortic thrombosis is rare. A review of the literature disclosed a 100% mortality from medically managed neonatal aortic thrombosis. Two cases of umbilical artery catheterinduced acute neonatal thrombosis were managed successfully by surgical thrombectomy. Severe lower extremity ischemia and hypertension with aortic occlusion developed in two neonates, and intractable congestive heart failure developed in one of the neonates. This seems to be the first documented report of successful surgical treatment of umbilical artery catheter-induced aortic thrombosis. Acute neonatal aortic occlusion should be considered a surgical emergency.

Crossover femorofemoropopliteal sequential bypass for combined ipsilateral iliac and femoropopliteal occlusive disease.

We evaluated the effectiveness of crossover femorofemoropopliteal sequential bypass in 13 patients with combined ipsilateral iliac and femoropopliteal disease. Of them, eight underwent bypass grafting for limb salvage, and five, for disabling claudication. Four of the patients with claudication had relief of symptoms and significant increases in treadmill walking time. The cumulative limb salvage rate in the patients operated on for limb salvage was 88%. At 42 months, the cumulative patency rate for the femorofemoral portion of the graft was 91%, and for the distal segment, 63%. Mean ankle-brachial indices increased from 0.37 +/- 0.12 preoperatively to 0.76 +/- 0.16 postoperatively in the recipient limb. Early experience suggests that crossover sequential femorofemoropopliteal bypass grafts are effective in achieving limb salvage and relief of claudication, especially in patients with relative contraindications to major intra-abdominal surgery.

Crush syndrome due to limb compression.

Four patients with the crush syndrome due to prolonged limb compression were treated at Cook County Hospital, Chicago. Limb injury was caused when the obtunded patient fell asleep lying on the involved extremity. Prolonged limb compression may cause an acute compartment syndrome with ischemic muscle injury. Continued muscle ischemia may lead to myonecrosis resulting in shock or renal failure. A history of prolonged limb compression with a swollen limb should suggest the diagnosis of crush syndrome. Prompt therapy, including rapid correction of volume and metabolic derangements, extensive open fasciotomy, and dialysis for severe acute renal failure should provide good functional results in the majority of patients.

The natural history of intimal flaps in a canine model.

The natural history of arterial intimal flaps has not been well defined. This study characterizes the natural history of unrepaired intimal flaps. Thirty-nine 1-, 2-, and 3-mm hemispheric, distally based intimal flaps were made in 4- to 5-mm diameter canine femoral and carotid arteries. Twenty arteries had 2- and 3-mm intimal flaps and were monitored for short-term arterial thrombosis and flap extension. Nineteen had 1- and 2-mm intimal flaps and were monitored for thrombosis, long-term development of neointimal hyperplasia, arterial stenosis, and persistence of the flap. While 40% of the arteries with 3-mm intimal flaps developed thrombosis in 3 to 5 days, only 3% of the arteries with 1- or 2-mm intimal flaps developed thrombosis. Most 1- to 2-mm intimal flaps resolved and the subsequent development of neointimal hyperplasia or arterial stenosis was minimal. Arteries with hemodynamically significant stenoses from intimal flaps warrant repair, while arteries with smaller intimal flaps may not require repair.

The treatment of cerebral ischemia by external carotid artery revascularization.

Thirteen patients with internal carotid artery occlusion and symptomatic external carotid artery stenosis underwent external carotid artery revascularization by means of endarterectomy (n = 10) or subclavian artery--external carotid artery bypass (n = 3). All patients but one were followed up, for five to 46 months (mean, 20 months). There were no operative deaths or complications and no late strokes. One patient (7.7%) required early extracranial-intracranial (EC-IC) bypass for failure of the external carotid artery endarterectomy to relieve the initial symptoms. All remaining patients were completely (n = 9) or partially (n = 2) relieved of symptoms, and EC-IC bypass was not required. There were no criteria identified by either oculopneumoplethysmography or angiography that could reliably predict the need for subsequent EC-IC bypass. Ninety-two percent of the patients were adequately treated with external carotid artery revascularization alone, suggesting that subsequent EC-IC bypass is seldom required in patients with ipsilateral internal carotid artery occlusion and external carotid artery stenosis.

Internal iliac artery revascularization in the treatment of vasculogenic impotence.

Five impotent men underwent internal iliac artery revascularization in conjunction with end-to-side aortobifemoral bypass after preoperative testing suggested a vasculogenic cause for impotence. All patients had abnormal preoperative penile/brachial arterial pressure indices (mean, 0.42 +/- 0.12). Following operation, all patients regained erectile capability and had normal postoperative penile/brachial indices (mean, 0.80 +/- 0.06). One patient developed retrograde ejaculation, emphasizing the need for meticulous nerve-sparing dissection with this operation. Internal iliac artery revascularization in conjunction with end-to-side aortobifemoral bypass is effective in relieving vasculogenic impotence in properly selected patients.