Patency and flow characteristics using stapled vascular anastomoses in dialysis grafts.

BACKGROUND: Improving patency of hemodialysis grafts is challenging. Vascular stapling creates nonpenetrating anastomoses, possibly decreasing intimal hyperplasia. We investigated patency and flow characteristics of stapled hemodialysis grafts. METHODS: Eighty-six grafts (41 stapled, 45 sewn) were placed in 84 patients (prospective, randomized). The groups had comparable demographics. RESULTS: Thirty-six grafts were functioning at the study endpoint. Complications in both groups were similar. The primary patency (stapled, 342 days versus sewn, 382 days; P = 0.67) and secondary patency (stapled, 513 days versus sewn, 507 days; P = 0.76) had no significant differences. Flow characteristics were similar between the groups. Thrombectomies per patient-year were 1.01 for stapled grafts and 1.12 for sewn grafts (not significant). Stapling decreased the average operating time by 4.5 minutes. CONCLUSIONS: Stapled and sewn anastomoses have similar primary and secondary patency and flow characteristics, with minimal operative time differences. Stapled anastomoses are safe but had no advantage over sewn anastomoses in this study.

Cost-effective management of common bile duct stones: a decision analysis of the use of endoscopic retrograde cholangiopancreatography (ERCP), intraoperative cholangiography, and laparoscopic bile duct exploration.

BACKGROUND: There are a variety of approaches to the diagnosis and treatment of common bile duct (CBD) stones in patients undergoing laparoscopic cholecystectomy (LC). METHODS: Decision modeling was used to evaluate the cost-effectiveness of four strategies for managing CBD stones around the time of LC: (a) routine preoperative endoscopic retrograde cholangiopancreatography (ERCP) (preoperative ERCP), (b) LC with intraoperative cholangiography (IOC), followed by laparoscopic common bile duct exploration (LCDE), (c) LC with IOC, followed by ERCP (postoperative ERCP), and (d) expectant management (LC without any tests for CBD stones). Local hospital data were used to estimate costs. Cost-effectiveness was expressed in terms of the cost per case of residual CBD stones prevented (in excess of the cost of LC alone). Diagnostic test characteristics, procedure success rates, and adverse event probabilities were derived from a systematic review of the literature. Sensitivity analysis was used to explore the effect of uncertainty on the results of the model. RESULTS: LC alone was the least costly strategy, but it was also the least effective. Of the more aggressive strategies, LCDE and preoperative ERCP were associated with marginal costs of $5993.60 and $299,259.35, respectively, per case of residual CBD stones prevented. Postoperative ERCP was more costly and less effective than LCDE, but it had a lower cost-effectiveness ratio than preoperative ERCP when the prevalence of CBD stones was <80%. CONCLUSIONS: Compared to other common approaches, laparoscopic CBD exploration is a cost-effective method of managing CBD stones in patients who undergo LC. If expertise in LCDE is unavailable, selective postoperative ERCP is preferred over routine preoperative ERCP, unless the probability of CBD stones is very high (>80%).

Effect of an esophageal bougie on the incidence of dysphagia following nissen fundoplication: a prospective, blinded, randomized clinical trial.

HYPOTHESIS: Based on retrospective, uncontrolled studies, it has been claimed that Nissen fundoplication should be performed over an esophageal bougie to minimize postoperative dysphagia. We hypothesized that a surgeon experienced in laparoscopic fundoplication will have similar rates of postoperative dysphagia whether or not an esophageal bougie is used. DESIGN: A patient and observer blinded, randomized, prospective clinical trial to assess the effect of intraoperative bougie use. SETTING: A tertiary care teaching hospital that is a regional referral source for complex laparoscopic foregut surgical procedures. PATIENTS: Three hundred thirty-six consecutive patients referred for laparoscopic fundoplication between March 1, 1996, and July 31, 1998, were evaluated for eligibility based on inclusion criteria and, if applicable, were offered randomization for fundoplication with or without a 56F bougie. One hundred seventy-one patients were enrolled in this study. INTERVENTIONS: All patients underwent laparoscopic Nissen fundoplication, 81 with a bougie (hereafter referred to as the bougie group) and 90 without a bougie (hereafter referred to as the no bougie group). MAIN OUTCOME MEASURES: Dysphagia severity and frequency were assessed by a blinded observer using a standardized scoring system. Incidence of complications related to the use or absence of a bougie, operative times, and postsurgical recovery was also assessed. RESULTS: The mean operating time was 148 minutes (range, 65-295 minutes). The overall operative morbidity was 9% (7. 4% in the bougie group and 11% in the no bougie group, P=.41). One esophageal injury (1.2%) occurred in the bougie group. The 30-day mortality was 0. Long-term dysphagia assessment was completed in 90% of patients, with a mean follow-up of 11 months. Overall, long-term postoperative dysphagia was present in 13 patients (17%) in the bougie group and 24 patients(31%) in the no bougie group (P=.047). Severe dysphagia occurred in 5% of patients in the bougie group and 14% in the no bougie group. CONCLUSION: This study confirms the dogma that use of a large-caliber stent during the creation of a fundoplication decreases the long-term incidence of dysphagia; albeit at the risk of injury from the introduction of a bougie.

Single limb patency of polytetrafluoroethylene dialysis loop grafts maintained by traumatic fistulization.

The purpose of this report is to describe an unusual presentation of obstructive neointimal hyperplastic lesions in loop prosthetic dialysis grafts. The case histories and imaging studies of two patients with partial graft thrombosis are presented. The literature of unexpected fistulae from prosthetic dialysis grafts to adjacent veins is reviewed. Signs and symptoms that would lead a clinician to suspect the diagnosis are emphasized. There were two dialysis grafts with partial thrombosis and arterial limb patency maintained by iatrogenic fistula. These fistulae occurred from the erosion of pseudoaneurysms in one case and an apparent needle stick without pseudoaneurysm in the other. Both grafts had high-grade stenotic lesions affecting the venous outflow. In the first case this was not recognized until the graft reclotted 2 days after thrombectomy. In the most extreme cases of graft/vein fistulae, i.e., partial graft thrombosis with arterial limb patency maintained by the fistula there is always associated venous anastomotic or outflow stenoses which must be addressed.

Reinforced versus nonreinforced polytetrafluoroethylene grafts for hemodialysis access.

BACKGROUND: Two major types of polytetrafluoroethylene (PTFE) graft material have been available for the past 20 years. Previous studies have suggested that nonreinforced PTFE performs better as a hemodialysis conduit than reinforced PTFE. We have had experience with both materials for the past 20 years. METHODS: This is an outcome study that is based on concurrent and retrospective data. Patients were accrued into the study from 1987 to 1995. There were 632 grafts that were entered onto a data base and analyzed by a biostatistician. RESULTS: Nonreinforced PTFE performed better than reinforced PTFE in every category and subgroup. Both mean duration and life-table analysis of the primary patency were statistically significant (P < 0.05). The secondary patencies were similar, with 80% of the nonreinforced and 77% of the reinforced functioning at 1 year. The median duration for secondary patency of all grafts was 1,554 days. Diabetic patients comprised 50% of the patient population. CONCLUSION: Nonreinforced PTFE performs better than reinforced PTFE as a hemodialysis conduit. Until a multicentered prospective randomized study can be achieved, a preponderance of data suggests that nonreinforced PTFE should be the material of choice for hemodialysis access.

Local delivery of heparin with balloon angioplasty: results of a prospective randomized trial.

PURPOSE: To evaluate the effectiveness of local delivery of heparin via hydrogel-coated balloons in the treatment of vascular stenoses associated with hemodialysis access. MATERIALS AND METHODS: This was a randomized, prospective trial comparing treatment with hydrogel-coated balloon catheters delivered with heparin coating (n = 33) and without (n = 26). All patients were undergoing hemodialysis, and all stenoses involved the venous anastomosis of a dialysis graft or a native vein. The heparin-treated balloons were soaked in concentrated heparin and delivered in a protected manner to help prevent washout of heparin. RESULTS: The mean primary patencies were 143 days with heparin treatment and 214 days without heparin (P = .174). The mean assisted primary patencies were 165 days with heparin and 194 days without (P = .315). The mean secondary patencies were 351 days with heparin and 384 without (P = .81). CONCLUSION: In this population with this technique, the treatment outcome of venous outflow stenosis in patients with dialysis grafts is not improved with local delivery of heparin.

Percutaneous transluminal angioplasty versus endovascular stent placement in the treatment of venous stenoses in patients undergoing hemodialysis: intermediate results.

PURPOSE: This report describes intermediate findings from an ongoing prospective randomized trial comparing the results of percutaneous transluminal angioplasty (PTA) with results of endovascular stent placement in patients undergoing hemodialysis. PATIENTS AND METHODS: Among 87 consecutive patients with venous stenoses or occlusions, 47 (54%) were treated with PTA alone and 40 (46%) were treated with PTA and stent placement. RESULTS: For peripheral sites, the primary patency rates for PTA at 60, 180, and 360 days were 55%, 31%, and 10%, respectively, and for stents were 36%, 27%, and 11%, respectively (P = .6528). The secondary patency rates for PTA at 60, 180, and 360 days were 94%, 80%, and 71%, respectively, and for stents were 73%, 64%, and 64%, respectively (P = .1677). For central sites, the primary patency rates for PTA at 60, 180, and 360 days were 81%, 23%, and 12%, respectively, and for stents were 67%, 11%, and 11%, respectively (P = .4595). The secondary patency rates for PTA were 100% at each interval, and for stents were 100%, 89%, and 78%, respectively (P = .5408). CONCLUSION: Intermediate results suggest that, overall, there is no difference in the patency rates for peripheral venous stenoses in dialysis patients treated with PTA or PTA and endovascular stent placement. At this time, the numbers of patients are too small to conclude if certain sites such as larger central veins will respond better to one treatment or the other.

Does the use of erythropoietin in hemodialysis patients increase dialysis graft thrombosis rates?

Erythropoietin (EPO) is highly efficacious in the treatment of the anemia of chronic renal failure. Evidence for a reported serious side effect, increased dialysis graft thrombosis, is equivocal. Sixty-four hemodialysis patients utilizing polytetrafluoroethylene (PTFE) grafts were treated with EPO. The patients served as their own historical controls. There were 1.188 thrombectomies and 0.222 mechanical problems per 1,000 patient-days prior to the initiation of EPO treatment. With EPO, the values were 0.656 and 0.222, respectively. Patients were separated into low-, medium-, and high-dose EPO groups and analyzed within groups for the effect of EPO and between groups for a dose-dependent response. According to an analysis of variance procedure, there was no statistically significant differences between the groups, which suggests that EPO is not thrombogenic to dialysis grafts.

Venous stenoses in patients who undergo hemodialysis: treatment with self-expandable endovascular stents.

During a 32-month period, 25 modified self-expandable endovascular stents were placed in 20 hemodialysis access sites to treat 21 stenoses and four occlusions in 19 patients. All stenoses were initially dilated with a high-pressure balloon. The initial success rate was 90% (18 of 20 access sites). The stents were patent from 0 to 960 days (mean duration of follow-up, 309 days). At 2 years follow-up, the patency rates were as follows: primary, 25%; secondary, 34%; and tertiary, 42%. The morbidity rate associated with this procedure was 15% (three of 20 sites); the mortality rate, 5% (one of 19 patients). All five complications (graft or native-vein thrombosis [n = 2], nerve deficits [n = 2], and death secondary to sepsis [n = 1]) occurred in three patients early in the study, before the use of prophylactic antibiotics and refinements in technique. The best results occurred in patients in whom the stenosis or occlusion affected a large vein that had no acute angle and was away from venous confluences such as the femoral and iliac regions.

Long-term patency of polytetrafluoroethylene graft fistulas.

Polytetrafluoroethylene grafts have been the mainstay for hemoaccess at our dialysis unit since 1976. Of 528 grafts placed in the forearm, 81 were evaluated for long-term patency and complication rates. When appropriate diagnostic studies and clinical signs delineate the cause of graft problems, a variety of surgical techniques can be used to maintain graft patency. The overall patency rate was 81 percent at 4.47 years. There were 3.5 complications per graft and 1 procedure per 1.25 years of follow-up. Over two thirds of the grafts had minimal complications and showed a 95 percent patency rate at 4.76 years. Impra grafts seemed to fare better than Gore-tex grafts, but their patency and duration were similar. Polytetrafluoroethylene grafts are easy to use, easy to revise and repair, have a long shelf life, and can withstand repeated dialysis access for many years.

Repeat parathyroid operation associated with renal disease.

One hundred ten patients who had undergone operation for secondary and tertiary hyperparathyroidism have been described. Ninety patients had secondary disease and 20 patients had tertiary disease after renal transplantation. From these two groups, 18 patients had repeat operations for control of recurrent or persistent disease. The incidence of repeat operations was 14 percent. Causes were graft-dependent hyperparathyroidism, supernumerary glands in the neck or mediastinum, and incomplete identification of glands in the neck. The most important risk factor is continued long-term dialysis in functionally anephric patients. We recommend that patients with hyperparathyroidism associated with chronic renal failure undergo total parathyroidectomy with autotransplantation. If repeat operation is necessary, a reduction in glandular mass with autotransplantation is preferred. In selected patients, total parathyroidectomy can be considered because of the increased risk of aluminum bone disease.

Improving the outcome in gallstone ileus.

A 32 year retrospective review of 24 cases of gallstone ileus from the hospitals of Oregon Health Sciences University has been presented. Nineteen patients (79 percent) were female and 18 (75 percent) were more than 70 years of age. Fifty-four percent of the patients had a correct preoperative diagnosis that correlated well with the roentgenographic findings. Enterolithotomy was the most frequently employed operation, and cholecystoduodenal fistulas were positively identified in 61 percent of the patients. Most obstructions occurred in the distal ileum (48 percent). Wound infections occurred in six patients (26 percent), and there were three deaths for a mortality rate of 13 percent. Of note, the incidence of wound infections and mortality is found to be decreasing. This is related to the more frequent use of prophylactic antibiotics. The controversy regarding performing an enterolithotomy alone versus a one stage procedure has been reviewed and several interesting and atypical cases have been briefly discussed.

Delayed type hypersensitivity to gangliosides in the Lewis rat.

Systematic study of the immunologic properties of gangliosides has been hampered by the lack of a suitable assay. In this study, significant delayed type hypersensitivity reactions to gangliosides were observed in Lewis rats immunized with whole guinea pig spinal cord (GP-SC) in complete Freund's adjuvant (CFA). The reaction was manifested by an increase in ear thickness after intradermal injection of a mixture of gangliosides and methylated bovine serum albumin (mBSA). No responses were observed to either gangliosides or mBSA alone. The reaction to gangliosides increased after immunization, persisted for 48 h, and was characterized by perivascular infiltration of mononuclear cells. Further evidence for a cellular response was demonstrated by the transfer of ganglioside-specific ear swelling by cultured spleen cells. The response to gangliosides was not due to contamination with myelin basic protein (BP) since no reaction to gangliosides was observed in GP-BP/CFA-immunized rats, and no reaction to BP was observed in ganglioside/CFA-immunized rats. In BP-immunized rats, responsiveness to BP persisted after recovery from clinical EAE for at least 60 days. However, no response to gangliosides was observed in BP-immunized animals after recovery from clinical EAE, suggesting the lack of autosensitization to gangliosides due to the disease process itself.

Vascular endothelial cells in cell-mediated immunity: adoptive transfer with in vitro conditioned cells is genetically restricted at the endothelial cell barrier.

Delayed-type hypersensitivity (DTH) is a cell-mediated immune response that can be adoptively transferred in rats when greater than 2 X 10(8) cells from peritoneal exudate, lymph nodes, or spleen are used. We have shown that by using an in vitro conditioning step with antigen, transfer can be subsequently carried out with as few as 2 X 10(7) spleen cells. The magnitude of DTH was reflected in ear swelling after intradermal injection of antigen [tuberculin or keyhole limpet hemocyanin (KLH)] and confirmed histologically. The transfer was antigen specific, requiring the sensitizing antigen in both the in vitro conditioning step and in the ear test challenge. Adoptive transfer with conditioned cells was genetically restricted by alleles of the RT-1 region [major histocompatibility complex (MHC) of the rat]. Brown Norway strain (n haplotype) immune cells would not transfer DTH to Lewis (1 haplotype), ACI (a haplotype), or Buffalo (b haplotype) rats, whereas each strain would transfer DTH to syngeneic recipients. Moreover, this pattern of restriction held for all strains when tested in reciprocal fashion. In additional experiments, F1 to parental bone marrow chimeras were constructed so that bone-marrow-derived cells and non-bone-marrow-derived cells were of different RT-1 haplotypes. When these chimeras were used as recipients, transfer of DTH was only observed when immune donor cells and recipient non-bone-marrow-derived cells were syngeneic. These results point to the critical role of non-bone-marrow-derived cells (endothelial cells) in the DTH reaction.

The island cheek flap: repair of cervical esophageal stricture and new extended indications.

Seven patients had reconstruction with an island cheek flap based on the facial vein and artery. The flap carries a swatch of buccal mucosa that can be rotated inferiorly as far as the superior mediastinum and superiorly to the oral cavity. Five patients had repair of cervical esophageal strictures and fistulas. In four, results were very successful. One patient had diminished but persistent dysphagia which was shown to be secondary to a carcinomatous polyneuropathy; however, he had complete resolution of aspiration after correction of his mechanical obstruction and tracheoesophageal fistula. Morbidity was minimal. Parotiditis developed in one patient who had Stensen's duct ligated. Minor numbness of the lip and a single case of Frey's syndrome were also observed. In another patient, reconstruction of the floor of the mouth preserved normal speech and swallowing. Finally, a permanent speech fistula was also created but was substantially taken down because of functional dissatisfaction. Other potential applications need to be explored.

Outcome and sepsis after splenectomy in adults.

Of 277 splenectomies performed over 10 years, 24.2 percent were incidental. Operative mortality in this group was 14.9 percent, which is higher than that encountered after splenectomy for any other indication. A majority of the deaths were from septic causes, and infectious complications accounted for most of the morbidity as well. This finding is in marked contrast to the paucity of infectious morbidity and mortality in patients with all other splenectomies. Of the 251 patients who survived these operations, follow-up was available on 175. Twenty-six had received Pneumovax, and 4 of these patients died, none from infectious causes. There were 20 septic deaths among the 149 unvaccinated patients, including 3 cases of fulminant pneumococcal sepsis.