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.     

Long-term results of emergency coronary artery bypass grafting

Growth of the thermoacidophilic Gram-positive bacterium Alicyclobacillus acidocaldarius strain ATCC 27009 on maltose resulted in the increased production of a protein with apparent molecular mass of 40 kDa. By metabolic labelling with 14C-palmitic acid, the 40-kDa protein was identified as a lipoprotein. The protein exhibited maltose-binding activity at pH 3.5, as demonstrated by chromatography on cross-linked amylose. Partial amino acid sequence analysis revealed that the 40-kDa protein corresponds to the product of an open reading frame downstream from the amylase gene (amy) that displays similarity to enterobacterial maltose-binding proteins.     

Long-term results of mitral valve repair for myxomatous disease with and without chordal replacement with expanded polytetrafluoroethylene sutures

OBJECTIVE: This study was carried out to evaluate the long-term results of mitral valve repair for mitral regurgitation caused by myxomatous disease of the mitral valve and the late effects of chordal replacement with expanded polytetrafluoroethylene sutures in this operation. METHODS: A total of 324 patients with mitral regurgitation caused by myxomatous disease underwent mitral valve repair from 1981 to 1995; the group comprised 241 men and 83 women whose mean age was 58 +/- 14 years. Chordal replacement with expanded polytetrafluoroethylene sutures has been performed in 165 patients since 1985. Most of the patients who had chordal replacement with expanded polytetrafluoroethylene sutures had prolapse of the anterior leaflet or prolapse of both leaflets, whereas most patients who had mitral valve repair without chordal replacement had prolapse of the posterior leaflet. Patients were followed up at annual intervals and had a Doppler echocardiographic study. The follow-up was complete and extended from 6 to 156 months (mean 36 +/- 30 months). RESULTS: Two operative and 21 late deaths occurred (14 cardiac and 7 noncardiac). At 10 years the actuarial survival was 75% +/- 5%, the freedom from stroke was 94% +/- 2%, the freedom from transient ischemic attacks was 92% +/- 4%, the freedom from endocarditis was 99% +/- 1%, the freedom from mitral valve reoperation was 96% +/- 1%, and the freedom from severe mitral regurgitation was 93% +/- 3%. Chordal replacement with expanded polytetrafluoroethylene sutures had no effect on any of these end points. CONCLUSIONS: Mitral valve repair was feasible in most patients with mitral regurgitation caused by myxomatous disease and it was associated with low rates of valve-related complications. Chordal replacement with expanded polytetrafluoroethylene had no adverse effect on the late outcome and was believed to have increased the probability of mitral valve repair.     

Intestinal bypass surgery for morbid obesity. Long-term results

Since 1962, jejunoileal bypass has been performed on 59 male and 171 female subjects, aged 18 to 55 years; these patients were followed clinically. Postoperative weight loss at two years averaged 37% in men and 35% in women. Hypokalemia (23%), hypocalcemia (22%), hypoalbuminemia (9%), metabolic acidosis (14%), elevated liver enzyme values (41%), and hyperbilirubinemia (6%), were the most commonly encountered blood chemical alterations. Complications were arthritis syndrome (men, 8%; women, 19%). urinary calculi (men, 24%; women, 10%), cholelithiasis (men, 10%; women, 9%), liver impairment (men, 2%; women, 6%), and major emotional upset (men, 8%; women, 9%). Forty-nine percent of the men and 51% of the women required rehospitalization for management of complications, surgery for hernia, anorectal disorders, nutritional support, and metabolic study. There were 19 bypass-related deaths (8%), including 10 due to liver failure.     

Composite polytetrafluroethylene/vein bypass grafts: conventional distal vein segment or vein cuff?

Faecal samples from asymptomatic dairy cows and calves from a farm on the Island Falster, Denmark, were examined by a sucrose gradient flotation technique. Giardia cysts were found in 7.6% of the 92 samples, and estimated cyst excretion rates ranged from 50-200 cysts per gram faeces. Given that Giardia has the potential to cause clinical disease in cattle and to be transmitted to other animal species and humans, finding the parasite in cattle may be of major epidemiological significance. Future work should focus on elucidating the pathogenicity, transmission patterns and the genetic structure of Giardia populations in cattle in Denmark.     

Aortocoronary bypass grafting with expanded polytetrafluoroethylene: 12-year patency

The size of CAG repeats was compared in lymphocytes and skeletal muscle from nine patients with Huntington disease (HD) and two patients with Kennedy disease (KD). In HD, the number of CAG repeats did not differ between lymphocytes and skeletal muscle. In the two KD patients, however, the CAG expansion was larger in muscle than in lymphocytes. The difference in trinucleotide expansion between lymphocytes and muscle cells is not a universal phenomenon in trinucleotide repeat disorders, but seems to occur in disorders primarily affecting the neuromuscular system.     

Nonanastomotic pseudoaneurysm of expanded polytetrafluoroethylene axillofemoral bypass graft

A case of nonanastomotic pseudoaneurysm of a unilateral axillofemoral bypass graft is reported. The graft material used in this particular instance was an 8 mm, reinforced, thin-walled, fluorinated ethylene-propylene-ringed, expanded polytetrafluoroethylene (ePTFE). The pseudoaneurysm occurred 1 year after insertion of the graft and was not associated with any direct trauma. It manifested with a painful tender mass at the top of the body of the axillofemoral bypass graft at the level of the nipple line. There were no symptoms of localized or diffuse sepsis. Immediate surgical exploration confirmed the diagnosis of a pseudoaneurysm of the ePTFE graft. Successful repair of the disrupted segment was accomplished by use of an interposition, nonringed, reinforced, thin-walled, 8 mm ePTFE graft. To our knowledge this is the first case of a nonanastomotic pseudoaneurysm of a ringed, ePTFE, axillofemoral bypass graft not associated with direct trauma.     

Long-term results of arterial bypass surgery for impotence secondary to segmental vascular disease

PURPOSE: We evaluated the long-term results of arterial bypass surgery in impotent men carefully selected for nonatherosclerotic arterial vascular disease. MATERIALS AND METHODS: During a 7-year period only 11 of 1,352 impotent men (0.8%) were selected as ideal candidates for arterial vascular surgery. Initial evaluation included history, physical examination and a screening pharmacological erection test. Duplex ultrasonography was performed in patients who failed to respond adequately to pharmacological stimulation and were believed to be potential candidates for vascular surgery. Further evaluation included formal nocturnal sleep laboratory testing, dynamic infusion cavernosometry and arteriography. Dorsal artery bypass was performed in 9 patients and arterialization of the deep dorsal vein was done in 2. RESULTS: Average followup was 50 months (range 12 to 84). Initial followup duplex ultrasonography revealed a significant increase in cavernous artery peak systolic blood flow velocity (p < 0.001) and patent arterial anastomoses in all but 1 patient. The initial success rate without supplemental injection therapy was 82% and the final success rate was 64%. Even with long-term followup, 91% of the patients were improved from baseline, and were sexually active with (27%) or without (64%) injection therapy. CONCLUSIONS: Arterial bypass surgery can be successful in select impotent patients without generalized atherosclerosis or other risk factors for impotence. Further refinement of screening parameters may improve patient selection and long-term results of vascular surgery.     

Long-term Doppler echocardiographic results of aortic or mitral valve replacement with Biocor porcine bioprosthesis

OBJECTIVES: Our objectives were to evaluate the long-term bioprosthetic and cardiac functional outcome after insertion (over a 10-year period) of a new-generation porcine zero pressure-fixed Biocor bioprosthesis, as well as to determine the echocardiographic accuracy for selection of patients requiring reoperation. The long-term systematic Doppler echocardiographic assessment after valve replacement with this bioprosthesis is lacking. METHODS: Between January 1983 and January 1993, we inserted 756 Biocor prostheses in the aortic (619) or mitral (137) positions. All 51 patients who had a reoperation during the follow-up time were evaluated echocardiographically before reoperation. Additionally, 263 of 446 patients (59%) with aortic bioprostheses and 42 of 74 patients (57%) with mitral bioprostheses who were alive in January 1993 had long-term echocardiographic follow-up. RESULTS: Group A: Normally functioning bioprostheses were found in the aortic position in 242 of 263 patients and in the mitral position in 33 of 42 patients. Group B: Thirty patients had abnormal bioprosthetic function. Eleven patients had regurgitation, 3 had a combined lesion, and signs of calcification appeared in 16 patients with aortic valves, all with a peak gradient of above 60 mm Hg. Group C: Patients who had a reoperation (41 aortic and 10 mitral) within the follow-up period were followed up echocardiographically from the detection of a possible valve dysfunction until reoperation, and the findings accorded well with those at operation in 49 of 51 patients. CONCLUSIONS: These findings suggest that, during a long-term follow-up, most bioprostheses function normally, facilitating improved heart function. Abnormalities in a bioprosthesis usually develop gradually, enabling their detection by Doppler echocardiographic evaluations performed regularly or in case of any symptomatic deterioration.     

Clinical experience with expanded polytetrafluoroethylene (Gore-Tex) grafts for femoropopliteal arterial bypass

Thirty-seven grafts of expanded polytetrafluoroethylene were implanted in 28 patients in whom autogeneous saphenous vein was not available, either for symptoms of severe claudication or limb salvage. The length of follow-up ranges from 8 to 28 months . The patency rate is 86.9 percent for the patients with severe claudication and 71.4 percent in the limb salvage group; the overall patency rate is 81 percent. We believe that expanded polytetrafluoroethylene is a good prosthetic substitute when autogenous vein is unavailable.     

Long-term morbidity of jejunoileal bypass

A total of 169 patients who had jejunoileal bypass for morbid obesity were available for study more than 24 months after operation. Continuing high morbidity, especially "the bloats" and the regaining of weight, are arguments against the use of jejunoileal bypass unless clear medical indications exist.     

Selection of patients with critical limb ischaemia for femorodistal vein bypass

Striatal neurons from E15 rat embryos were dissociated, plated at low cell density on polyornithine or on astrocyte monolayers derived from the striatum (homotopic) or mesencephalon (heterotopic), and cultured in a chemically defined medium. After 2 to 10 days neurons could be divided in 3 classes according to their cell body diameter: small, medium or large. The percentage of small neurons which was very high 60% for GABAergic neurons on polyornithine after 2 days in vitro was reduced to 35% on mesencephalic astrocytes and to less than 20% on striatal astrocytes. The decrease in the number of small cells was paralleled by an increase in the number of multipolar medium size cells whereas the percentages of bipolar medium size and large neurons remained constant (55 and 4% respectively). All results obtained with the general neuronal population were replicated with the GABAergic sub-population which accounted for more than 50% of total neuronal population. These experiments confirm the beneficial influence of homotopic astrocytes on neuronal differentiation and on dendrite growth.     

Prospective randomized trial of carotid endarterectomy with primary closure and patch angioplasty with saphenous vein, jugular vein, and polytetrafluoroethylene: long-term follow-up

PURPOSE: This study examines the long-term clinical outcome and the incidence of recurrent stenosis (> or = 50%) after carotid endarterectomy (CEA) with primary closure (PC) versus vein patch closure (VPC), saphenous (SVP), and jugular vein (JVP) and polytetrafluoroethylene patch closure (PTFE-P). METHODS: A total of 399 CEAs were randomized into the following groups: 135 PC, 134 PTFE-P, and 130 VPC (SVP alternating with JVP). Postoperative duplex ultrasound scans were performed at 1, 6, and 12 months and every year thereafter. The mean follow-up was 30 months with a range of 1 to 62 months, and demographic characteristics were similar in all groups. Kaplan-Meier analysis was used to estimate the risk of restenosis and the stroke-free survival. RESULTS: The incidence of ipsilateral stroke was 5% (seven of 135) for PC, 1% (one of 134) for PTFE-P, and 0% for VPC (PC vs VPC, p = 0.008; PC vs PTFE-P, p = 0.034). Seven strokes occurred in the perioperative period. All three groups had similar mortality rates. The cumulative stroke-free survival rate at 48 months was 82% for PC, 84% for PTFE-P, and 88% for VPC (p < 0.01 for PC vs PTFE-P or VPC). PC had a higher incidence of recurrent stenosis and occlusion (34%) than PTFE-P (2%) and VPC (9%) (SVP 9%, JVP 8%) (p < 0.001). PTFE-P had a lower recurrent stenosis rate than VPC (p < 0.045). Restenoses necessitating a redo CEA were also higher for PC (11%) than for PTFE-P (1%) and VPC (2%) (p < 0.001). Women with PC had a higher recurrent stenosis rate than men (46% vs 23%, p = 0.008). Kaplan-Meier analysis showed that freedom from recurrent stenosis at 48 months was 47% for PC, 84% for VPC, and 96% for PTFE-P (p < 0.001). The SVP and JVP results were comparable. The mean operative diameter of the internal carotid artery was similar in patients with or without restenosis. Significantly more late internal carotid artery dilatations occurred in the VPC group compared with the PC group. CONCLUSIONS: Patch closure (VPC or PTFE-P) is less likely than PC to cause perioperative stroke. Patching was also superior in lowering the incidence of late recurrent stenoses, especially in women.     

Comparison of angioscopy and angiography for monitoring infrainguinal bypass vein grafts: results of a prospective randomized trial

PURPOSE: This study was designed to determine whether, in primary infrainguinal bypass grafts in which only saphenous vein is used as the graft conduit, routine monitoring with intraoperative angioscopy can improve early graft patency as compared with standard monitoring with intraoperative completion angiography; and to delineate the advantages and disadvantages of these two modalities and their respective roles for the routine monitoring of the infrainguinal bypass graft. METHODS: A total of 293 patients undergoing primary saphenous vein infrainguinal bypass grafting were prospectively randomized and monitored with either completion angioscopy or completion angiography. Clinical parameters, indications for operation, graft anatomy, and configuration were evenly matched in both groups. Forty-three bypasses were excluded from the study after randomization, including 12 veins randomized to angiogram, deemed inferior, and prepared with angioscopy. RESULTS: In the 250 bypass grafts (angioscopy 128, angiography 122) there were 39 interventions (conduit, 29; anastomosis, 8; distal artery, 2), 32 with angioscopy and 7 with angiography (p < 0.0001). Twelve (4.8%) of the 250 grafts failed in less than 30 days, four (3.1%) of 128 in the angioscopy group and eight (6.6%) of 122 in the angiography group (p = 0.11 by one-sided hypothesis test). CONCLUSION: Although no statistical improvement in the proportions of failures in primary saphenous vein bypass grafts routinely monitored with completion angioscopy rather than the standard completion angiogram was demonstrated, the study delineates a trend that favors completion angioscopy for routine vein graft monitoring and demonstrates the advantages of angioscopy in preparing the optimal vein conduit.     

A new porto-systemic bypass technique for hepatopancreatoduodenectomy with portal vein resection

When reconstructing the portal vein (PV) following hepatopancreatoduodenectomy (HPD) with PV resection, a new porto-systemic bypass (PSB) technique can be employed to prevent intestinal vascular congestion. The Whipple procedure is performed in a standard manner, as long a portion of the gastrocolic trunk is preserved for insertion of an antithrombogenic catheter (ATC). After harvesting the left external iliac vein and exposing the right great saphenous vein, the end of the ATC is inserted in the superior mesenteric vein via the gastrocolic trunk in the distal direction and the other end of the ATC is inserted in the greater saphenous vein. PSB is achieved as a result of the venous pressure gradient. By employing this technique, an ATC can be inserted without damaging another mesenteric venous branch and with minimal damage to the endothelium, and the small intestine is not exposed in the operative field until enteric reconstruction is started. This technique is a promising option for PSB during HPD with PV resection.     

The femoral artery-femoral vein polytetrafluoroethylene graft: a 14-year retrospective study

The purpose of this study was to determine the relationship between sarcoma tumor grade and the quantitative tumor metabolism value for [F-18]fluorodeoxyglucose (FDG) determined by positron emission tomography (PET) imaging. Seventy patients with bone or soft-tissue sarcomas underwent PET scanning with quantitative determination of tumor FDG metabolic rate (MRFDG) before treatment. MRFDG (micromol/g/min) for each tumor was compared with National Cancer Institute tumor grade, S-phase percentage, and percentage of aneuploidy of the tumor population. The pretreatment quantitative determination of tumor MRFDG by PET correlates strongly with tumor grade but not with the other selected histopathological tumor correlates. In addition, overlap of MRFDG PET values with tumor grade suggests that PET, an objective tumor measurement, may provide an alternative means of assessing tumor biological potential or may have the potential to overcome some of the limitations of traditional pathological evaluation. FDG PET can uniquely provide a metabolic profile of a diverse group of sarcomas noninvasively and provide clinically relevant tumor biological information.