Biomedical subjects
N R Hertzer
Publications and source records attributed to N R Hertzer.
Reduction in the homologous blood requirement for abdominal aortic aneurysm repair by the use of preadmission autologous blood donation.
BACKGROUND: To evaluate the effectiveness of preadmission autologous blood donation (PABD) in reducing the homologous transfusion requirement of abdominal aortic aneurysm resection, the blood product requirements of 145 patients who underwent operation at Cleveland Clinic from September 1987 through May 1991 were reviewed. METHODS: A study group of 73 patients underwent aortic grafting for aneurysm after PABD. Intraoperative autotransfusion (IAT) was used routinely. Homologous blood requirements were compared to those of 72 patients at the same center who underwent similar operations using IAT alone. No significant differences were noted in age, gender, cardiovascular risk factors, operation complexity, intraoperative blood loss, or IAT volumes between the two groups. Mean aneurysm size of the study patients (5.4 cm) was slightly less than that of the comparison patients (6.0 cm) (p < or = 0.001). Patients in the study group received a mean of 1.9 units predeposited autologous blood. RESULTS: The mean discharge hematocrit (33.4%) and hemoglobin (11.0 gm/dl) levels of the study group were indistinguishable from those of the comparison group (33.3% and 11.1 gm/dl, respectively). The homologous blood requirement of the study group was significantly less (median, 0; mean, 1.3 units/patient) than that of the comparison group (median, 1.5; mean, 1.9 units/patient) (p = 0.001). Furthermore, 67% (49 of 73 patients) of the study group required no homologous blood although only 36% (26 of 72 patients) of the comparison patients avoided banked blood transfusions (p = 0.0004). No significant differences were found in platelet, fresh frozen plasma, or cryoprecipitate requirements between the study and comparison groups. CONCLUSIONS: PABD significantly reduces the homologous blood requirements for elective aortic aneurysm resection and, when used in combination with IAT, eliminates the need for homologous blood in at least two thirds of properly selected patients.
Further developments concerning practice expense reimbursement in vascular surgery.
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Nonoperative treatment of superficial femoral artery disease: long-term follow-up.
PURPOSE: Between 1977 and 1991, 405 patients with atherosclerotic occlusive disease of the superficial femoral artery underwent clinical as well as noninvasive laboratory evaluation and were recommended for nonoperative treatment. METHODS: Limbs with uncorrected aortoiliac occlusive disease, aneurysmal degeneration, or previous femoropopliteal bypass were excluded, leaving 568 involved extremities. Complete follow-up, which forms the basis for this report, was available in 377 patients (93%) with 520 limbs (93%). Patients were monitored for a minimum period of 2 years (range, 24 to 164 months; median, 86 months). During the surveillance period 45 limbs (8.6%) in 42 patients (11.1%) required arterial intervention. This entailed operation in 39 cases and endovascular treatment in six cases. With use of life-table analysis, the risk for intervention was found to be 11% at 5 years and 14% at 10 years. A total of 14 limbs (2.7%) in 14 patients (3.7%) ultimately required major limb amputation, either after failed bypass (8 patients) or as a primary procedure (6 patients). RESULTS: Analysis of risk factors revealed that female sex (p = 0.04), chronic renal failure (p = 0.0001), diabetes mellitus (p = 0.0011), history of contralateral femoropopliteal bypass (p = 0.0005), level of disease (p = 0.003), and entry ankle/brachial index less than 0.50 (p = 0.004) were associated with an increased risk over time for intervention. Other factors, including age, current or prior smoking history, hypertension, and the presence of coronary artery disease or cerebrovascular disease failed to reach statistical significance. CONCLUSIONS: These data support the continued conservative approach to surgery for patients with superficial femoral artery occlusive disease without limb-threatening symptoms. Patients with multilevel disease, lower ankle/brachial index, a history of contralateral femoropopliteal bypass, chronic kidney failure, or diabetes mellitus are at increased risk and should be monitored more closely.
The resource-based relative value scale in vascular surgery. A report of the activities of the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery in Medicare reimbursement reform.
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Surgical management of aortic aneurysm and coexistent horseshoe kidney: review of a 31-year experience.
PURPOSE: The coexistence of horseshoe kidney and aortic aneurysm poses a technical challenge to the vascular surgeon at the time of aneurysm repair. Clinical experience with this problem was reviewed to assess the results of treatment and to develop guidelines for the treatment of patients with horseshoe kidney and aortic aneurysm. METHODS: From 1960 through 1991, 19 patients with associated horseshoe kidney (HSK) required repair of abdominal aortic aneurysm at the Cleveland Clinic. Seventeen men and two women, with a mean age of 67 years, underwent 16 elective and three urgent operations. The HSK was found before operation in 16 patients (84%), whereas the remaining three were discovered at operation. Computed tomography and intravenous pyelography were the most reliable means of preoperative diagnosis, whereas ultrasonography and aortography were less dependable. Mean size of abdominal aortic aneurysm was 6.1 cm. The mean preoperative creatinine level was 1.5 mg/dl. The surgical approach was transperitoneal in 16 patients and retroperitoneal in three. Division of the renal isthmus was avoided in all patients. RESULTS: Renal artery anomalies were encountered in 14 patients (74%). Renal arterial continuity was established by a variety of techniques, including branch grafts or reimplantation into the aortic graft. Abnormal preoperative renal function was associated with a significantly increased risk for early postoperative hemodialysis (p = 0.02). There were three postoperative deaths, and the mortality rate for patients who required dialysis (67%) was significantly higher (p = 0.05) than that for patients who did not (6.3%). There were six late deaths at a mean follow-up interval of 57 months. CONCLUSIONS: The most important aspect of HSK, therefore, is the appropriate surgical management of frequent renal artery anomalies. We currently believe this is best achieved with retroperitoneal exposure.
Saphenous vein patch rupture after carotid endarterectomy.
From January 1983 to September 1990, 2731 carotid endarterectomies were performed at The Cleveland Clinic. Patch angioplasty with autogenous saphenous vein was used for arteriotomy closure during 1691 (62%) of these procedures and was associated with eight postoperative ruptures (0.5%) of the central portion of the patch in seven patients. This complication occurred in three men and in four women (mean age, 69 years), all of whom were hypertensive and all but one were smokers. Two patients (29%) had diabetes. In each case of patch rupture the vein had been harvested from the leg distal to the knee. Although the harvest site could not be determined retrospectively for every patient in this series, no patch ruptures were encountered among 370 procedures for which it could be documented that the saphenous veins had been obtained from the groin. All ruptures occurred within 5 days of the primary operations (including four during the first 24 hours) and were urgently corrected by primary closure of the original arteriotomy in two cases and by replacement of the ruptured patch in the remaining six. Two (29%) of the seven patients either died or sustained a permanent neurologic deficit. Central rupture of a saphenous vein patch is a rare but devastating complication after carotid endarterectomy. Since vein harvested from the lower leg or ankle may be marginally more likely to rupture than proximal vein from the thigh or groin, it should not be used indiscriminately for carotid patch angioplasty.
Cephalic vein grafts for lower extremity revascularization.
From 1980 to 1989 infrainguinal revascularization was performed with cephalic vein grafts in a consecutive series of 34 patients (35 limbs) whose saphenous veins were either inadequate or already had been harvested for previous coronary (N = 16, 47%) or ipsilateral lower extremity bypass (N = 19, 56%). Surgical indications included ischemic rest pain or focal tissue necrosis in 25 limbs (71%), disabling claudication in six (17%), and popliteal aneurysms or prosthetic femoropopliteal graft infections each in two (6%). Preliminary arteriovenous fistulas were constructed in the arms of 23 patients (68%) to enhance the diameter of their cephalic veins, and 24 (69%) of the 35 infrainguinal procedures in this series were performed with use of cephalic vein alone. The distal popliteal artery was used for the outflow anastomosis in 10 limbs (29%), a tibial vessel was used in 12 (34%), and the peroneal artery was used in 13 (37%). Fourteen graft occlusions (40%) and six amputations (17%) have occurred during follow-up intervals of 1 to 107 months (mean, 28 months; median, 27 months). At 3 years the cumulative primary patency rate is 40%, the secondary patency rate is 46%, and the limb salvage rate is 82%. Despite their relative inconvenience, cephalic vein grafts appear to be preferable to prosthetic materials for infrainguinal revascularization below the knee.
Thoracoabdominal aneurysm repair: a representative experience.
Between May 1966 and June 1991, 129 patients underwent surgical repair of thoracoabdominal aneurysms, with an overall 30-day mortality rate of 35%. In 75 operations (58%) performed electively, 11 deaths (15%) occurred, and in 54 cases (42%) of either symptomatic or ruptured aneurysms 34 deaths (63%; p less than 0.001) occurred. No one survived among six patients with preoperative hypotension (less than 90 mm Hg) or cardiac arrest. In 16 patients (12%) the etiology of aneurysms was a result of chronic aortic dissection, and the mortality rate in this subgroup was 44%. In the remaining 113 patients (88%) where the etiology was atherosclerosis, 38 deaths occurred (34%; p = 0.433). Spinal cord ischemia occurred in 25 cases (21%) among 116 patients who survived operation. Partial ischemia occurred in six cases (25%), and complete paraplegia occurred in the remainder. Complete and partial paraplegia occurred in 16 of 42 cases (38%) when all of the thoracic aorta was replaced (Crawford groups I, II) and in 9 of 74 cases (12%) when only the abdominal or lower thoracic aorta was replaced (Crawford groups III, IV; p = 0.016). Other complications included myocardial infarction (14 cases, 11%), respiratory failure (46 cases, 36%), and renal failure (33 cases, 27%). The major prospect for improved early survival of patients with thoracoabdominal aneurysms seems to be early detection and elective repair before the occurrence of symptoms.
The natural history of peripheral vascular disease. Implications for its management.
The durability and the eventual complication rate of endovascular therapy (percutaneous transluminal angioplasty, laser-assisted angioplasty, and atherectomy) are not yet entirely clear, especially with respect to the treatment of atherosclerotic lesions in the femoropopliteal or distal arterial segments. Therefore, the indications for its use have not been firmly established and must take into consideration the natural history of the occlusive disease itself. Although some type of procedural intervention clearly is warranted in the presence of ischemic rest pain or tissue necrosis, intermittent claudication is the only complaint in approximately 70% of patients who present with either aortoiliac or femoropopliteal involvement. Most nondiabetic patients experience substantial symptomatic improvement with a daily exercise program, and their long-term risks for either abrupt deterioration (20-25%) or amputation (less than 10%) are relatively low. In comparison, the 5-year mortality rate ranges from 20-40% even in claudicants, and as many as 40% of those with clinical indications of associated coronary artery disease have been shown angiographically to be candidates for myocardial revascularization. These observations suggest that traditional indications for surgical treatment (truly disabling claudication and/or limb salvage) also should be applied to endovascular therapy until its success is confirmed beyond speculation, and that incidental coronary disease deserves particular attention in patients with lower extremity ischemia.
Surgical treatment of brachial artery injuries after cardiac catheterization.
A consecutive series of 532 patients (1.5%) required local thrombectomy and arterial repair after 34,291 transbrachial cardiac catheterizations performed at the Cleveland Clinic from 1980 to 1988. A total of 514 patients (97%) were discharged from the hospital with normal radial pulses and/or normal ulnar pulses after a single surgical procedure. Fourteen others (3%) each required one additional procedure to regain a distal pulse, and four patients either underwent two reoperations, received thrombolytic therapy, and/or remained pulseless. Surgical delay of more than 1 day after catheterization was associated with a higher incidence of recurrent thrombosis (12% vs 2%, p = 0.025). In comparison to our previous experience with iatrogenic brachial injuries, the liberal use of segmental arterial resection and overnight heparin anticoagulation seem especially to reduce the risk for early failure in all patients, but improvement was particularly marked in women (25% vs 6%, p = 0.0004).
Guidelines for hospital privileges in vascular surgery.
This is a report by an ad hoc committee to the Joint Council of the Society for Vascular Surgery and the International Society for Cardiovascular Surgery (North American Chapter) concerning guidelines that hospitals may use or modify when judging individual applicants for hospital and operating room privileges in vascular surgery. The committee recognizes that the completion of training and obtaining a board certificate is testimony to the qualification but not necessarily the competence of an individual to practice vascular surgery. This report identifies three categories of applicant for privileges in vascular surgery; the surgeon who just completed training, the surgeon who completed training after 1984, and the surgeon who completed training before 1984. In addition, the committee recognizes the importance of periodic vascular surgery privileges renewal for established surgeons. Several pathways are defined for use by hospital privilege committees to evaluate the competence of an individual to be granted privileges in general vascular surgery. The ad hoc committee also has outlined a program for evaluation of established surgeons for renewing privileges in vascular surgery using a mechanism of case outcome audit. Finally, a review mechanism, potential corrective actions, and an appeals mechanism are also suggested. This report represents optimal criteria that may require modification by individual hospitals to meet local community needs and standards. It is the hope of the ad hoc committee that this report will help hospitals and practicing physicians improve the quality of care and treatment outcome in patients with vascular disease.
Surgical staging for simultaneous coronary and carotid disease: a study including prospective randomization.
Simultaneous carotid disease was documented in 275 (2.8%) of 9714 patients scheduled for coronary artery bypass (CAB), including 80 (29%) who had had previous neurologic events and 195 with severe (greater than or equal to 70% diameter), asymptomatic carotid stenosis. Preliminary carotid endarterectomy (CE) was feasible before CAB in only 24 patients with stable cardiac disease (group I). Another 129 patients with unstable disease (group II) had unilateral, asymptomatic carotid lesions and were prospectively randomized to receive either combined operations (IIA; n = 71) or CAB followed by delayed CE (IIB; n = 58). The remaining 122 patients (group III) had symptomatic or bilateral carotid stenosis and were managed on a selective basis without randomization. The operative mortality rate ranged from 4.2% to 5.2%, and the early stroke rates were 4.2% in group I, 7.8% in group II, and 11% in group III. Postoperative strokes occurred after CAB in nine (4.7%) of the 193 patients protected by preliminary or simultaneous CE, compared with six (7.4%) of the 81 who received only delayed CE. Nevertheless, the composite stroke risk for "reverse-staged" procedures in group IIB (14%) exceeded that for combined operations (2.8%) in group IIA (p = 0.045). The stroke rate was 11% (7/61) when delayed CE was performed within 2 weeks after CAB compared with 2.2% (1/46) with longer staging intervals.
Carotid endarterectomy in a metropolitan community: the early results after 8535 operations.
Several retrospective community surveys have provoked speculation concerning the safety of carotid endarterectomy (CEA) throughout the United States. To address this serious issue, surgical outcome was calculated for 8535 CEAs entered prospectively into a computer registry by 51 trained vascular surgeons in a large metropolitan area from 1973 to 1985. A total of 7480 procedures (88%) were performed for symptomatic lesions and 1055 (12%) were performed for asymptomatic stenosis or ulceration. There were 178 operative strokes (2.1%) and 135 early deaths (1.6%), for a combined morbidity-mortality rate of 3.2%. Fatal events were attributed to cardiac disease in 0.7%, neurologic complications in 0.6%, and other causes in 0.3%. The stroke rate (n = 148; 2.0%) in symptomatic patients was better than that in asymptomatic patients (n = 30; 2.8%) (chi 2 = 5.2; p less than 0.025), but the combined morbidity-mortality rates (2.9% and 3.7%) were not statistically different. The incidence of stroke reported by surgeons who performed more than 5 CEAs annually (1.7%) was statistically superior to the stroke rate (3.4%) among those with less experience (chi 2 = 37.1; p less than 0.0001). Nevertheless, both groups had acceptable results that were consistent with their training and continued interest in vascular surgery.
Late patency of the carotid artery after endarterectomy. Problems of definition, follow-up methodology, and data analysis.
To determine the relative incidence of recurrent carotid stenosis (RCS) and the effect of methodology on data analysis and interpretation, late results were obtained for 232 patients (270 procedures) from 1 to 51 months (mean 22 months) after carotid endarterectomy (group A). Patency of the carotid artery was confirmed by postoperative intravenous digital subtraction angiography (DSA) for most of the series, and a subset (subgroup A1) of 113 patients (129 procedures) also received DSA studies at later intervals of 4 to 49 months (mean 26 months). There were 23 late deaths and five late strokes. Only two of the strokes were ipsilateral to previous endarterectomy, and both of these patients had normal follow-up DSA studies. Late DSA imaging revealed either no RCS or only trivial defects (20% diameter or less) in 111 arteries, moderate (36% to 60%) RCS in nine, severe (70% to 90%) RCS requiring secondary procedures in eight, and internal carotid occlusion in one. Depending on the definition of RCS (secondary operation vs greater than or equal to 30% angiographic lesions), the cohort selected for analysis (group A vs subgroup A1), and the approach to calculations (crude vs cumulative), the incidence of recurrent stenosis after carotid reconstruction in this single study could be expressed within the extraordinary wide range of 3% to 32%. Although carotid endarterectomy was associated with uniformly low risk for late stroke, these results confirm that the reported recurrence rate may be substantially influenced by the method in which data are grouped and manipulated. Consistently presented data are essential to any comparisons concerning the surgical therapy for extracranial disease.
Thrombolysis of peripheral arterial bypass grafts: surgical thrombectomy compared with thrombolysis. A preliminary report.
Twenty-two patients were selected from a group of 33 patients who underwent recombinant human tissue-type plasminogen activator (rt-PA) thrombolysis for thrombosed infrainguinal bypass grafts of the lower extremity and were compared with 38 matched patients who had undergone surgical thrombectomy during the same period. The proportion of persons with diabetes mellitus, smokers, and types of bypass grafts was similar in both groups. More patients in the rt-PA-treated group had hypertension (p = 0.01). To evaluate the different lengths of follow-up, Kaplan-Meier survival analysis was used with a log-rank test to compare the proportion of persons with patent grafts in the two treatment groups. At 30 days, 86% of the rt-PA-treated grafts were still patent compared with 42% of the surgically treated grafts (p = 0.001). When risk factors on the Kaplan-Meier curves were compared, there was no statistical difference with regard to graft patency among the groups. According to simultaneous Cox regression analysis, no risk factor was significantly associated with graft patency. When amputation was evaluated between treatment groups simultaneously with other risk factors in a logistic regression analysis, smoking and age of the graft were marginally significant (p = 0.07), whereas all other factors were clearly not significant. In 91% of the rt-PA-treated patients, a secondary surgical procedure was required to maintain patency of the graft segment. Eighty-nine percent of the surgically treated patients required similar graft revisions. Two patients in the surgical group and one patient in the rt-PA-treated group had major complications.(ABSTRACT TRUNCATED AT 250 WORDS)
Carotid endarterectomy--a crisis in confidence.
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Late results of coronary bypass in patients presenting with lower extremity ischemia: the Cleveland Clinic Study.
Cardiac catheterization was performed in a prospective series of 1000 patients under consideration for elective peripheral vascular reconstruction from 1978-1982. Of these, 381 (mean age 62) presented primarily because of lower extremity ischemia. Severe, surgically correctable coronary artery disease (CAD) was documented in 79 (21%) of the leg group, and 68 (18%) received myocardial revascularization, with three fatal complications (4.4%). In this subset, 39 patients have had uneventful aortoiliac, femoropopliteal or distal extremity procedures, compared to an operative mortality of 23% for 13 others with uncorrected or inoperable CAD (p = 0.015). A total of 286 patients have undergone 407 peripheral vascular operations with eight early deaths (2.8%). An additional 114 patients (30%) died during the late follow-up interval, including 48 (13%) with cardiac events. Both the cumulative 5-year survival (72%) and cardiac mortality (16%) after coronary bypass are superior to comparable figures (21% and 56%, respectively) among 36 other patients with severe, uncorrected or inoperable CAD (p = 0.0001). Five-year survival appears to be improved by myocardial revascularization in men (p = 0.0027), hypertensives (p = 0.0001), nondiabetics (p = 0.0002) and those over 60 years of age (p = 0.0072).