Robert W. Barnes

Perioperative asymptomatic venous thrombosis: Role of duplex scanning versus venography * **

We compared combined B-mode/Doppler (duplex ultrasonic scanning and venography in routine preoperative and postoperative screening for major proximal deep vein thrombosis in 78 patients undergoing total hip or knee arthroplasty. Of 309 extremity examinations, duplex scanning had an overall sensitivity of 85.7% (12/14) and a specificity of 97.3% (287/295). The preoperative prevalence and postoperative incidence of major deep vein thrombosis were 2.5% and 14.1% of patients, respectively, despite intensive mechanical and pharmacologic prophylaxis. In addition, venography documented a preoperative prevalence and postoperative incidence of isolated calf deep vein thrombosis in 2.5% and 16.7% of patients, respectively. Whereas such disease extended proximally even in the absence of anticoagulation in only 18% of patients studied by serial duplex scans, calf deep vein thrombosis accounted for the only two instances of pulmonary embolism in this study. There were no deaths related to pulmonary embolism. This study suggests that duplex scanning is useful in screening for perioperative deep vein thrombosis in patients undergoing total hip or knee arthroplasty, which carries a significant risk of venous thromboembolism despite routine prophylaxis.

Thromboembolism in patients undergoing thoracotomy

To determine the incidence of thromboembolism in relation to thoracotomy, 77 patients undergoing pulmonary resection were prospectively studied up to 30 days postoperatively for deep venous thrombosis and pulmonary embolism. Overall, 20 of 77 patients (26%) had thromboembolic events during their hospitalization. Four deep venous thromboses and 1 pulmonary embolism were detected in 5 of 77 patients preoperatively for an incidence of 6%. Postoperative thromboembolism was detected in 15 of 77 (19%): deep venous thrombosis in 11 (14%) and pulmonary embolism in 4 (5%). No postoperative thromboembolisms occurred in the 17 patients receiving preoperative aspirin or ibuprofen, whereas they did occur in 25% of the remainder (15/60). Thromboembolism after pulmonary resection was more frequent with bronchogenic carcinoma than with metastatic cancer or benign disease (15/59 [25%] versus 0/18 [0%]; p < 0.01), adenocarcinoma compared with other types of carcinoma (11/25 [44%] versus 4/34 [12%]; p < 0.0004), large primary lung cancer (> 3 cm in diameter) compared with smaller lesions (9/19 [47%] versus 6/40 [15%]; p < 0.0001), stage II compared with stage I (7/14 [50%] versus 7/34 [21%]; p < 0.04), and pneumonectomy or lobectomy compared with segmentectomy and wedge resection (14/49 [29%] versus 1/28 [4%]; p < 0.005). Three of 4 patients with thromboembolism detected preoperatively had operation within the previous year. Postoperative pulmonary embolism was fatal in 1 of 4 (25%) and accounted for the one death. These results suggest patients undergoing thoracotomy for lung cancer, especially adenocarcinoma, should be considered for thromboembolic prophylaxis.

Mesoaortic compression of the left renal vein (the so-called nutcracker syndrome): Repair by a new stenting procedure

Compression of the left renal vein (LRV) between the superior mesenteric artery and the aorta has been termed the nutcracker syndrome. Although often asymptomatic, this syndrome may result in varicocele, ovarian vein syndrome, and rarely LRV hypertension, pelviureteral varices, hematuria, and flank pain. Previous surgical approaches have included nephrectomy, variceal ligation, nephropexy, or renocaval reimplantation. We report a new LRV stenting procedure that provided relief for a young woman incapacitated by daily left flank pain and microscopic hematuria. Phlebography of the LRV revealed mesoaortic compression associated with a pressure gradient of 12 mm Hg and preferential outflow down large pelviureteral varices. At operation compression of the LRV was corrected with an external stent of reinforced polytetrafluoroethylene. The patient was asymptomatic and free of hematuria for 9 months after operation and follow-up phlebography documented normal renocaval flow, elimination of the pressure gradient, and reduction of the pelviureteral varices. This represents the first description in the vascular surgical literature of this venous compression syndrome, which has been recognized in previous urologic and radiologic reports reviewed herein. Vascular surgeons should be cognizant of the nutcracker syndrome, and we recommend this new stenting procedure as a more simple and physiologic therapy than previous approaches to this problem.

Is routine duplex examination after carotid endarterectomy justified

Routine follow-up of patients after carotid endarterectomy with duplex scanning is commonly practiced, yet the clinical significance of identifying those with asymptomatic restenosis is unclear. To address this issue we reviewed 120 consecutive patients who underwent 143 carotid endarterectomies from August 1983 to December 1988. One hundred one patients (118 operations) were available for clinical follow-up, and the overall incidence of recurrent symptoms was 6% (6/101). Sixty-three of these patients (78 carotid endarterectomies) had postoperative duplex examination. Two had evidence of residual disease from the time of surgery and were not included in further analysis. Significant recurrent stenosis (greater than 50% diameter reduction) developed in 14 of the remaining 76 arteries (18.2%). Twelve of 14 stenoses remained asymptomatic during follow-up from 18 to 72 months (mean 47.0 months) and did not undergo reoperation. Recurrent ipsilateral hemispheric symptoms developed in two patients with restenosis (14.3%). Four of the 62 arteries without significant recurrent stenosis developed ipsilateral symptoms (6.5%), but none required reoperation during follow-up from 1 to 71 months (mean 31.6 months). Life-table analysis showed no increased risk of transient ischemic attack, stroke, or death in patients with restenosis. This study supports regular clinical follow-up after carotid endarterectomy with emphasis on patient education in the recognition of symptoms. Although duplex scanning may be useful to follow known contralateral asymptomatic disease or evaluate those with recurrent symptoms, its routine use to identify patients with asymptomatic restenosis after carotid endarterectomy may be unnecessary.

Late outcome of untreated asymptomatic carotid disease following cardiovascular operations

In a previous prospective study of 449 patients undergoing coronary or peripheral arterial reconstruction, 85 patients had preoperative evidence of asymptomatic bruit and/or greater than 50% carotid obstruction by routine Doppler screening. No patient had prophylactic carotid endarterectomy. This article reviews the late postoperative outcome (2 to 61 months, mean 35 months) of 67 patients with asymptomatic carotid disease who survived operation without perioperative deficit. Eleven patients died (16%) including four of myocardial infarction and two of stroke. Neurologic deficits occurred in the late postoperative period in 22 patients (32.8%) after an average interval of 31 months, including transient ischemic attacks in 15 patients (22.4%); only four of these 15 were appropriate to the side of carotid disease documented preoperatively. Seven patients (10.4%) suffered stroke, only three (4.5%) of which were in the territory of carotid disease detected preoperatively. The cumulative rate of carotid disease progression was 34%, including three patients who suffered carotid occlusion. Two of the latter had the only fatal strokes. This study suggests that patients with asymptomatic carotid disease, although not at significant risk of perioperative stroke, require careful follow-up for late postoperative neurologic deficits, the majority of which (68%) are transient ischemic attacks.

Primary Clostridium septicum aortitis: A rare cause of necrotizing suprarenal aortic infection: A case report and review of the literature

A 74-year old woman sought medical attention for general symptoms of nausea, vomiting, and back pain. A computed tomographic scan showed gas in the wall of the descending thoracic and suprarenal aortas. Emergency thoracoabdominal exploration revealed a necrotizing infection of the thoracic aorta extending to the origin of the celiac axis. After surgery Clostridium septicum was identified in tissue culture. Surgical management consisted of in-situ graft replacement of the thoracoabdominal aorta. Three months later, a pseudoaneurysm developed at the distal anastomosis. The patient refused further surgery and died 3 days later. The cause of death was presumed to be a ruptured mycotic aneurysm as a result of recurrent C. septicum infection. The relationship of C. septicum with occult gastrointestinal and hematologic malignancy has been documented. This patient represents the 10th reported case of C. septicum arteritis. Including the nine previous case reports of C. septicum arteritis, the mortality rate is 70%. When evaluating a patient with a mycotic aneurysm or aortitis, C. septicum should be considered. If it is found, a search should be carried out for an associated gastrointestinal or hematologic malignancy. Surgical repair should include extraanatomic revascularization and wide debridement of the infected field. Consideration should be given to lifelong antimicrobial therapy for this potentially fatal infection.

Angioscopically monitored saphenous vein valvulotomy

Angioscopy was used during in situ saphenous vein bypass grafting in seven patients. We were able to visualize valve incision, immediately identify and correct incomplete valvulotomy, identify side branches as potential arteriovenous fistulas, and assess distal anastomotic integrity. We encountered no retained valve cusps after angioscopy, as verified by Doppler ultrasound and completion angiography. Angioscopy verified distal anastomotic integrity in all patients with distal vein grafts large enough to accept the angioscope. Angioscopy requires minimal time, is relatively easy to use, serves as an adjunct to Doppler ultrasound and completion angiography, and has future potential as a therapeutic tool.

Wound Healing in Forefoot Amputations: The Predictive Value of Toe Pressure

A retrospective study of 136 men undergoing forefoot amputation was done to test the hypothesis that preoperative toe pressure (TP) could predict the likelihood of wound healing. Demographic data included age, smoking history, diabetes mellitus (DM), hypertension, hyperlipidemia, and coronary artery disease. Clinical data included infection, preoperative arterial Doppler data, TP, wound disposition, concomitant revascularization (REV), and healing outcome. Among diabetics, no primary amputation healed with a preoperative TP <38 mm Hg. Among REV diabetics, no healing occurred with a TP <40 mm Hg after bypass, but no failures occurred either with a TP >68 mm Hg or an increase in TP >30 mm Hg after bypass. Nondiabetic patients exhibited no threshold TP values. Univariate analysis revealed that DM and REV were significantly different in the healed (N=83) vs. nonhealed (N=53) populations (p=0.027 and 0.034). In healed patients, mean TP (71.8 ± 3.5 mm Hg SEM) was significantly higher than in nonhealed patients (45.1 ± 4.3 mm Hg SEM,p=0.000). Logistic regression analysis identified age >60 years (p=0.03), DM (p=0.003), preoperative TP (p<0.001), and REV (p<0.001) as significant independent predictors of forefoot amputation healing. Healing probability was calculated and plotted vs. TP for subpopulations based on age, DM, and REV status for both primary forefoot amputation and amputation concomitant with bypass. In this study population, therefore, preoperative TP appeared to be a useful clinical tool for predicting the healing potential of both primary forefoot amputations and amputations plus concomitant bypass for any given patient.

The blue toe syndrome: Hemodynamics and therapeutic correlates of outcome

We reviewed the limb and digit hemodynamics of 67 extremities of 48 patients evaluated for blue toe syndrome in our vascular laboratory during 7 years. These patients represented 1.4% of the arterial examinations during this period. Abnormal ankle/arm pressure indices (less than 0.9), signifying proximal arterial obstruction, were present in 31 limbs (47%). Toe/ankle indices were abnormal (less than 0.6) in 57 extremities (85%), indicating pedal or digital artery obstruction. Arteriograms were obtained in 40 of 64 extremities (63%) available for follow-up, which revealed atherosclerotic disease in 90% (aortoiliac 20%, femoropopliteotibial 30%, and combined 40%), aneurysm in 7.5%, and no disease in only one extremity (2.5%). Of 64 extremities followed for 1 to 84 months (mean, 26 months), only 28 (44%) manifested an uncomplicated outcome. Tissue loss was noted in 24 (38%), recurrent digital ischemia occurred in nine (14%), and 14 limbs (22%) required amputation of toe(s) (seven), forefeet (three) or legs (four). Nine patients (20%) died in the follow-up period. Outcomes did not correlate with limb or digit hemodynamics or with therapy (surgical in 31, medical in 11, or none in 22) except that tissue necrosis was more common in patients undergoing operation. The blue toe syndrome deserves recognition as an important sign of potential limb-threatening arterial disease, but the optimal therapy remains to be established.

Asymptomatic Carotid Disease in Patients Undergoing Major Cardiovascular Operations: Can Prophylactic Endarterectomy Be Justified?

This article reviews the published experience supporting or refuting the value of prophylactic endarterectomy in patients with asymptomatic carotid disease who are candidates for major cardiovascular operations. Reports of 1,483 patients subjected to staged or concomitant carotid endarterectomy and coronary artery bypass grafting reveal a perioperative stroke rate of 2.9%. Timing of carotid endarterectomy did not influence stroke rate, but staged procedures were associated with a significantly greater incidence of perioperative myocardial infarction and death. Studies of patients undergoing major cardiovascular surgical operations without prophylactic carotid endarterectomy reported a perioperative stroke rate of 2.7%, which is not significantly different from that of patients undergoing prophylactic carotid endarterectomy. However, the authors prospective study of such patients showed a significant incidence of late postoperative neurologic deficits, which are usually transient ischemic attacks. There is no evidence to justify routine prophylactic carotid endarterectomy of asymptomatic carotid disease before major cardiovascular operations. Patients not undergoing endarterectomy, however, should be given careful postoperative follow-up, because transient ischemic attacks may occur that require surgical intervention.