Postoperative treatment of patients undergoing carotid endarterectomy

Carotid endarterectomy is a common procedure aimed at the prevention of cerebral vascular accident. Death after carotid endarterectomy is rare (approximately 1%). Postoperative complications occur infrequently (3% to 5%). Myocardial infarction and cerebral vascular accident, two of the most serious postoperative complications, are often associated with changes in blood pressure that occur early in the postoperative period. In addition, cerebral vascular accident often results from thrombosis at the operative site, which may occur during the operation or in the early perioperative phase. Therefore intense monitoring of neurologic and hemodynamic status during the early postoperative period is advocated to control blood pressure and detect changes in neurologic condition. Traditionally, this care is provided in an intensive care unit. Current studies suggest that more than 80% of patients who undergo carotid endarterectomy do not use unique intensive care unit resources; rather, they require monitoring services, which can be safely provided in less intensive alternate settings. This article provides an overview of carotid endarterectomy. Postoperative complications and early (24-hour) perioperative management are reviewed. Alternative strategies to intensive care unit monitoring are proposed.

Failure of thrombolytic therapy to improve long-term vascular patency

PURPOSE

Few data are available on long-term follow-up of arterial segments subjected to thrombolysis. We reviewed all cases of vascular occlusion treated with urokinase to identify early success and determine the influence of postlysis intervention and the nature of the thrombosed segment (i.e., artery vs graft) on long-term patency.

METHODS

Data on 134 cases (58 arteries, 76 grafts) treated with high-dose urokinase infusion in the lower limbs over a 7-year period were analyzed. Limbs were divided into five groups on the basis of therapy after lytic infusion to determine long-term efficacy: group I, success with no additional therapy; group II, percutaneous angioplasty alone; group III, limited surgical procedure (operative angioplasty, jump graft); group IV, extensive procedure (new bypass); and group V, revascularization after lytic failure. Long-term results were assessed by life-table analysis and groups compared by log-rank test (Mantel-Haenszel).

RESULTS

Initial patency was established in 87 (64.9%) of 134 cases with 5 deaths (3.7%), 11 amputations (8.2%), and 16 complications (11.9%). Follow-up was available in 68.6% of cases for a mean of 10.9 months. No difference was seen between grafts and native arteries. Patency was analyzed at 6, 12, 18, and 24 months. The 24-month patency rate after lysis alone (group I-25.9%) was inferior (p < 0.05) to results after lysis and any subsequent intervention (groups II, III, and IV). The type of intervention did not influence subsequent patency. Twenty-four-month patency of procedures performed after failed thrombolysis (group V, 41.4%) was not different from those after successful lysis (groups I to IV). Twenty-four-month patency in groups II and III (minor interventions, 62.9%) was not significantly different from that of groups IV and V (major interventions, 53.2%) (p > 0.25).

CONCLUSIONS

Operative intervention is required to produce long-term arterial patency, even after successful thrombolysis. No statistically significant benefit of thrombolysis on vascular patency was seen in our series.

Early results with cryopreserved saphenous vein allografts for infrainguinal bypass

PURPOSE

Cryopreserved saphenous vein allografts (CSVA) are available for use in arterial reconstructions; however, patency rates in the infrainguinal position are not well described.

METHODS

We reviewed our experience with 38 patients who underwent 43 infrainguinal bypasses with CSVA as the conduit. The group includes 21 women and 17 men with a mean age of 69 +/- 11 years. Mean follow-up is 8.2 +/- 5.5 months. Logistic regression was used to analyze five variables in an attempt to identify predictors of success or failure: distal anastomosis to the popliteal artery versus a crural artery, one-vessel versus two- or three-vessel runoff, postoperative anticoagulation versus none, primary reconstructions versus reoperations, and one segment versus two segments of CSVA required.

RESULTS

The cumulative patency rate at 12 months by life-table analysis is 66%. Logistic regression revealed that primary reconstructions were more likely to succeed than reoperations (p = 0.03) and operations completed with one segment of CSVA were more likely to succeed than those requiring more than one segment of vein (p = 0.03).

CONCLUSIONS

We conclude that (1) the short-term patency of infrainguinal bypasses with CSVA suggests that they may be acceptable alternatives to prosthetic grafts in the below-knee position, and (2) primary reconstructions performed with one segment of CSVA are more likely to succeed.

A prospective, randomized, blinded, and placebo-controlled trial of intraoperative intra-arterial urokinase infusion during lower extremity revascularization. Regional and systemic effects

OBJECTIVE

This study was designed to evaluate the safety and regional and systemic effects of three doses of urokinase (UK) infused into the distal arterial circulation during routine operative lower extremity revascularization.

METHODS

One hundred thirty-four patients were prospectively randomized to receive one of three bolus doses of UK (125,000, 250,000, or 500,000 U) or placebo (saline) infused into the distal circulation before lower extremity bypass for chronic limb ischemia. Regional (femoral vein) and systemic (arm) blood was sampled before drug infusion, prereperfusion, and postreperfusion, and systemic blood samples were obtained 2 hours postreperfusion. Assays evaluated plasma levels of fibrinogen, fibrin(ogen) degradation products (FDP), fibrin breakdown products (D-dimer and fragment B-beta 15-42), and plasminogen. Patients were monitored for clinically evident bleeding complications. The Wilcoxon rank-sum test was used to compare different drug doses with the placebo.

RESULTS

Intraoperative bolus UK infusions produced no significant fibrinogen breakdown compared with placebo. There was a dose-related decline in plasminogen levels, which became significant at a dose of 500,000 U of UK (p < 0.001). There were dose-related increases in plasma FDP, which became significant at dose of 250,000 and 500,000 U (p < or = 0.005), and in plasma D-dimer, which were significant at all UK doses (p < 0.001). The changes in plasma fibrinogen and markers of fibrin breakdown were similar in the regional and systemic circulations. There was no increase in operative blood loss, blood replaced, or wound hematoma formation. There was an unexplained increased mortality in the placebo group (21.1% vs. 2.0%, p = 0.033).

CONCLUSIONS

Intraoperative bolus UK infusion is safe, with no significant fibrinogen depletion or increased operative blood loss or wound hematoma formation. Dose-related plasminogen activation resulted in significant breakdown in cross-linked fibrin in the distal circulation. Intraoperative bolus UK infusion may be valuable as an adjunct in patients with chronic occlusive disease who are undergoing revascularization. Detailed randomized studies are indicated to establish clinical efficacy.

Aneurysmal change at or above the proximal anastomosis after infrarenal aortic grafting

We conducted a retrospective review of all patients undergoing repair of abdominal aortic aneurysm at or above the proximal anastomosis of a previous infrarenal aortic graft between 1986 and 1991. Infected grafts and patients with suprarenal aneurysms present at the time of the original graft were excluded. Twenty-one patients, 19 men and two women, were included. The original indication for surgery was aneurysm in 14 patients and occlusive disease in seven; the mean interval from initial surgery to presentation was 10 years (range, 3 to 23 years). Twelve lesions were anastomotic false aneurysms, and nine were true aneurysms beginning in the proximal juxta-anastomotic aorta. Fourteen patients had an asymptomatic abdominal mass. Seven patients had symptoms of acute expansion (three), rupture (three), or thrombosis (one). True aneurysm and symptomatic presentation were correlated with aneurysm as the original indication for surgery. Repair was accomplished by an interpositional graft in 13 and graft replacement in eight. Seven patients required suprarenal anastomosis or renal and visceral reconstruction. Five operative deaths (24%) occurred, including two of three patients with rupture (67%) and two of seven patients (28%) in the suprarenal group. The mortality rate for elective repair with an infrarenal anastomosis was 11%. Two additional late deaths occurred during the follow-up period.

Late complications of revascularization for radiation-induced arterial disease

During a 14-year period 23 patients underwent 25 revascularizations for radiation-induced arterial obstructive disease. An average of 5000 rads was delivered, 3 to 24 (mean 9) years before arterial insufficiency, for malignancies of the following origin: gynecologic (n = 9), lymphoma (n = 7), head and neck (n = 5), testicular (n = 1), and lower extremity sarcoma (n = 1). Arterial occlusive disease occurred in the aortic arch vessels (n = 8), visceral aortic vessels (n = 1), and aortofemoral vessels (n = 16). Presenting symptoms were claudication (n = 8), rest pain or nonhealing ulcers (n = 7), transient ischemic attacks (n = 6), asymptomatic bruit (n = 1), and renal insufficiency (n = 1). Reconstructive operations included anatomic bypass (n = 10), extra-anatomic bypass (n = 4), patch angioplasty (n = 5), endarterectomy (n = 3), and resection with interposition graft (n = 1). In this group of patients there were no major perioperative wound complications or other major radiation-associated morbidity. Five patients had late graft infections that manifested from 2 to 5 years after surgery. All occurred in anatomic regions where the bypass graft passed through previously irradiated tissues. Presenting symptoms of infection included a draining groin sinus (n = 3) or soft tissue abscess (n = 2). In all cases the graft had not incorporated into the surrounding tissues when passing through the irradiated area. Treatment included graft excision and extra-anatomic bypass through nonirradiated tissue. One patient died of systemic sepsis. Vascular reconstructive surgery can safely be performed for radiation-induced arterial disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Natural history of recurrent and residual stenosis after carotid endarterectomy: implications for postoperative surveillance and surgical management

BACKGROUND

Noninvasive surveillance of patients after carotid endarterectomy is practiced routinely to detect recurrent stenoses. Many authors advocate repair of asymptomatic severe stenoses so detected. The likelihood of these lesions causing neurologic symptoms is unknown. Our aims were to (1) define the incidence of lesions, (2) determine the frequency of associated neurologic symptoms, and (3) identify patient-dependent factors that might predict restenosis.

METHODS

Data on the status of 449 carotid arteries after endarterectomy were reviewed. The number of recurrent and residual severe (greater than or equal to 80%) stenoses was identified. Interval to development of symptoms was determined by life-table analysis. Patient-dependent factors (age, gender, smoking, diabetes, and patch closure) were evaluated by univariate and multivariate analysis to identify possible associations with severe lesions.

RESULTS

Severe (greater than or equal to 80%) stenoses were seen in 35 patients (7.9%). Residual lesions were seen in 17 cases (eight occlusions and nine stenoses); recurrent lesions were identified in 18 patients (3.9%). Symptoms developed in five cases (14%) (one residual and four recurrent) 35, 48, 68, 98, and 103 months after surgery. The likelihood of developing symptoms associated with stenosis at 5 years was 6%. No factors correlated with residual stenosis. Age less than 60 years, female gender, primary closure, and absence of diabetes were more common in patients with recurrent lesions.

CONCLUSIONS

Severe lesions can be found after carotid endarterectomy in at least 8% of patients and consist of residual defects, as well as recurrent stenoses. Recurrent lesions are more common in specific patient subgroups. These lesions are stable for long periods and the majority remain asymptomatic. Operation is not indicated unless symptoms develop in these patients. Intraoperative completion evaluation may be indicated to reduce the incidence of residual disease. Early noninvasive evaluation is useful as a quality-control measure. Repeated surveillance may provide data on the course of restenosis or contralateral disease progression but is of limited clinical benefit.

Donor iliac angioplasty and crossover femorofemoral bypass

We reviewed our experience with 99 patients who had 111 femorofemoral bypass grafts placed over a 10-year period. Mean follow-up was 36 +/- 28 months (range: 1 to 120 months). Bypass alone was performed in 89 cases (group 1). Preoperative donor iliac angioplasty was utilized in 22 cases (group 2). Overall graft failure was 21 of 89 in group 1 and 2 of 22 in group 2 (difference was not significant by chi 2: p greater than 0.05). Clinical success as calculated by life-table analysis was 95%, 83%, 75%, and 67% at 1, 3, 5, and 7 years, respectively, for group 1. Clinical success was 100% and 91% at 1 and 3 years, respectively, and 91% at 42 months for group 2. The success rates were not different for the two groups when analyzed by the log-rank test at 42 months (p greater than 0.30). We conclude that donor iliac angioplasty and femorofemoral bypass is an excellent option for patients with severe occlusive disease of one iliac artery and contralateral disease amenable to angioplasty.

Surgical repair of a celiac axis aneurysm and renal oncocytoma: a single case report

Visceral artery aneurysms are unusual lesions. However the frequency of diagnosis has increased in recent years as a result of increased utilization of arteriogram and computed tomographic (CT) scan. When diagnosed in conjunction with other syndromes, alternative treatment options can be utilized. The present case discusses a 67-year-old black male who presented with a right renal mass and celiac artery aneurysm. The renal mass was diagnosed as an oncocytoma. This unique anatomy enabled us to perform a right nephrectomy in conjunction with a celiac artery aneurysmectomy with primary anastomosis between the right renal artery and common hepatic artery. This case demonstrates our approach to an unusual problem.

Noninvasive assessment of internal thoracic artery for reoperative coronary artery surgery

To determine whether previous sternotomy alters internal thoracic artery (ITA) anatomy and flow characteristics, a duplex scanner was used for noninvasive evaluation of the ITA in 59 patients who were scheduled for reoperative coronary artery bypass surgery. The left ITA was insonated through the third intercostal space by use of a duplex scanner (5.0 MHz probe). Measurements of the ITA diameter (mm) and peak systolic velocity (cm/sec) were obtained; ITA flow was calculated from velocity and cross-sectional area. These findings were compared with the values obtained from 105 patients who were scheduled to undergo first-time (primary) coronary artery surgery during the same time period. In the reoperative group, preoperative mean ITA diameter was 2.26 +/- 0.06 mm; this was not significantly different from the primary group's mean ITA diameter of 2.15 +/- 0.04 mm (p = 0.09). Mean peak systolic velocity was 79.9 +/- 2.4 cm/sec and calculated systolic blood flow was 204.6 +/- 13.1 ml/min in the reoperative patients, as compared with 83.3 +/- 2.1 cm/sec and 189.5 +/- 8.6 ml/min in the primary group, respectively. Values were similar in both groups for the peak systolic velocity (p = 0.31) and calculated systolic blood flow (p = 0.32). These results suggest that previous heart surgery or sternotomy does not adversely affect ITA anatomy and flow characteristics. We conclude that ultrasonic imaging is an easily applicable technique for preoperative assessment of ITA in patients who have undergone previous sternotomy.

Abnormalities in the biosynthesis of type III procollagen in cultured skin fibroblasts from two patients with multiple aneurysms

We examined the synthesis of collagenous proteins by cultured skin fibroblasts taken from 14 patients with an abdominal aortic aneurysm and either an aneurysm at a second site (8 patients) or a first order relative with an abdominal aortic aneurysm (6 patients). Fibroblasts were labeled with [3H] proline and, following pepsin digestion of media proteins, the ratio of type I/III collagen was examined by denaturing polyacrylamide gel electrophoresis (SDS-PAGE). With the exception of two patients, the ratio of type I/III collagen in the media of fibroblasts from aneurysm patients was similar to control values (6 controls). In two of the patients, the type I/III collagen ratio was greater than 3 standard deviations from the mean of both control ratios and those of other aneurysm patients. mRNA levels coding for type III procollagen, however, were normal in both patients. Patient #1 (ME) showed reduced type III procollagen on SDS-PAGE analysis of intracellular proteins. Intracellular and media type III procollagen levels were normal in patient #2 (HR), but media type III collagen was reduced by over 50% after digestion with a combination of trypsin and alpha-chymotrypsin for 5 minutes at 36 degrees C. Control type III collagen was only reduced after digestion at 39 degrees C. These data suggest an altered thermal stability of the type III collagen trimer synthesized by this patient, probably due to a mutation in the amino acid sequence. The data presented in this paper suggest that some forms of common abdominal aortic aneurysms may be caused by mutations in the gene coding for type III procollagen.

Conserving resources after carotid endarterectomy: selective use of the intensive care unit

A retrospective review was undertaken of a random sample (N = 73) comprising 50% of carotid endarterectomies performed during 1986 to evaluate the necessity of routine postoperative intensive care unit (ICU) admission after carotid endarterectomy. Severity of illness was determined with use of the Acute Physiology Score of the APACHE II system. The Therapeutic Index Scoring System was used to quantify postoperative services used. Postoperative morbidity was analyzed. Financial impact was extrapolated with use of 1990 billing data. Length of ICU stay was 24.5 hours. Only 13 of 73 patients (18%) required ICU services. In 10 (77%) of these patients therapy was initiated in the recovery room and discontinued in six patients within 3 hours of ICU admission. Only two patients required ICU services for 16 hours after surgery. The mean Acute Physiology Score was low (4.96) and could not identify patients who required unique ICU services. Neurologic deficits were seen in five patients (6.9%). In three cases deficits were recognized in the recovery room; deficits developed in two patients after discharge from the ICU. Observation in the recovery room with transfer of stable patients would have eliminated ICU admission in 60 patients (82%). In 1990 the incremental ICU charge was $720/patient day. This represents 12.5% of the hospital charges for carotid endarterectomy. The ICU is an expensive and highly used hospital resource. Only a few patients need unique ICU services after carotid endarterectomy, and this is usually apparent within 2 hours of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Ruptured abdominal aortic aneurysms: factors affecting mortality rates

Outcome of 113 operations for ruptured abdominal aortic aneurysms were reviewed to determine the contribution of perioperative events to mortality rates. Preoperative, intraoperative, and postoperative factors were examined with regard to their influence on early and late deaths. A mortality rate of 64% (72/113) was unrelated to age, gender, and preexistent medical conditions. Death within 48 hours occurred in 42 of 72 patients (58%). Preoperative status, including cardiac arrest, loss of consciousness, and acidosis influenced early deaths (less than 48 hours) but not late deaths. Early deaths were also influenced by severe operative hypotension and excessive transfusion requirements. Late deaths (greater than 48 hours) occurred in 30/72 cases (42%) at a mean of 24.6 +/- 22.9 days. Late death was related to postoperative organ system failure, specifically renal and respiratory failure, and the need for reoperation. The overall mortality rate was influenced by preoperative, intraoperative, and postoperative factors. Postoperative renal failure was the strongest predictor of overall deaths. Survival after ruptured abdominal aortic aneurysm depends on intraoperative and postoperative complications as well as preoperative conditions. Late death, the greatest strain on resources, is independent of preoperative status. The thesis that some patients with ruptured abdominal aortic aneurysm should be denied operation to conserve resources is not supported by these data. Efforts to improve survival should focus on reducing intraoperative complications and improving management of postoperative organ failure.

Total excision and extra-anatomic bypass for aortic graft infection

Reports of high mortality and amputation rates following total excision and extra-anatomic bypass for aortic graft infection have prompted the use of alternate approaches including local antibiotics, partial resection, in situ revascularization, and graft excision without revascularization. Experience with aortic graft infection was reviewed to establish current morbidity and mortality rates and evaluate our bias in favor of total excision and extra-anatomic bypass. Aortic graft infection was identified in 32 patients, 8 with aortoenteric fistulas. The mean interval between graft placement and infection was 34 months. History of groin exposure (75%) or multiple prior vascular surgery (50%) was common. Clinical signs included fever and/or leukocytosis (23 patients), false aneurysm (9 patients), graft thrombosis (6 patients), groin infection (11 patients), and gastrointestinal hemorrhage (6 patients). Microbiologic data, available in 26 patients, demonstrated gram-positive organisms in 15 patients and gram-negative in 9. Multiple organisms were seen in 11 patients. Patients were treated by partial removal with (8 patients) or without (4 patients) revascularization or total removal with (18 patients) or without (2 patients) revascularization. Revascularization was by an extra-anatomic route, either simultaneous or staged. Overall morbidity/mortality was less in the revascularized groups (p = 0.01), while late complications were seen only after partial removal (p less than 0.01). The best results were found after total excision with revascularization. No patient in this group experienced late infection or amputation during a mean follow-up of 34 months (range: 1 to 168 months). Complications after total excision and extra-anatomic bypass for aortic graft infection are lower than generally appreciated. This approach should remain the standard to which other approaches are compared.

Surgical treatment of primary aortoduodenal fistula

Primary aortoduodenal fistula is a rare and potentially fatal condition. Awareness of its existence, precise diagnostic evaluation, and early surgical intervention are essential for the survival of the patient. Although early experience indicated that interruption of the fistula, repair of the enteric defect, oversewing of the aorta and extraanatomic bypass was the procedure of choice, in situ aortic replacement with a prosthetic graft seems to be a viable option. This article includes a case report of a primary aortoduodenal fistula and review of the literature.