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.

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.

A new injection portal for brachially inserted central venous catheter. A multicenter study.

Totally implantable portal systems are widely used for long-term central venous access. A new venous portal system inserted via the brachial veins (P.A.S. Port system, Pharmacia Deltec Inc, U.S.A.) was studied in five centres. From January 1988 through May 1989 61 systems were implanted. Fifty-two patients had malignant diseases. Nine cases had non-malignant disorders. The portals were implanted subcutaneously in the fore-arm and catheterization was done percutaneously (46) or by cutdown-technique (15) under local anesthesia. Catheter tip position was controlled by fluoroscopy or x-ray. The basilic vein (49) and the cephalic vein (12) were used. The total follow-up time for all systems was 323 months. Forty-five systems were still in use at the end of the observation period, six were explanted electively at the end of infusion therapy and six systems were still functioning at the time of the patient's death (at a maximum of 14 months after implantation). Temporary armphlebitis was noticed on the first postoperative week in five patients. Two P.A.S. Port systems were explanted due to infection and one because of skin rupture at the wound. One intact system was removed as it was thought to be leaking because of needle displacement. The P.A.S. Port system is easy and safe to implant with a high success rate and a low complication rate. It is well accepted by patients and nurses. The device should be advantageous in patients unsuitable for standard venous portal systems and offers an excellent alternative system for venous access.

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.

Surgery in long-term dialysis patients. Experience with more than 300 cases.

Three hundred twelve surgical procedures in patients with chronic renal failure have been characterized. There is a high incidence of operation in this expanding population. Multiple procedures for each patient were found in our 10 year study. Operative mortality was 1 percent and late mortality was about 10 percent per year. The survival curve predicted an 81 percent 2 year rate and a 60 percent 5 year survival rate. The high late mortality was likely related to the underlying disease process and the high proportion of complicating associated illnesses. The gross complication rate was high (64 percent), with the most frequent one being hyperkalemia. Other frequent complications were hemodynamic instability, infections, and fluid overload. A pattern of postoperative time to onset for the various complications was identified. Perioperative management requires aggressive, but appropriate metabolic, hematologic, and pharmaceutical intervention.

Management of Hickman catheter sepsis.

Hickman catheters have been shown to be efficacious and durable. We believe their performance can be safely prolonged with aggressive management of complications. One hundred sixty-five consecutive patients with catheters were followed prospectively and 28 episodes of sepsis in 24 patients were evaluated. At least 90 percent of septic catheters were salvaged with a combination of antibiotics and thrombolytic agents. When our protocol was followed, all episodes of sepsis were successfully treated. This included gram-positive and gram-negative organisms as well as one case of fungal sepsis. Since treatment can be handled mostly on an outpatient basis, there are benefits in regard to patient comfort as well as health care costs.

Abdominal wall hernias as a complication of peritoneal dialysis.

Home peritoneal dialysis has recently become an important addition to the therapy of chronic renal failure. Abdominal wall hernias have become more apparent as complications of this mode of dialysis, with isolated instances of incarcerations and one fatality. Results of our review of 276 patients receiving peritoneal dialysis revealed seven with hernias, an incidence of 2.5 per cent. Six patients with hernias were receiving c.a.p.d.; one patient was receiving c.c.p.d., and none was receiving i.p.d., for incidences of 17, 5 and zero per cent, respectively. All hernias found at presentation occurred within two to 20 months after peritoneal catheter placement. Most were ventral or umbilical, and all were repaired electively without serious complications. All patients with hernias had associated problems with leaks, peritonitis or predialysis hernias. In two of four patients with predialysis hernias, herniorrhaphy without catheter removal resulted in two recurrences. Abdominal wall hernias are a more frequent complication of c.a.p.d. and c.c.p.d., modalities which require large volumes of peritoneal dialysate during ambulatory hours. Review of the literature reveals that wound tensile strength and healing are decreased in those patients having renal disease with uremia, anemia and malnutrition. However, these factors do not increase the over-all incidence of hernias. Patients should be screened for hernias, and hernias should be repaired prior to catheter placement. Hernias presenting during dialysis are best treated by herniorrhaphy and hemodialysis postoperatively or low volume peritoneal dialysis to optimize the metabolic state.

Surgical management of renal hyperparathyroidism in the dialysis patient.

Over 12 years, 49 patients with hyperparathyroidism secondary to chronic renal failure under treatment with hemodialysis were treated with total parathyroidectomy. A portion of one gland was implanted in the sternocleidomastoid muscle. The operative indications were elevation of parathormone, serum calcium, and phosphorus, levels, pruritus, bone pain, pathologic fractures, and myalgia. Special postoperative complications discussed are hyperkalemia, hemorrhage, and respiratory obstruction. There were no operative deaths. No postoperative tetany was seen. Total parathyroidectomy should be performed in chronic renal failure patients with persistent elevation of serum calcium and parathormone levels, and who have pain, fractures, or soft tissue calcification. All postoperative parathyroidectomy patients should be observed for possible hyperkalemia.