Chest roentgenograms in diagnosis of traumatic rupture of the aorta. Observer variation in interpretation.

A significant p value is not always a good measure of the clinical value of a diagnostic test. By examining interobserver agreement with respect to chest roentgenogram interpretation, we determined which of seven roentgenographic signs statistically associated with traumatic rupture of the aorta (TRA) are most likely to be useful in clinical practice. Four surgeons and two radiologists were asked to interpret individually, in blinded fashion, the initial chest films of 149 trauma patients who had undergone aortography to rule out TRA. Agreement between all observers, as well as between specialty groups, was examined by chi-square and by calculation of Cohen's kappa statistic, which estimates the extent of agreement. Statistically significant agreement (p = .0000) was found between all observers with regard to mediastinal widening and obscuration of the aortic knob, but other comparisons showed no better than random agreement. Of the seven roentgenographic signs associated with TRA, identification of mediastinal widening and obscuration of the aortic knob show the most consistent interobserver agreement and are the most likely to be useful in clinical practice.

Noninvasive evaluation of hand circulation before radial artery harvest for coronary artery bypass grafting.

OBJECTIVE: Radial artery harvesting for coronary artery bypass may lead to digit ischemia if collateral hand circulation is inadequate. The modified Allen's test is the most common preoperative screening test used. Unfortunately, this test has high false-positive and false-negative rates. The purpose of this study was to compare the results of a modified Allen's test with digit pressure change during radial artery compression for assessing collateral circulation before radial artery harvest. METHODS: One hundred twenty-nine consecutive patients were studied before coronary artery bypass operations. A modified Allen's test was performed with Doppler ultrasound to assess blood flow in the superficial palmar arch before and during radial artery compression. A decreased audible Doppler signal after radial artery compression was considered a positive modified Allen's test. First and second digit pressures were measured before and during radial artery compression. A decrease in digit pressure of 40 mm Hg or more (digit DeltaP) with radial artery compression was considered positive. RESULTS: Seven of 14 dominant extremities (50%) and 8 of the 16 nondominant extremities (50%) with a positive modified Allen's test had a digit DeltaP of less than 40 mm Hg (false positive). Sixteen of 115 dominant extremities (14%) and 5 of 112 nondominant extremities (4%) with a negative Allen's test had a digit DeltaP of 40 mm Hg or more with radial artery compression (false negative). CONCLUSION: Use of the modified Allen's test for screening before radial artery harvest may unnecessarily exclude some patients from use of this conduit and may also place a number of patients at risk for digit ischemia from such harvest. Direct digit pressure measurement is a simple, objective method that may more precisely select patients for radial artery harvest. Additional studies are needed to define objective digital pressure criteria that will accurately predict patients at risk for hand ischemia after radial harvest.

Attenuation of hemodynamic and hematologic effects of heparin-protamine sulfate interaction after aortic reconstruction in a canine model.

This investigation documented the effect of protamine sulfate pretreatment on the adverse hemodynamic and hematologic sequela of rapid intravenous protamine administration in heparinized dogs having undergone prior implantation of aortic prostheses. Fourteen dogs underwent infrarenal aortic replacement with 6 mm inner diameter by 7 cm knitted Dacron double-velour grafts. Carotid arterial, central venous, and pulmonary arterial catheters were placed for continuous hemodynamic monitoring. All dogs were adequately anticoagulated with heparin (150 IU/kg) and reversed with protamine (1.5 mg/kg/10 sec) after graft insertion. Pretreatment regimens studied included normal saline (n4), protamine 0.75 mg/kg (n5), and protamine 2.25 mg/kg in three divided doses of 0.75 mg/kg each (n5). All pretreatment agents were administered 3 minutes before heparinization. Blood pressure (BP), heart rate (HR), pulmonary artery pressure (PAP) and cardiac output (CO) were measured. Hematologic assessments included platelet count (PC), leukocyte count, thrombin clotting time, and total hemolytic complement. Significant salutory effects were associated with protamine pretreatment regarding BP, HR, PAP, CO, and PC. It is concluded that adverse hemodynamic effects of protamine reversal are blocked and certain hematologic effects are reduced with protamine pretreatment before heparinization and its reversal in this canine experimental model.

Limb salvage by percutaneous transluminal recanalization of the occluded superficial femoral artery.

Six patients with rest pain and gangrene or ulceration were treated by percutaneous transluminal angioplasty using the Grüntzig balloon catheter. All had superficial femoral artery occlusion with severe stenosis or occlusion of the popliteal and tibial arteries. Two patients had previous distal bypass procedures which had failed, and none was a candidate for arterial reconstruction. The superficial femoral artery was recanalized in five patients with an increase in the above-knee pressure index from 0.5 +/- 0.1 to 1.0 +/- 0.1 (P less than 0.001) and ankle pressure index from 0.2 +/- 0.1 to 0.5 +/- 0.1 (P less than 0.001). All five patients avoided early amputation and were able to ambulate when discharged. The sixth patient could not be recanalized and required above-knee amputation. Restenosis of the recanalized superficial femoral artery occurred in four patients 2 to 5 months later, and repeat transluminal angioplasty was successful in three patients. Two patients have required below-knee amputation 4 and 5 months after recanalization. Transluminal angioplasty can extend our capability of early limb salvage.

Prostacyclin treatment of ischemic ulcers and rest pain in unreconstructible peripheral arterial occlusive disease.

The efficacy of prostacyclin (PGI2) treatment was assessed in 26 patients with surgically unreconstructible atherosclerotic arterial occlusive disease of the lower extremity manifested by nonhealing ulcers and rest pain. Patients were randomized to receive a 72-hour intravenous infusion of PGI2 (6 ng/kg/min, n = 13) or placebo (n = 13). Ulcer size was measured by photographic planimetry, and rest pain was graded by blinded objective scoring at monthly intervals for 6 months. Ulcer size increased 64% in PGI2-treated patients and 22% in placebo-treated patients by 1 month after infusion. Rest pain decreased slightly in both PGI2 and placebo groups. At the conclusion of the study, 54% of placebo-treated patients and 31% of PGI2-treated patients had a positive treatment response, indicated by at least a 20% decrease in ulcer size and a 33% decrease in rest pain. PGI2 infusion did not improve the high-placebo response rate seen in these patients with severely ischemic extremities. These results emphasize the importance of placebo-controlled studies, even in patients with unreconstructible arterial disease.

Enhanced patency of small-diameter, externally supported Dacron iliofemoral grafts seeded with endothelial cells.

Fourteen adult foxhounds underwent bilateral iliofemoral bypasses with externally supported, knitted Dacron grafts measured 4 mm in internal diameter and 10 cm in length. These conduits were preclotted with 10 ml of blood mixed with 0.5 ml of culture medium. Autologous endothelial cells, enzymatically derived from external jugular veins, were added to blood and medium used to preclot one graft in each dog. The other, unseeded graft served as a control. Grafts were anastomosed, end to end, to the iliac and femoral arteries. All dogs received dipyridamole, 50 mg twice a day for 4 days preoperatively, and aspirin, 5 grains four times a day for 1 day preoperatively. Both drugs were continued 14 days after operation. Grafts were removed from three dogs at 2 and 4 weeks and from four dogs at 8 and 16 weeks. All grafts were patent at 2 weeks during drug administration. Cumulative patency rates beyond 2 weeks were 73% in 11 seeded grafts and 27% in 11 control grafts, a statistically significant difference (P = 0.03). Seeded grafts were completely surfaced with a monolayer of endothelium between 2 and 4 weeks. Small-graft patency appeared related to evolution of endothelial surfaces, the development of which was clearly facilitated by seeding with autologous endothelium.

Pelvic hemodynamics after aortoiliac reconstruction.

Changes in blood flow to the pelvis were monitored by measurement of penile blood pressures before and after 38 aortoiliac vascular reconstructions. An increase in penile pressure was noted in 14 patients (37%), a decrease was seen in eight patients (21%), and no change occurred in 16 patients (46%). These changes could have been predicted by matching arteriograms to the surgical procedure performed. Preoperative impotence was present in 27 patients (17%). In this group a postoperative increase in penile pressure was associated with restoration of erectile capability in eight of 11 patients. Only one of 10 patients with an unchanged penile pressure regained sexual potency. In contrast, none of the eight patients whose penile pressures decreased had recurrence of erectile capability. Six of these patients had end-to-end aortobifemoral grafts, and concurrent external iliac disease prevented retrograde flow to the internal iliac vessels.

Surgical correction of chronic deep venous insufficiency by valvular transposition.

Twelve limbs in nine patients undergoing venous valve transposition in treatment of severe chronic deep venous insufficiency are the subject of this report. Hemodynamic measurements including venous pressure studies, photoplethysmography, directional venous Doppler assessment, and impedance plethysmography were done pre- and postoperatively in each case, as was ascending and descending venography. The surgical technique is described in detail and diagrams illustrate general features of the reconstruction. The results show that a functioning valve in the deep venous system of the lower extremity may reverse pre-operative pathophysiology. This preliminary view of the operation indicates that it may have great promise in the field of direct venous reconstruction.

Chronic total renal artery occlusion: effects of treatment on secondary hypertension and renal function.

Chronic total occlusion of 42 main renal arteries was documented by arteriographic studies in 25 female and 15 male patients being evaluated for drug-resistant hypertension. Arteriosclerotic lesions affected 35 patients, and fibrodysplastic obstructions occurred in five. Hypertensive urographic studies showed lateralization to the affected kidney in all 31 studies obtained. Renal vein renin activity lateralized with a mean ratio of 3.88 in the 24 patients studied. In 15 patients, mean renal: systemic renin indices (RSRI) of 2.39 confirmed ischemic kidney renin hypersecretion, and a mean RSRI of 0.03 confirmed contralateral suppressed secretion. Affected kidney lengths averaging 9.4 cm were significantly smaller than the 13.0 cm length of kidneys without occluded arteries. Thirty patients with 31 occluded arteries underwent renal artery bypass (18), endarterectomy (2), or nephrectomy (11). There were two perioperative deaths. Eighty-nine percent of survivors benefited in regard to hypertension control, and 47% exhibited improved renal function. Nonoperative treatment of 10 patients was associated with frequent progression of renal failure and inadequate blood pressure control. This experience documents the appropriateness of surgical therapy for secondary hypertension caused by chronically occluded renal arteries.

Treatment of established prosthetic vascular graft infection with antibiotics preferentially concentrated in leukocytes.

The efficacy of treating established vascular graft infections with rifampin and clindamycin (preferentially concentrated in leukocytes) and cefazolin (not concentrated in leukocytes) was studied in a canine model. Infrarenal aortic, 6 mm by 6 cm knitted Dacron double velour grafts were implanted and infected with 10(8) colony-forming units (CFU) of coagulase-positive Staphyloccus aureus organisms injected intravenously immediately after graft placement. Antibiotic therapy was instituted at 3 months postimplantation. Three groups were studied: (I) untreated controls (n = 3); (II) therapy with intravenous cefazolin 15 mg/kg/8 hr for 28 days (n = 7); and (III) combined therapy with intravenous rifampin 13 mg/kg/24 hr and intravenous clindamycin 13 mg/kg/8 hr for 28 days (n = 7). Grafts were removed for quantitative bacteriologic studies after the 28-day course of therapy. Two group I control grafts remained patent with 6.4 X 10(6) and 8.1 X 10(3) CFU S. aureus/gm of graft. The third control graft was thrombosed. Two group II animals demonstrated 1.6 X 10(7) and 2.3 X 10(5) CFU S. aureus organisms/gram of graft, respectively; the remaining five group II grafts were free of organisms. All group III grafts were sterile--a significant difference (p less than 0.05) from group I grafts. In this experimental model, established prosthetic graft infections were eradicated by intensive treatment with antibiotics preferentially concentrated in leukocytes.

Limb-threatening potential of arteriosclerotic popliteal artery aneurysms.

Eighty-eight popliteal artery aneurysms were diagnosed in 59 men and two women (mean age 67 +/- 10 years). Bilateral aneurysms affected 27 patients (44%). Aneurysm diameter ranged from 1.3 to 12 cm (mean 4 +/- 2.6 cm). Most aneurysms were symptomatic (55%). Dominant symptoms included rest pain (19%), claudication (14%), local pain (13%), and gangrene (9%). The remainder of the aneurysms were asymptomatic (45%). Aneurysm thrombosis occurred in 24% of extremities. Associated aneurysms involved the abdominal aorta (62%), iliac artery (36%), and femoral artery (38%). Aneurysms that caused local pain were larger (6.2 +/- 1.9 cm) than asymptomatic aneurysms (2.9 +/- 2.1 cm, P less than 0.01). Aneurysms smaller than 2 cm were more likely to be asymptomatic than larger aneurysms (P less than 0.05). Operative intervention was undertaken for 56 aneurysms, with aneurysmal exclusion or excision with arterial reconstruction performed most often. Four primary and five secondary major amputations were associated with thrombosed aneurysms, compared to no amputations with asymptomatic aneurysms (P less than 0.01). Thirty-two aneurysms were not treated surgically. Limb loss resulted from ischemic complications which developed in 18% of aneurysms treated without operation. The duration of follow-up for patients who had operation and those who did not averaged 62 months and 25 months, respectively. Operative treatment for all bland popliteal artery aneurysms appears justified if complications leading to major amputation are to be avoided.

Abdominal aortic aneurysm rupture: statistical analysis of factors affecting outcome of surgical treatment.

One hundred sixteen patients underwent surgery for ruptured abdominal aortic aneurysms with intraoperative and overall mortality rates of 20.7% and 51.7%, respectively. The correlation of multiple factors to morbidity and mortality was assessed with detailed statistical analysis. Eight preoperative factors were identified as predictors of mortality. Increased intraoperative mortality rates were associated with heart disease (29%), hypertension (30%), flank ecchymoses (57%), and pulsatile abdominal mass (24%). Increased intraoperative and overall mortality rates were associated with preoperative hypotension (39%, 78%) and BUN levels higher than 30 mg/dl (47%, 82%). Increased overall mortality rates were associated with creatinine levels higher than 3 mg/dl (71%) and a hematocrit of 30.0 to 32.5 vol% (75%) (P less than 0.05). Seven intraoperative factors were identified as predictors of mortality. Increased postoperative mortality rates were associated with a duration of operation of more than 400 minutes (100%), hypotension lasting longer than 110 minutes (88%), estimated blood loss more than 11,000 ml (75%), blood transfusion more than 17 U (68%), fluid administration in excess of 7000 ml (70%), and a blood pressure lower than 100 mm Hg at the conclusion of the operation (88%). Cardiac arrest was associated with increased intraoperative and overall mortality rates (77%, 82%) (P less than 0.05). In general these factors cannot be controlled by the surgeon, and future significant reduction in the operative mortality rate may be possible. These findings support the general concept of aggressive elective resection of abdominal aortic aneurysms.

Discriminant arteriographic criteria in the management of forearm and hand ischemia.

Fifty-five patients (33 male and 22 female), 3 to 73 years in age, underwent aortic arch and selective upper extremity arteriography for the evaluation of forearm and hand ischemia from 1971 to 1980. Fifty-one patients had organic occlusive lesions (12 subclavian, 15 axillobrachial, 17 radial-ulnar, and 7 palmar-digital), including distal forearm and hand emboli, as a consequence of proximal occlusive disease in nine patients (5 subclavian, 2 axillobrachial, and 2 radial-ulnar). The remaining four patients had vasospastic disease. Major arteriographic findings of obstructive disease were defined by: morphology of lesions, symmetry or asymmetry of obstructions, segmental versus tandem lesion distribution, and the resultant pattern of collateral circulation. Vasodilatory pharmacoangiography with magnification technique frequently facilitated evaluation of digital and collateral vessels. Therapeutic interventions were dictated by clinical data heavily weighed by the arteriographic examination. Limited arteriographic studies would have been misleading in the evaluation of many patients.

Actuarial analysis of variables associated with rupture of small abdominal aortic aneurysms.

This study identified risk factors associated with rupture of small abdominal aortic aneurysms in patients initially selected for nonoperative management. Sixty-seven patients, 53 men and 14 women, 50 to 91 years of age (mean 72 years) were followed 3 to 99 months (mean 36 months). All patients underwent serial aortic ultrasonography. The annual rate of aneurysm rupture was 6%, with an annual mortality rate caused by rupture of 5% and an annual mortality rate caused by coexistent disease of 6%. Thirty potential risk factors, including blood pressure, aneurysm size measured by ultrasonography, rate of aneurysm expansion, smoking, serum cholesterol levels, and cardiac, pulmonary, and renal risks, were analyzed by Cox proportional hazards regression to identify variables related to rupture. Aneurysm anteroposterior expansion rates varied from 0 to 1.5 cm/year but were not different in aneurysms that ruptured. Only diastolic blood pressure, initial aneurysm anteroposterior diameter, and degree of obstructive pulmonary disease were independently predictive of rupture (p less than 0.05, Wald test). With these data, actuarial rupture rates were predicted for patients with selected values of these three covariates. Predicted 5-year rupture rates varied from 2% when these risk factors were absent to 100% when all three risk factors were significant. Obstructive pulmonary disease, initial aneurysm size, and diastolic hypertension must be evaluated prospectively to assess their accuracy in predicting small aneurysm rupture.

Presentation and perioperative management of arterioportal fistulas.

Arterioportal fistulas (APFs) are usually traumatic in origin and may result in portal hypertension and its complications. Over six years, six patients (aged 20 to 59 years) presented with APFs. Two APFs developed after percutaneous liver biopsy, but only one was complicated (hemobilia). Neither patient was treated operatively. Four APFs occurred two days to three years after gunshot wounds. Three patients presented with gastrointestinal tract hemorrhage. All patients had abdominal bruits. Two patients underwent primary repair. One patient underwent APF resection and replacement of the superior mesenteric artery with autogenous vein. Another patient underwent APF and bowel resection. Three patients survived. One patient died of liver failure. The development of an abdominal bruit in a patient with penetrating abdominal trauma suggests APF and should prompt angiography. Elective repair is recommended before complications of portal hypertension develop.

The effect of sympathetic innervation on canine muscle and skin blood flow.

Two microsphere techniques were used to measure skin and muscle capillary blood flow, plus blood flow through arteriovenous anastomoses (AVAs), before and after unilateral lumbar sympathectomy in 12 anesthetized dogs. Sympathectomy did not alter capillary flow to tibial muscle, thigh, or lower leg skin, whereas paw skin capillary flow decreased, from 28 to 13 mL/min/100 g. However, total extremity blood flow increased after sympathectomy, because of the rate of AVA flow, which increased from 7 to 30 mL/min. Transient nerve stimulation of the cut distal end of the lumbar sympathetic chain immediately and reversibly decreased the AVA flow rate, from 30 to 10 mL/min. The rate of total hind-limb capillary flow also decreased during nerve stimulation, from 86 to 46 mL/min. The only significant effect of sympathectomy in anesthetized dogs was to redistribute distal hind-limb capillary blood flow to AVAs, which are anatomically located in this region. In contrast to capillaries, AVAs have little intrinsic myogenic tone and are highly dependent on adrenergic innervation.

Pediatric vascular trauma. Manifestations, management, and sequelae of extremity arterial injury in patients undergoing surgical treatment.

Twenty pediatric patients with a mean age of 9.2 years exhibited 21 injuries to arteries of an extremity and underwent operation. Included were 12 iatrogenic injuries and nine non-iatrogenic penetrating injuries. Femoral, brachial, popliteal, radial, axillary, iliac, and tibial arteries were sites of vascular trauma. Long-term follow-up, averaging 36 months, was possible in 14 patients. Postoperative scanograms, digital impedance plethysmographic studies, and bone age roentgenograms were routinely obtained. Limb length disparities greater than 5 mm, extremity blood pressure differentials greater than 10 mm Hg, and bone age retardation were encountered. Proper treatment of pediatric patients with acute arterial injuries of an extremity requires early operative intervention and continuous postoperative follow-up during years of active growth. If chronic arterial insufficiency ensues, arteriographic studies should be obtained and arterial reconstruction undertaken.

Intermittent claudication. Current results of nonoperative management.

We reviewed the clinical course of 91 men with mild intermittent claudication who had been followed up for at least six months without operation. During 2.5 years' mean follow-up, 60% of the patients had more severe claudication. Actuarial analysis revealed an annual mortality of 4.5% and an annual operation rate of 9%. Historical factors, including age, race, smoking, exercise, diabetes, hypertension, and the ankle-brachial index (ABI), were analyzed to determine if these variables could predict clinical outcome. Only cigarette smoking, exercise, and the ABI were significant in this regard. Patients who had smoked at least 40 pack-years had an operation rate 3.3 times higher than those who smoked less. Major daily exercise was associated with stable claudication. The initial ABI did not correlate with clinical outcome. A subsequent decrease in the ABI of at least 0.15, however, was associated with an operation rate 2.5 times higher and a symptom progression rate 1.8 times higher than patients without this change in the ABI. When regression analysis was used, the preceding variables were only 63% to 79% accurate in predicting the clinical outcome of individual patients. Careful follow-up of patients with intermittent claudication is therefore recommended to allow timely operative intervention when required.

Extracranial internal carotid artery dissections: noniatrogenic traumatic lesions.

Noniatrogenic traumatic extracranial internal carotid artery dissections were encountered in six patients (five men and one woman) 31 to 62 years old. All but one had overt cerebral ischemia manifest by paresis (three), sensory deficits (three), aphasia (three), or amaurosis fugax (two), One patient had an asymptomatic carotid artery bruit. Cerebral arteriography established the diagnosis in all cases. Internal carotid artery impingement between the mandible and transverse processes of the second and third cervical vertebrae, or undue stretching over these vertebral structures, were the most likely primary mechanisms of injury. Secondary complications, a result of distal thromboembolism, were evident in two patients. Direct cerebral revascularization, staged internal carotid artery constriction and ligation, as well as intensive nonoperative therapy were valid therapeutic options. There were no deaths. Treatment relieved transient ischemic symptoms or arrested progression of established neurologic deficits in each case. In select patients, early surgical intervention may lessen attending neurologic sequelae.

Splanchnic arteriosclerotic disease and intestinal angina.

Twenty-three patients (13 women and ten men, 33 to 73 years old) underwent reconstruction of 33 major splanchnic arteries for relief of symptomatic intestinal ischemia. All patients experienced postprandial abdominal pain and lost weight (average, 12.8 kg). Arterial reconstructions (32 bypass procedures and one endarterectomy with patch-graft arterioplasty) were undertaken with both autogenous saphenous vein (24) and prosthetic condults (nine). Revascularizations involved the superior mesenteric (21), celiac (five), hepatic (four), splenic (two), and inferior mesenteric (one) arteries. There were four postoperative deaths; three occurred after emergent secondary attempts at intestinal revascularization. All of the 19 patients who survived benefited from operative intervention.