Calibration curves for biological dosimetry by fluorescence in situ hybridisation.

Dose-response curves were measured for the induction of chromosomal aberrations in peripheral blood lymphocytes after acute exposure in vitro to 60Co gamma rays. Blood was obtained from four different healthy donors, and chromosomes were either observed at metaphase, following colcemid accumulation, or prematurely condensed by calyculin A. Cells were analysed in three different Italian laboratories. Chromosomes 1, 2, and 4 were painted, and simple-type interchanges between painted and non-painted chromosomes were scored in cells exposed in the dose range 0.1-3.0 Gy. The chemical-induced premature chromosome condensation method was also used combined with chromosome painting (chromosome 4 only) to determine calibration curves for high dose exposures (up to 20 Gy X rays). Calibration curves described in this paper will be used in our laboratories for biological dosimetry by fluorescence in situ hybridisation.

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.

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.

Craniofacial biostereometrics.

We believe that biostereometrics can be useful to the craniofacial surgeon in providing a highly accurate, reproducible diagnostic and presurgical tool that is inexpensive and noninvasive. It can help visualize complex pathologic bony abnormalities, resolve ambiguous CT scans, and predict soft-tissue changes secondary to alterations in bony contours when used in conjunction with CT scans and cephalograms.

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.

PTFE graft arteriovenous fistulae for hemodialysis access.

The use of expanded PTFE graft arteriovenous fistulae for hemodialysis access is becoming increasingly popular. Its low infection rate, low thrombogenicity, low body reactivity, and longevity make it an ideal vascular substitute. From May 1976 to June 2, 1978 we have placed 102 grafts in 89 patients, many of whom represent management problems of other access means. Major complications are pseudointimal proliferation at the venous anastomosis, pseudoaneurysm formation, and thrombosis, usually associated with low blood volume. These problems are, however, readily rectifiable. Other types of grafts, according to the literature, have not been successful for hemodialysis access.

Angiosarcoma of the breast.

Two surviving patients treated for angiosarcoma of the breast are presented, along with a summary of the previous 44 reported cases. Because of early vascular metastasis and indistinct tumor margins, early excision with very wide margins, including total mastectomy, surrounding muscle and bone, is necessary.