Postoperative blood pressure changes associated with cervical block versus general anesthesia following carotid endarterectomy.

The purpose of this report was to determine if cervical block anesthesia (CBA) was associated with fewer hypertensive and hypotensive episodes and decreased need for ICU monitoring following carotid endarterectomy, compared with general anesthesia (GA). A retrospective review of carotid endarterectomies performed using GA (n = 118) versus CBA (n = 116) was carried out and perioperative blood pressure changes and morbidity and mortality rates were analyzed. With increasing emphasis in today's health care market concerning cost containment without sacrificing safety, our results suggest that CBA should be considered preferable to GA for patients undergoing carotid endarterectomy. Fewer significant postoperative hemodynamic changes occurred and costly intensive care monitoring may be avoided.

Five-step protocol for carotid endarterectomy in the managed health care era.

BACKGROUND: We developed a protocol combining 5 cost-effective strategies to determine whether elective carotid endarterectomy (CEA) could be performed safely without adversely affecting well-established low morbidity and mortality rates and with significant hospital cost savings. METHODS: Between April 1, 1995, and December 31, 1996, 109 of 141 patients were prospectively enrolled as candidates into a 5-step CEA protocol: (1) duplex ultrasonography (DU) performed at an accredited vascular laboratory as the sole diagnostic carotid preoperative study, (2) admission the day of operation, (3) cervical block anesthesia to eliminate intraoperative electroencephalogram monitoring, (4) transfer from the recovery room after a 4-hour observation period to the vascular ward, and (5) discharge the first postoperative morning. The other 32 patients were excluded from analysis; 16 patients were treated by vascular surgeons not participating in the protocol, 9 were treated concomitantly for other medical problems, and 7 were admitted emergently. RESULTS: One patient died of carotid hemorrhage the first postoperative morning, and one had an intraoperative embolic stroke for a combined mortality-stroke rate of 1.8% (2 of 109). Of the 109 patients, 70% (76) underwent operation using DU as the sole diagnostic study, 95% (104) were admitted the day of operation, 76% (83) had cervical block anesthesia, 59% (64) were transferred to the floor the day of operation, and 83% (90) were discharged the morning after operation. None of the 109 patients were adversely affected by these 5 cost-saving strategies except potentially the patient who bled the first postoperative morning. The predicted charges of a patient treated with a perioperative protocol that many vascular surgeons currently use (preoperative arteriography, general anesthesia with intraoperative electroencephalogram monitoring, overnight intensive care unit stay, discharge on postoperative day 2) was $16,073 compared with $10,437 for a patient who completed all 5 steps of the protocol detailed above. CONCLUSIONS: On the basis of these results documenting significant cost savings and acceptably low morbidity and mortality rates, this 5-step protocol may be considered the standard for performing CEA in this era of cost containment. These results may be compared with endovascular intervention, which has recently been proposed as a less expensive technique to treat carotid disease.

Do distal arteriovenous fistulae improve patency rates of prosthetic infrapopliteal arterial bypasses?

We retrospectively analyzed if distal anastomotic adjunctive arteriovenous fistulae (AVF) improved patency rates of prosthetic bypasses to infrapopliteal arteries. Between July 1, 1991 and June 30, 1996, we performed 43 polytetrafluoroethylene (PTFE) bypasses to infrapopliteal (19 peroneal, 13 anterior tibial, 11 posterior tibial) arteries. All bypasses were performed for limb salvage when autologous vein was not available for a conduit. Adjunctive AVFs were performed in 21 bypasses (PTFE-AVF) and 22 bypasses did not have a fistula (PTFE-ONLY). Patients were allocated to the PTFE-AVF or PTFE-ONLY groups at the discretion of the surgeons, with adjunctive AVFs being performed for small arteries with poor run-off. There were no significant differences in age, sex, site of the proximal anastomosis, or indication for surgery (p > 0.05). There were statistically significant differences in the site of distal anastomosis and quality of arterial run-off based on the Society for Vascular Surgery Ad Hoc Committee on Reporting Standards criteria (p < 0.05). All patients were placed on heparin 500 units/hour postoperatively, maintained on life-long Coumadin and followed every 3 months with duplex ultrasonography to assess graft patency. Aggressive intervention was carried out for failing grafts suspected by duplex scanning. The hospital mortality rate was 2.3% (1/43; 1 PTFE-AVF). Two-year primary patency rates were significantly better for PTFE-AVF grafts than for PTFE-ONLY grafts (23% versus 5%) (p = 0.04). Although statistical significance was not reached, there was a suggestion of higher assisted primary (34% versus 15%) (p > 0.05) and secondary (61% versus 48%) (p > 0.05) patency rates in the PTFE-AVF group versus the PTFE-ONLY group, although limb salvage rates were similar (74% versus 71%) (p > 0.05). Two AVFs required ligation because of steal resulting in diminished distal perfusion. These results support the use of adjunctive distal AVFs to improve overall two-year patency rates of prosthetic infrapopliteal arterial bypasses.

Selective use of duplex ultrasound to replace preoperative arteriography for failing arterial vein grafts.

PURPOSE: In an effort to minimize costs and patient discomfort, we determined whether duplex ultrasound (DU) could selectively replace preoperative arteriography performed in the radiology suite to diagnose failing arterial bypass grafts (FABs) constructed of autogenous vein. METHODS: Between January 1, 1994, and December 31, 1996, we treated 106 FABs. Graft revision solely on the basis of DU was performed only if a focal stenosis was clearly identified in the graft (peak systolic velocity [PSV] > 300 cm/sec, ratio of adjacent PSVs > 3.0) or in inflow or outflow arteries (resulting in uniform graft PSVs < 45 cm/sec). Intraoperative arteriograms were frequently obtained to confirm DU findings. Preoperative arteriograms were obtained if DU revealed multiple or ill-defined stenoses, diffuse inflow or outflow arterial disease, uniformly low PSVs without an identifiable lesion, or equivocal stenosis despite clinical evidence of an FAB. RESULTS: Seventy-three (69%) FABs with 81 lesions were revised on the basis of DU only. Of 76 stenotic lesions, an intraoperative arteriogram or surgical findings confirmed a diameter stenosis of 75% to 99% in 69 grafts (91%) and stenosis of 50% to 74% in three grafts (4%). DU incorrectly identified the site of stenosis or underdiagnosed the extent of disease in four grafts (5%). DU correctly identified the site of missed arteriovenous fistulas in five grafts. The 73 FABs were treated with intraoperative balloon angioplasty (30 grafts), patch angioplasty (20), interposition or jump grafts (12), ligation of arteriovenous fistula (3), a new bypass graft (1), or a combination of these interventions (7). A significant change in intraoperative strategy potentially could have been avoided if a preoperative arteriogram had been obtained in three of the 73 FABs (4.1%). CONCLUSIONS: DU can reliably be used to revise FABs and avoid the morbidity, discomfort, and cost of confirmatory arteriography in two thirds of cases.

Use of arm and lesser saphenous vein compared with prosthetic grafts for infrapopliteal arterial bypass: are they worth the effort?

PURPOSE: Arm and lesser saphenous veins (ALSVs) are generally considered to be the best alternative for infrapopliteal arterial bypass grafts when greater saphenous vein is not available. The need for additional incisions and repositioning of the patient, along with occasional use of general anesthesia for arm vein harvesting, led to our perception that the use of ALSVs increased operative time and possibly patient discomfort. Therefore, we compared the outcome of ALSVs with that of prosthetic infrapopliteal arterial bypass procedures performed at our hospital. METHODS: Between July 1, 1991, and Dec. 31, 1996, we performed 96 infrapopliteal arterial bypass procedures using 45 ALSVs (28 arm vein, 17 lesser saphenous) and 51 polytetrafluoroethylene (PTFE) grafts. Seventy grafts were single-length ALSV or PTFE bypass grafts, and 26 grafts were placed as the distal segment of a sequential or composite bypass graft. Every attempt was made to use ALSV and avoid the use of PTFE, even if a short segment of the vein graft measured less than 4.0 mm in diameter. There were no significant differences between patients with ALSV compared with PTFE grafts in terms of age, sex, indication for surgery, or number of previous revascularization procedures (2.1 vs 1.7), respectively (p > 0.05). However, ALSV grafts had more factors associated with an expected worse outcome: they were more commonly anastomosed to pedal arteries (17% [8 of 45] vs 0%; p = 0.0009), less commonly single-segment grafts (62% [28 of 45] vs 82% [42 of 51]; p = 0.03), had higher average runoff resistance values (2.3 vs 1.5; p = 0.001), and were less frequently treated with lifelong warfarin (65% [29 of 45] vs 95% [48 of 51]; p = 0.0001). RESULTS: The hospital mortality rate was 3.1% (3 of 96; 3 PTFE). All deaths were cardiac-related. Despite the potential factors associated with worse patency rates for ALSVs, 2-year assisted primary patency rates tended to be higher for arm veins (46%) than for lesser saphenous veins (23%) and PTFE grafts (26%), although this difference was not statistically significant. Limb salvage rates were similar between ALSV and PTFE grafts (76% vs 71%, respectively). The average operative time was significantly longer for ALSV bypass procedures (mean, 6.2 hours) than for PTFE bypass procedures (mean, 4.9 hours; p = 0.003), and for single-length conduits when revision of previously placed grafts was not attempted, the operative time was 4.0 hours for ALSV grafts and 2.5 hours for PTFE grafts. CONCLUSION: In our experience ALSV bypass grafts to infrapopliteal arteries do not function as well as reported by some others. In spite of the extra effort involved, arm vein grafts are preferred over PTFE grafts for their likely higher assisted primary patency rates and equivalent, if not better, limb salvage rates.