Simultaneous aortic replacement and renal artery revascularization: the influence of preoperative renal function on early risk and late outcome.

PURPOSE: We documented the postoperative complication rate and the late results of simultaneous infrarenal aortic replacement and renal artery (RA) revascularization at the Cleveland Clinic and correlated these findings with the preoperative serum creatinine level (S(Cr)) and other baseline risk factors. METHODS: A retrospective review of hospital charts and outpatient records was supplemented with a telephone canvass and the invitation to return for a complimentary RA duplex scan, when a scan had not been done within the previous year. Data were collected for 73 consecutive patients (mean age, 69 years) who underwent aortic procedures that were combined with the repair of RA stenosis from 1989 to 1997 (mean follow-up, 44 months). The preoperative S(Cr) was 2 mg/dL or lower in 45 patients (group R1; median, 1.5 mg/dL) and was higher than 2 mg/dL in the remaining 28 patients (group R2; median, 2.6 mg/dL). RESULTS: Forty-seven of the patients in this series had aortic aneurysms, 15 patients had aortoiliac occlusive disease, and 11 patients had both types of lesions. Bilateral RA revascularization was necessary for seven patients in group R1 (15%) and for eight patients in group R2 (29%). Group R2 contained more patients with medically resistant hypertension (57%) than group R1 (29%, P = .019). Although there was no statistically significant difference between the 30-day mortality rates (group R1, 2.2%; group R2, 11%), the related in-hospital mortality rate for 15 bilateral RA revascularizations (13%) was nearly twice that of 58 unilateral revascularizations (6.9%). Patients in group R2 were at a higher risk for postoperative dialysis than those in group R1 (36% vs 6.7%, P = .008), and patients in group R2 had longer lengths of stay in the hospital (median, 14 days vs 9 days; P = .004). By means of Kaplan-Meier analysis, the 5-year survival rate was lower for patients in group R2 (53%; 95% CI, 33%-73%) than for patients in group R1 (85%; 95% CI, 74%-96%; log rank P = .005). Despite all other liabilities in group R2 patients, however, their resistant hypertension was cured or improved in 88% of cases and their S(Cr) appeared to decline with time. CONCLUSION: The early postoperative risk of simultaneous aortic/RA procedures appears to be highest in patients who have an elevated S(Cr), bilateral RA stenosis or occlusion, and a comparatively low long-term survival rate. In this particular group, the adjunctive use of endovascular techniques might conceivably reduce the magnitude of the planned surgical procedure and thus enhance the overall outcome.

Reoperation for recurrent carotid stenosis: early results and late outcome in 199 patients.

PURPOSE: This study was undertaken to determine the safety and efficacy of reoperations for recurrent carotid stenosis (REDOCEA) at the Cleveland Clinic. MATERIALS AND METHODS: From 1989 to 1999, 206 consecutive REDOCEAs were performed in 199 patients (131 men, 68 women) with a mean age of 68 years (median, 69 years; range, 47-86 years). A total of 119 procedures (57%) were performed for severe asymptomatic stenosis, 55 (27%) for hemispheric transient ischemic attacks or amaurosis fugax, 26 (13%) for prior stroke, and 6 (3%) for vertebrobasilar symptoms. Eleven REDOCEAs (5%) were combined with myocardial revascularization, and another 19 (9%) represented multiple carotid reoperations (17 second reoperations and 2 third reoperations). Three REDOCEAs (1%) were closed primarily, and nine (4%) required interposition grafts, whereas the remaining 194 (95%) were repaired with either vein patch angioplasty (139 [68%]) or synthetic patches (55 [27%]). Three patients (2%) were lost to follow-up, but late information was available for 196 patients (203 operations) at a mean interval of 4.3 years (median, 3.9 years; maximum, 10.2 years). RESULTS: Considering all 206 procedures, there were 7 early (< 30 days) postoperative neurologic events (3.4%), including 6 perioperative strokes (2.9%) and 1 occipital hemorrhage (0.5%) on the 12th postoperative day. Seventeen additional neurologic events occurred during the late follow-up period, consisting of eight strokes (3.9%) and nine transient ischemic attacks (4.4 %). With the Kaplan-Meier method, the estimated 5-year freedom from stroke was 92% (95% CI, 88%-96%). There were two early postoperative deaths (1%), both from cardiac complications after REDOCEAs combined with myocardial revascularization procedures. With the Kaplan-Meier method, the estimated 5-year survival was 81% (range, 75%-88%). A univariate Cox regression model yielded the presence of coronary artery disease as the only variable that was significantly associated with survival (P =.024). The presence of pulmonary disease (P =.036), diabetes (P =.01), and advancing age (P =.006) was found to be significantly associated with stroke after REDOCEA. Causes of 53 late deaths were cardiovascular problems in 25 patients (47%), unknown in 14 (26%), renal failure in 4 (8%), stroke in 3 (6%), and miscellaneous in 7 (13%). CONCLUSIONS: We conclude that REDOCEA may be safely performed in selected patients with recurrent carotid stenosis and that most of these patients enjoy long-term freedom from stroke.

Preprocedural risk stratification: identifying an appropriate population for carotid stenting.

PURPOSE: Given the uncertainties associated with carotid angioplasty and stenting, the initial assessment of the procedure may be best undertaken in a subgroup of patients at increased risk for complications with standard carotid surgery. In an effort to characterize such a subgroup, we reviewed the results of carotid endarterectomy in patients with and without significant medical comorbidity. METHODS: During a 10-year period 3061 carotid endarterectomies were performed at a single institution and entered prospectively into a registry. A high-risk patient subgroup was identified, defined by the presence of severe coronary artery disease, chronic obstructive lung disease, or renal insufficiency. The outcome of carotid endarterectomy was assessed with respect to perioperative stroke, myocardial infarction, or death, as well as the combined end point of one or more of the end points. RESULTS: The rate of the composite end point stroke/myocardial infarction/death was 3.8% in the total group of 3061 patients who underwent endarterectomy. As individual end points, the rate of stroke was 2.1%, myocardial infarction 1.2%, and death 1.1%. Among the high-risk subset, the composite end point stroke/myocardial infarction/death occurred in 7.4%. This rate was significantly greater than the corresponding rate of 2.9% in the low-risk subset (P <.0005). Similarly, the rate of stroke (3.5% vs 1.7%, P =.008) or death (4.4% vs 0.3%, P <.001) as solitary events was significantly greater in high-risk patients. CONCLUSIONS: Although carotid endarterectomy is an extremely safe procedure in most patients, results are not as favorable in a high-risk subset with severe coronary, pulmonary, or renal disease. The initial clinical evaluation of carotid stenting might best be undertaken in such a high-risk population, one that comprises patients for whom standard therapy is associated with a high rate of complications.

Chronic mesenteric ischemia: open surgery versus percutaneous angioplasty and stenting.

OBJECTIVE: The aim of the study was to evaluate the safety and efficacy of percutaneous angioplasty and stenting (PAS) in comparison with traditional open surgical (OS) revascularization for the treatment of chronic mesenteric ischemia. METHODS: Over a 3.5-year period, 28 patients (32 vessels) underwent PAS (balloon angioplasty alone, 5 [18%] of 28; angioplasty and stenting, 23 [82%] of 28) for symptoms of chronic mesenteric ischemia. These patients were compared with a previously published series of 85 patients (130 vessels) treated with OS (bypass grafting, 60 [71%] of 85; transaortic endarterectomy, 19 [22%] of 85; or patch angioplasty, 6 [7%] of 85). RESULTS: The PAS and OS groups were similar with respect to baseline comorbidities, duration of symptoms (median: 6.7 vs 10.5 months, P =.52), and the number of vessels involved, but the patients differed in their age at presentation (median: 72 vs 65 years, P =.005). Fewer vessels were revascularized per patient in the PAS group (1.1 +/- 0.4) compared with the OS group (1.5 +/- 0.6, P =.001). Overall, 85.7% (24/28) had one vessel and 14.3% (4/28) had two vessels revascularized in the PAS group versus 48.2% (41/85) with one-vessel and 47.1% (40/85) with two-vessel revascularization in the OS group. No difference was noted in the early in-hospital complications (median: 17.9% [PAS] vs 32.9% [OS], P =.12) or mortality rate (10.7% [PAS] vs 8.2% [OS], P =.71). A reduced length of hospital stay in the PAS patients did not attain statistical significance (median: 5 days [PAS] vs 13 days [OS], P =.08). Although the 3-year cumulative recurrent stenosis (P =.62) and mortality rate (P =.99) did not differ, the PAS treatment group had a higher incidence of recurrent symptoms (P =.001). CONCLUSION: Although the results of PAS and OS were similar with respect to morbidity, death, and recurrent stenosis, PAS was associated with a significantly higher incidence of recurrent symptoms. These findings suggest that OS should be preferentially offered to patients deemed fit for open revascularization.

Construction of a high affinity zinc binding site in the metabotropic glutamate receptor mGluR1: noncompetitive antagonism originating from the amino-terminal domain of a family C G-protein-coupled receptor.

The metabotropic glutamate receptors (mGluRs) belong to family C of the G-protein-coupled receptor (GPCR) superfamily. The receptors are characterized by having unusually long amino-terminal domains (ATDs), to which agonist binding has been shown to take place. Previously, we have constructed a molecular model of the ATD of mGluR1 based on a weak amino acid sequence similarity with a bacterial periplasmic binding protein. The ATD consists of two globular lobes, which are speculated to contract from an "open" to a "closed" conformation following agonist binding. In the present study, we have created a Zn(2+) binding site in mGluR1b by mutating the residue Lys(260) to a histidine. Zinc acts as a noncompetitive antagonist of agonist-induced IP accumulation on the K260H mutant with an IC(50) value of 2 microm. Alanine mutations of three potential "zinc coligands" in proximity to the introduced histidine in K260H knock out the ability of Zn(2+) to antagonize the agonist-induced response. Zn(2+) binding to K260H does not appear to affect the dimerization of the receptor. Instead, we propose that binding of zinc has introduced a structural constraint in the ATD lobe, preventing the formation of a "closed" conformation, and thus stabilizing a more or less inactive "open" form of the ATD. This study presents the first metal ion site constructed in a family C GPCR. Furthermore, it is the first time a metal ion site has been created in a region outside of the seven transmembrane regions of a GPCR and the loops connecting these. The findings offer valuable insight into the mechanism of ATD closure and family C receptor activation. Furthermore, the findings demonstrate that ATD regions other than those participating in agonist binding could be potential targets for new generations of ligands for this family of receptors.

Percutaneous endovascular repair of infrarenal abdominal aortic aneurysms: a feasibility study.

BACKGROUND: Endovascular grafting has markedly reduced the invasiveness of the treatment of abdominal aortic aneurysms. By using a modification of technique for available closure devices, we have been able to achieve percutaneous repair of aneurysms. This study reviewed our initial experience with this technique. METHODS: Demographics and background data from patients undergoing endovascular repair of abdominal aortic aneurysms were reviewed from prospectively collected registry data. Operative notes and angiographic and computed tomography scan data were retrospectively reviewed to assess the success of the percutaneous approach. RESULTS: Fourteen patients have undergone percutaneous placement of the AneuRx (Medtronic, Sunnyvale, Calif) endovascular graft, with a modification of the technique for the Prostar (Perclose, Redwood City, Calif) device for access site closure. Main graft body introduction with a 22F sheath proved successful in nine of 12 (75%) deployments. Contralateral limb deployment through a 16F sheath was successful in 10 of 14 deployments (71.4%). Reasons for conversion to open groin incisions include inadequate percutaneous hemostasis (six cases), iliofemoral dissection (four cases), device failure (one case), and compromised distal flow (one case). Percutaneous deployment success appears to be improved with larger iliac artery dimensions, decreased calcification, and limited tortuosity, because of the limitation of complications related to delivering a larger diameter sheath. Of the 13 percutaneous endograft insertions that were attempted, six (46.2%) were completely successful. CONCLUSION: Percutaneous deployment of available devices is technically feasible by using modifications of technique with percutaneous closure devices, despite large introducer sizes. Further experience with this technique offers the potential for identifying patients in whom this will prove successful and for even further reducing hospital stay and recovery times for aneurysm repair.

Dacron carotid patch infection: a report of eight cases.

From 1995 through 1998, we encountered eight patients with infected Dacron patches after previous carotid endarterectomy. Two of the original operations had been done elsewhere, but the six patients who were collected from our own series represented 0.5% of the 1258 carotid endarterectomies we performed and 1.8% of the 340 synthetic carotid patches we applied without any comparable infections among another 918 patients who received either vein patch angioplasty (n = 843) or primary arteriotomy closure (n = 74) during the same 4-year study period. With a single exception ("no growth"), bacterial cultures that were obtained at the time of the eight reoperations revealed Staphylococcus (n = 4) or Streptococcus (n = 3) species. All of the infected Dacron patches were removed and were replaced with saphenous vein patches (n = 5) or interposition grafts (n = 3), after which appropriate oral (n = 2) or intravenous (n = 6) antibiotics were administered for 2 to 6 weeks. No postoperative deaths occurred, but there were 2 temporary cranial nerve injuries, 1 myocardial infarction, and 1 stroke that was related to preoperative angiography. A recurrent carotid infection has not developed in any of the eight patients during a mean follow-up interval of 16 months (range, 3-36 months).

An evaluation of the costs to health care institutions of endovascular aortic aneurysm repair.

BACKGROUND: Endovascular graft techniques hold great potential as a less invasive means for the repair of aortic aneurysms, yet the impact of these new modalities remains poorly elucidated. METHODS: Over a 10-month period at a single institution, 139 patients underwent infrarenal aortic aneurysm repair through a traditional open surgical technique (OS group, 94 patients) or an endovascular approach (ES group, 45 patients). Coated polyester prostheses (Hemashield; Boston Scientific Corporation, Boston, Mass) were used in the OS patients, whereas a modular nitinol polyester device (AneuRx; Medtronic, Sunnyvale, Calif) was used in the ES group. The hospital costs exclusive of professional charges were tabulated for the two groups using the hospital cost accounting system. Outliers were included in the data analysis. RESULTS: The mean operating room time was longer in the OS group than in the ES group (285 minutes vs 166 minutes). The average length of stay was also longer in the OS group (9.7 days vs 3.2 days). Hospital costs related to the length of stay were higher in the OS group, including laboratory costs ($327 higher), pharmacy costs ($688 higher), and nursing costs ($780 higher). Anesthesia costs were also higher in the OS group ($493 higher). Despite these marked differences, the total hospital cost averaged $7205 more in the ES group, a finding that was driven by the cost of the implantable devices themselves ($8976 in the ES group vs $597 in the OS group). CONCLUSIONS: Despite reductions in the length of hospitalization, the cost of care was substantially greater in patients undergoing endovascular aneurysm repair than in patients in whom an open surgical technique was used. These differences are driven by the cost of the endograft device itself, a cost that must not exceed $6000 if the economic impact of endovascular repair is to be in parity with traditional methods. Unless these economic disparities can be ameliorated, the economic impact of endovascular aneurysm repair may limit the widespread application of this technology.

Functional importance of the Ala(116)-Pro(136) region in the calcium-sensing receptor. Constitutive activity and inverse agonism in a family C G-protein-coupled receptor.

The calcium-sensing receptor (CaR) belongs to family C of the G-protein-coupled receptor superfamily. To date 14 activating mutations in CaR showing increased sensitivity to Ca(2+) have been identified in humans with autosomal dominant hypocalcemia. Four of these activating mutations are found in the Ala(116)-Pro(136) region of CaR, indicating that this part of the receptor is particularly sensitive to mutation-induced activation. This region was subjected to random saturation mutagenesis, and 219 mutant receptor clones were isolated and screened pharmacologically in a high throughput screening assay. Selected mutants were characterized further in an inositol phosphate assay. The vast majority of the mutants tested displayed an increased affinity for Ca(2+). Furthermore, 21 of the mutants showed increased basal activity in the absence of agonist. This constitutive activity was not diminished when the mutations were transferred to a chimeric receptor Ca/1a consisting of the amino-terminal domain of the CaR and the 7 transmembrane and intracellular domains of the metabotropic glutamate receptor mGluR1a. CPCCOEt, a noncompetitive antagonist acting at the 7 transmembrane domain of mGluR1a, suppressed the elevated basal response of the constitutively activated Ca/1a mutants demonstrating inverse agonist activity of CPCCOEt. Taken together, our results demonstrate that the Ala(116)-Pro(136) region is of key importance for the maintenance of the inactive conformation of CaR.

The role of Arg(78) in the metabotropic glutamate receptor mGlu(1) for agonist binding and selectivity.

The metabotropic glutamate receptors belong to family C of the G-protein coupled receptor superfamily. These receptors all possess large extracellular amino terminal domains, where agonist binding takes place. We have previously constructed a molecular model of the amino terminal domain of the mGlu(1) receptor based on a weak amino acid sequence similarity with a family of bacterial periplasmic binding proteins (PBPs). The residues Ser(165) and Thr(188) were demonstrated to be involved in agonist binding to the receptor. Here, we report that mutation of Arg(78) in the mGlu(1b) receptor to leucine or glutamate completely knocks out [3H]quisqualic acid binding to the receptor. The constructed mutants, R78L and R78E, have also been characterized in a inositol phosphate assay. Here, the potency of (S)-glutamic acid and (S)-quisqualic acid was reduced 1000- and 100-fold, respectively, on R78L compared to the wild type (WT) receptor. (S)-Quisqualic acid was as potent on mutant R78E as it was on R78L, whereas (S)-glutamic acid was unable to activate R78E significantly at concentrations up to 10 mM. In conclusion, Arg(78) appears to be essential for agonist binding to the mGlu(1) receptor, most likely, through the formation of an ionic bond between its positively charged side chain and the distal acid group of the agonists. Furthermore, the different impact of the two mutations on (S)-glutamic acid and (S)-quisqualic acid potencies strongly indicates that while Arg(78) appears to be a common site of interaction for the agonists, the Group I subtype selectivity of (S)-quisqualic acid is probably determined by other residues in the amino terminal domain.

Surgical repair of aneurysms involving the suprarenal, visceral, and lower thoracic aortic segments: early results and late outcome.

OBJECTIVE: The purpose of this study is to review our experience with surgical repair of lower thoracoabdominal and suprarenal aortic aneurysms to determine early and late survival rates and identify factors influencing morbidity and survival among these patients. MATERIALS: From 1989 through 1998, 165 consecutive patients underwent repair of 108 thoracoabdominal (55 group III and 53 group IV) and 57 suprarenal aneurysms. The study group consisted of 109 men and 56 women with a mean age of 70 years (median, 70 years; range, 29-89 years). Mean aneurysm diameter was 6.9 cm (median, 6.5 cm; range, 4-12 cm). There were 125 aneurysms (76%) repaired electively; 40 repairs (24%) were nonelective. The cause of 12 aneurysms (7%) was chronic aortic dissection; the remaining 153 (93%) were degenerative aneurysms. RESULTS: The early postoperative (30-day) mortality rates were 7% (9/125) for elective and 23% (9/40) for nonelective operations (P =.016). For both elective and urgent procedures, early mortality was 1.8% (1/57) for suprarenal aneurysm repair, 11% (6/53) for group IV thoracoabdominal aneurysms, and 20% (11/55) for group III thoracoabdominal aneurysms (P =.013, suprarenal vs group III). Spinal cord ischemia occurred after 6% (10/165) of aneurysm repairs (4% paraplegia, 2% paraparesis). None of the 57 suprarenal aneurysm repairs were complicated by spinal cord ischemia, whereas it occurred in 2% (1/53) of group IV thoracoabdominal aneurysms and 16% (9/55) of group III thoracoabdominal aneurysms (P =.001, suprarenal vs group III; P =. 016, group IV vs group III). Three (25%) of the 12 patients with dissection developed spinal cord ischemia; this compared with seven (5%) of 153 patients with degenerative aneurysms (P =.027). The cumulative 3-year survival rate for the entire series was 71% (95% CI, 64%-79%), and 5-year survival was 50% (95% CI, 40%-60%). CONCLUSIONS: Aneurysms involving the suprarenal, visceral, and lower thoracic aorta may be repaired with acceptable perioperative mortality and late survival rates. The risk of spinal cord ischemia is increased for patients with aortic dissection and may be stratified according to the proximal extent of the aneurysm.

The reduction of the allogenic transfusion requirement in aortic surgery with a hemoglobin-based solution.

OBJECTIVE: Because of allogenic red blood cell (RBC) availability and infection problems, novel alternatives, including hemoglobin-based oxygen-carrying solutions (HBOC), are being explored to minimize the perioperative requirement of RBC transfusions. This study evaluated HBOC-201, a room-temperature stable, polymerized, bovine-HBOC, as a substitute for allogenic RBC transfusion in patients undergoing elective infrarenal aortic operations. METHODS: In a single blind, multicenter trial, 72 patients were prospectively randomized two-to-one to HBOC (n = 48) or allogenic RBC (n = 24) at the time of the first transfusion decision, either during or after elective infrarenal aortic reconstruction. Patients randomized to the HBOC group received 60 g of HBOC for the initial transfusion and had the option to receive three more doses (30 g each) within 96 hours. In this group, any further blood requirement was met with allogenic RBCs. Patients randomized to the allogenic RBC group received only standard RBC transfusions. The efficacy analysis was a means of assessing the ability of HBOC to eliminate the requirement for any allogenic RBC transfusions from the time of randomization through 28 days. Safety was evaluated by means of standard clinical trial methods. RESULTS: The two treatment groups were comparable for all baseline characteristics. Although all patients in the allogenic RBC group required at least one allogenic RBC transfusion, 13 of 48 patients (27%; 95% CI, 15% to 42%) in the HBOC group did not require any allogenic RBC transfusions. The only significant changes documented were a 15% increase in mean arterial pressure and a three-fold peak increase in serum urea nitrogen concentration after HBOC. The complications were similar in both groups, with no allergic reactions. There were two perioperative deaths (8%) in the allogenic RBC group and three perioperative deaths (6%) in the HBOC group (P = 1.0). CONCLUSION: HBOC significantly eliminated the need for any allogenic RBC transfusion in 27% of patients undergoing infrarenal aortic reconstruction, but did not reduce the median allogenic RBC requirement. HBOC transfusion was well tolerated and did not influence morbidity or mortality rates.

Perioperative risk and late outcome of nonelective carotid endarterectomy.

PURPOSE: In an earlier report of our database for 1924 isolated carotid endarterectomies (CEAs) from 1989 to 1995, multivariable analysis results indicated that the urgency of operation unfavorably influenced the combined stroke and mortality rate (CSM). This study was conducted in an attempt to document the features that contribute to perioperative complications and late outcome in 314 patients for whom CEA was considered to be nonelective because of the severity of previous symptoms, carotid stenosis, or medical comorbidities. METHODS: All the hospital charts and outpatient records were reviewed retrospectively for the 209 men and 105 women who had undergone nonelective CEAs (median age, 69 years). Information regarding the clinical risk factors, the operative indications (CHAT classification), the severity and distribution of carotid disease, and the surgical management were analyzed to assess the impact on the 30-day CSM and on the long-term survival rate and neurologic events during a median follow-up period of 34 months. RESULTS: Previous symptoms had occurred in 285 patients (91%) and included cortical transient ischemic attacks in 47%, amaurosis fugax in 20%, completed strokes in 14%, unstable strokes in 2%, and nonspecific or miscellaneous symptoms in 8%. Preoperative angiography was performed in 308 patients (98%), which confirmed the presence of 80% to 99% ipsilateral carotid stenosis in 79% of the patients and >90% stenosis in 43%. The median interval between presentation and surgical treatment was 2 days, but 48% of the 314 CEAs were performed within 24 hours of presentation. The 30-day CSM was 6.7% and ranged from 3.4% for 29 patients with severe asymptomatic carotid stenosis to 14% for those patients with unstable strokes. The cardiac and pulmonary risk factors were the only variables that were related statistically to the CSM. During the follow-up period, the risk for ipsilateral stroke was significantly higher in women (risk ratio [RR], 2.38; 95% confidence interval [CI], 1.02 to 5.56; P =.04) and in patients with higher gradients of cardiac and pulmonary risk factors (RR, 2.8; 95% CI, 1.6 to 4.8 per gradient increase; P <.001). The risk was significantly lower in patients who had undergone vein patch angioplasty (RR, 0.29; 95% CI, 0.12 to 0. 71; P =.006) in comparison with synthetic patching. However, 38 of the 55 patients (69%) who underwent synthetic patching also had widespread atherosclerosis for which the saphenous veins already had been harvested for coronary bypass grafting surgery or infrainguinal revascularization. CONCLUSION: In our experience, the perioperative risk of nonelective CEA primarily is determined by incidental cardiopulmonary disease. Vein patch angioplasty appears to enhance late results, but the late stroke rate associated with synthetic patching also may have been influenced by the extent of vascular disease in our study group.

Elective surgical treatment of symptomatic chronic mesenteric occlusive disease: early results and late outcomes.

PURPOSE: The purpose of this study was to determine the safety and efficacy of the elective surgical treatment of symptomatic chronic mesenteric occlusive disease (SCMOD) and to identify the factors that influence the results of this procedure. METHODS: From 1977 to 1997, 85 patients (mean age, 62 years) underwent elective surgical treatment of SCMOD. The presenting symptoms were abdominal pain in 78 patients (92%) and weight loss in 74 patients (87%). The surgical procedures included retrograde bypass grafting in 34 patients (40%), antegrade bypass grafting in 24 patients (28%), transaortic endarterectomy in 19 patients (22%), local arterial endarterectomy with patch angioplasty in six patients (7%), thrombectomy alone in one patient (1%), and superior mesenteric artery reimplantation in one patient (1%). Thirty-five patients (41%) underwent concomitant aortic replacement. All the involved mesenteric vessels were revascularized in 21 patients (25%), whereas revascularization was incomplete for the remaining 64 patients (75%). Late information was available for all 85 patients at a mean interval of 4.8 years. RESULTS: There were seven early (<35 days) postoperative deaths (8%). The cumulative 5-year survival rate was 64% (95% confidence interval [CI], 53% to 75%), and the 3-year symptom-free survival rate was 81% (95% CI, 72% to 90%). Serious complications occurred in 28 patients (33%). The results of univariate analysis identified advancing age at operation (P <.001), cardiac disease (P =.03), hypertension (P =.03), and additional occlusive disease (P =.05) as variables associated with mortality. Concomitant aortic replacement (P =.037), renal disease (P =.011), advancing age ( P =.035), and complete revascularization ( P =.032) were associated with postoperative morbidity including mortality. Late recurrent mesenteric occlusive disease was seen in 21 patients (16 symptomatic and five asymptomatic). Nine patients (43%) died, and 8 patients (38%) required subsequent surgical or endovascular procedures to treat their recurrent lesions. The 3-year survival rate from recurrent mesenteric occlusive disease was 76% (95% CI, 66% to 86%). CONCLUSION: We conclude that the elective surgical treatment of SCMOD may be performed with reasonable early and late mortality rates and that most of the patients remain free from recurrent symptoms of mesenteric ischemia. Advancing age, cardiac disease, hypertension, and additional occlusive disease significantly influenced the overall mortality rates, and concomitant aortic replacement, renal disease, and complete revascularization were significantly associated with postoperative morbidity rates. Surveillance and appropriate correction of recurrent disease appear to be necessary for optimal long-term results.

Management of isolated common iliac artery aneurysms.

PURPOSE: Since isolated common iliac artery aneurysms are rare and there is no consensus regarding some aspects of their management, we reviewed our recorded experience with common iliac artery aneurysms from 1977 through 1993. METHODS: We were able to identify 25 patients having a total of 33 common iliac artery aneurysms on the basis of information maintained by our medical records staff, old surgical logs and a departmental registry that was implemented in 1989. Follow-up data were collected from outpatient charts and by telephone contact. New imaging studies were obtained for 14 patients who either underwent common iliac artery aneurysm repair without aortic replacement (aortic ultrasound scans, n = 7) or had no surgical treatment whatsoever (computerized tomography of the abdomen and pelvis, n = 7). RESULTS: All 25 patients were men (mean age, 71 years). Eighteen patients (72%) had elective (n = 14) or urgent (n = 4) operations to repair common iliac artery aneurysms with mean diameters of 3.8 cm and 5.8 cm, respectively. There was one postoperative death (5.5%) in conjunction with complementary renal revascularization in a patient with pre-operative renal insufficiency. During a mean follow-up period of 50 months, two (29%) of the seven patients who had not received bifurcation grafts at the time of their common iliac artery aneurysm procedures had developed infrarenal aortic aneurysms. Seven (28%) of the original 25 patients were observed without intervention for common iliac artery aneurysms measuring 2-2.5 cm in diameter. No common iliac artery aneurysm enlargement or new aortic aneurysms have been documented in any of these patients at a mean follow-up interval of 57 months. CONCLUSIONS: In our limited experience, the risk for spontaneous rupture appears to be concentrated among common iliac artery aneurysms exceeding 5 cm in diameter, while those that are less than 3 cm in diameter may fail even to enlarge under observation. Therefore, common iliac artery aneurysms measuring > or = 3 cm in size probably warrant surgical treatment, at which time simultaneous aortic replacement also should be a serious consideration.

Carotid endarterectomy in octogenarians: early results and late outcome.

PURPOSE: This study was undertaken to determine the safety and efficacy of carotid endarterectomy (CEA) in the octogenarian population at the Cleveland Clinic. METHODS: From 1989 to 1995, 182 CEAs were performed among 167 octogenarians (98 men, 69 women) with a mean age of 83 years (median, 83 years; range, 80 to 93 years). One hundred procedures (55%) were performed for severe asymptomatic stenosis, whereas 48 (26%) were performed for hemispheric transient ischemic attacks (TIAs) or amaurosis fugax, 24 (13%) for prior stroke, and 10 (5%) for vertebrobasilar symptoms. Thirteen CEAs (7%) were combined with myocardial revascularization, and another five (3%) represented carotid reoperations. Nine arteriotomies (5%) were closed primarily, whereas the remaining 173 (95%) were repaired using either vein patch angioplasty (141, 77%) or synthetic patches (32, 18%). Two patients were lost to follow-up, but late information was available for 165 patients (180 operations) at a mean interval of 2.7 years (median, 2.4 years; maximum, 7.4 years). RESULTS: Considering all 182 procedures, there were five early (<30 days) postoperative neurologic events (2.7%), including three strokes (1.6%) and two TIAs (1.1%). An additional 15 neurologic events occurred during the late follow-up period, consisting of 11 strokes (6.1%) and four TIAs (2.2%). The Kaplan-Meier estimated 5-year rate of freedom from stroke was 85% (95% confidence interval [CI], 77% to 93%). There was one early postoperative death (0.6%) of cardiac complications 9 days after CEA. The estimated 5-year survival rate was 45% (95% CI, 33% to 57%), and the 5-year stroke-free survival rate was 42% (95% CI, 30% to 53%). Multivariable analysis yielded age at operation (p = 0.001), abnormal creatinine level (p = 0.025), and chronic obstructive pulmonary disease (p = 0.019) as variables that significantly influenced the survival rate. The presence of chronic obstructive pulmonary disease (p = 0.009) and, surprisingly, a lesser degree of contralateral internal carotid stenosis (p = 0.003) were found to be significantly associated with stroke after CEA. Causes of late death were cardiovascular in 16 patients (30%), unknown in 13 (24%), carcinoma in six (11%), stroke in six (11%), and miscellaneous in 13 (24%). CONCLUSIONS: We conclude that CEA may be safely performed in selected octogenarians with carotid stenosis, and that the majority of these patients live the rest of their lives free from stroke. Therefore, age alone should not exclude otherwise-qualified candidates from consideration for CEA.

Cloning and characterization of a novel class I cytokine receptor.

The human gp130 cDNA sequence was used as a query to search an expressed sequence tag database (dbEST) to identify cDNA sequences with similarity to the cytokine class I receptor family. A novel class I cytokine receptor was identified in a human infant brain cDNA library and was named WSX-1. Full-length cDNA sequences for human and murine WSX-1 were isolated and characterized. The WSX-1 cDNA encodes a 636 amino acid transmembrane protein with an extracellular domain of 482 amino acids and a cytoplasmic domain of 96 amino acids. The structure of the WSX-1 protein most closely resembles that of gp130. Northern blot analysis indicates high levels of expression in thymus, spleen, lymph node, and peripheral blood leukocytes, suggesting a role for WSX-1 in modulation of the immune response.

Epidural versus general anesthesia: does anesthetic management influence early infrainguinal graft thrombosis?

A few contemporary reports have suggested that the use of epidural anesthesia may favorably influence early graft patency in patients undergoing infrainguinal revascularization. In order to test this hypothesis, we have retrospectively reviewed our experience with 303 primary femoropopliteal-tibial bypass procedures in 294 patients from January 1989 through June 1994. A total of 145 of these operations were done under epidural anesthesia (EA) and 158 under general anesthesia (GA); the demographic profiles for the patients in both of these groups were nearly identical. Thirteen patients (4.2%) died during the perioperative period (EA 3.4%, GA 5.0%; p = 0.48). Early graft thrombosis occurred in 35 patients (12%) during the same hospital admission (EA 14%, GA 9.4%; p = 0.28). There were no significant differences in the graft thrombosis rates for EA and GA with respect to surgical indications (claudication versus limb salvage), graft materials (vein versus synthetic), or the extent of revascularization (popliteal versus crural). Most graft failures appeared to be related to such conventional factors as disadvantaged outflow vessels and/or specific technical complications. Therefore, we conclude that the choice between EA and GA should continue to be made selectively on the basis of traditional anesthetic considerations.

Early outcome assessment for 2228 consecutive carotid endarterectomy procedures: the Cleveland Clinic experience from 1989 to 1995.

PURPOSE: Several randomized trials now have established guidelines regarding patient selection for carotid endarterectomy (CEA) that have been widely accepted but have little relevance unless they are considered in the context of perioperative risk. The purpose of this study was to demonstrate the feasibility of early outcome assessment using a computerized database. METHODS: Since 1989 demographic information and in-hospital results for all surgical procedures performed by the members of our department have been entered into a prospective registry. For the purpose of this report, we have analyzed the stroke and mortality rates for 2228 consecutive CEAs (2046 patients), including 1924 that were performed as isolated operations and 304 that were combined with simultaneous coronary artery bypass grafting (CABG). This series incidentally contains a total of 153 reoperations for recurrent carotid stenosis. RESULTS: The respective stroke and mortality rates were 0.5% and 1.8% for all isolated CEAs, 4.3% and 5.3% for all CEA-CABG procedures, and 4.6% and 2.0% for carotid reoperations. According to a multivariable statistical model, the composite stroke and mortality rate for isolated CEA was significantly influenced by female gender (p = 0.050), by the urgency of intervention (p = 0.026), and by carotid reoperations (p = 0.024). Gender (p = 0.030) and urgency (p = 0.040) also were associated with differences in the stroke rate alone; furthermore, the incidence of perioperative stroke was higher in conjunction with synthetic patching (odds ratio, 2.6; 95% confidence interval, 1.2 to 5.3) and was marginally higher with primary arteriotomy closure (odds ratio, 2.7; 95% confidence interval, 0.8 to 9.5) compared with vein patch angioplasty (1.3%). The method used to repair the arteriotomy was the only independent factor that qualified for the multivariable composite stroke and mortality models that were applied to the combined CEA-CABG procedures, but too few patients in this cohort had synthetic patches or primary closure to validate the perceived superiority of vein patching. CONCLUSIONS: Prospective outcome assessment is essential to reconcile the indications for CEA with its actual results, and it may lead incidentally to important observations concerning patient care.