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Biomedical subjects

L E Ratner

Publications and source records attributed to L E Ratner.

At least 37 records · Page 2Linked to original sources
PubMed2000

Plasmapheresis and intravenous immune globulin provides effective rescue therapy for refractory humoral rejection and allows kidneys to be successfully transplanted into cross-match-positive recipients.

BACKGROUND: Hyperacute rejection (HAR) and acute humoral rejection (AHR) remain recalcitrant conditions without effective treatments, and usually result in graft loss. Plasmapheresis (PP) has been shown to remove HLA- specific antibody (Ab) in many different clinical settings. Intravenous gamma globulin (IVIG) has been used to suppress alloantibody and modulate immune responses. Our hypothesis was that a combination of PP and IVIG could effectively and durably remove donor-specific, anti-HLA antibody (Ab), rescuing patients with established AHR and preemptively desensitizing recipients who had positive crossmatches with a potential live donor. METHODS: The study patients consisted of seven live donor kidney transplant recipients who experienced AHR and had donor-specific Ab (DSA) for one or more mismatched donor HLA antigens. The patients segregated into two groups: three patients were treated for established AHR (rescue group) and four cross-match-positive patients received therapy before transplantation (preemptive group). RESULTS: Using PP/IVIG we have successfully reversed established AHR in three patients. Four patients who were cross-match-positive (3 by flow cytometry and 1 by cytotoxic assay) and had DSA before treatment underwent successful renal transplantation utilizing their live donor. The overall mean creatinine for both treatment groups is 1.4+/-0.8 with a mean follow up of 58+/-40 weeks (range 17-116 weeks). CONCLUSIONS: In this study, we present seven patients for whom the combined therapies of PP/IVIG were successful in reversing AHR mediated by Ab specific for donor HLA antigens. Furthermore, this protocol shows promise for eliminating DSA preemptively among patients with low-titer positive antihuman globulin-enhanced, complement-dependent cytotoxicity (AHG-CDC) cross-matches, allowing the successful transplantation of these patients using a live donor without any cases of HAR.

Adult↗
PubMed2000

Laparoscopic live donor nephrectomy: the recipient.

BACKGROUND: Laparoscopic live donor nephrectomy offers advantages to the donor in terms of decreased pain and shorter recuperation. Heretofore no detailed analysis of the recipient of laparoscopically procured kidneys has been performed. The purpose of this study was to determine whether laparoscopic donor nephrectomy had any deleterious effect on the recipient. METHODS: A retrospective review was conducted of all live donor renal transplantations performed from January 1995 through April 1998. The control group received kidneys procured via a standard flank approach (Open). Rejection was diagnosed histologically. Creatinine clearance was calculated using the Cockroft-Gault formula. RESULTS: A total of 110 patients received kidneys from laparoscopic (Lap) and 48 from open donors. One-year recipient (100% vs. 97.0%) and graft (93.5% vs. 91.1%) survival rates were similar for the Open and Lap groups, respectively. A similar incidence of vascular thrombosis (3.4% vs. 2.1%, P=NS) and ureteral complications (9.1% vs. 6.3%, P=NS) were seen in the Lap and Open groups, respectively. The incidence of acute rejection for the first month was 30.1% for the Lap group and 31.9% for the Open group (P=NS). The rate of decline of serum creatinine level in the early posttransplantation period was initially greater in the Open group, but by postoperative day 4 no significant difference existed. No difference was observed in allograft function long-term. The median length of hospital stay was 7.0 days for both groups. CONCLUSIONS: Laparoscopic live donor nephrectomy does not adversely effect recipient outcome. The previously demonstrated benefits to the donor, and the increased willingness of individuals to undergo live kidney donation, coupled with the acceptable outcomes experienced by recipients of laparoscopically procured kidneys justifies the continued development and adoption of this operation.

Acute Disease↗
PubMed2000

Outcome in recipients of dual kidney transplants: an analysis of the dual registry patients.

BACKGROUND: A novel but controversial method to increase the utilization of aged donor kidneys is the transplantation of both kidneys as a dual transplant. Initial single-center reports demonstrated outcomes similar to single kidneys from younger donors. In this report, we compare outcome in recipients of kidneys from donors > or =54 years of age who received a single kidney transplant reported to the United Network for Organ Sharing Scientific Registry versus a dual kidney transplant reported to the Dual Kidney Registry. METHODS: A retrospective analysis was performed, comparing four donor and nine recipient and outcome variables between recipients of a single versus a dual transplant between March 1993 and March 1999. RESULTS: Dual versus single transplants from donors > or =54 years of age have a significantly decreased incidence of delayed graft function, and lower serum creatinines up to 2 years after transplant despite having kidneys from significantly older donors with poorer HLA matching. CONCLUSIONS: Dual kidney transplants improve graft performance and outcome in recipients of kidneys from donors > or =54 years of age.

Aged↗
PubMed2000

Laparoscopic nephrectomy for autotransplantation.

Proximal ureteral injuries often require extensive reconstruction to repair. Management options include nephrectomy, ileal ureter interposition, extensive spiral bladder flaps, or autotransplantation. We report a patient who sustained a proximal ureteral avulsion and underwent a less invasive repair by way of a laparoscopic nephrectomy and subsequent autotransplantation.

Adult↗
PubMed2000

Renal transplantation: laparoscopic live donor nephrectomy.

Laparoscopic nephrectomy is now performed at many centers worldwide. This technique for organ harvesting offers less postoperative pain, quicker convalescence, and an optimal cosmetic result when compared with the traditional open approach. With experience, the laparoscopic technique is accomplished without compromise to donor safety or allograft function, and complications are comparable with the rates in open historic series. Longer operative times and the need for disposable equipment result in greater hospital costs; however, the quicker convalescence permits patients to resume activity sooner, allowing marked cost savings for patients and employers. The laparoscopic technique is associated with a steep learning curve. Launching a successful laparoscopic living donor program requires a dedicated coordinated effort involving physicians, nurses, and hospital administration. The ultimate impact of this technique on the willingness of individuals to donate has not yet been determined.

Humans↗
PubMed2000

Shorter waiting times for hepatitis C virus seropositive recipients of cadaveric renal allografts from hepatitis C virus seropositive donors.

INTRODUCTION: The purposes of this study were: 1) to analyze the early results of cadaveric renal transplantation from either hepatitis C virus seropositive (HCV+ ) or hepatitis C virus seronegative (HCV-) donors into HCV + recipients; and 2) to determine whether HCV+ patients with end-stage renal disease (ESRD) might benefit from receiving renal allografts from HCV + donors. METHODS: From January 1997 to June 1999, 28 patients with ESRD and HCV infection underwent 29 cadaveric renal transplants. The data were reviewed retrospectively. Nineteen of the renal transplants were performed with allografts obtained from 15 HCV + donors and 10 with allografts obtained from 10 HCV- donors. The median follow-up was 16.2 months, with an average of 15.4+/-2 months. RESULTS: Recipients of HCV + renal allografts had shorter waiting times for transplantation. On average, patients who received a kidney from HCV + donors were transplanted 9+/-3 months after being placed on the transplant list, compared to 29+/-3 months for patients who received a kidney from a HCV- donor. Shorter waiting times were noted in every blood type group. There were no significant differences in rejection episodes, infectious complications, renal function, liver function, graft survival, or patient survival. CONCLUSIONS: The use of renal allografts from HCV + donors for HCV + recipients shortens the waiting time for these patients, with no short-term differences in renal and liver function, graft loss, or patient survival.

Adult↗
PubMed2000

Laparoscopic live donor nephrectomy: pre-operative assessment of technical difficulty.

Laparoscopic live donor nephrectomy decreases disincentives to live kidney donation. Thus, many centers are interested in adopting this procedure. However, the high stakes involved for both the donor and the recipient, and the technical difficulties of the operation, have tempered the enthusiasm of some surgeons. Ideally, if early in their series, surgeons could select patients that would be the least challenging technically, it would facilitate the dissemination of this operation. The purpose of this study is to determine if anatomic or radiologic parameters can accurately assess pre-operatively the degree of technical difficulty of laparoscopic live donor nephrectomy for any individual patient. Abdominal spiral three-dimensional CT scanning was performed prior to laparoscopic donor nephrectomy. CT scans were reviewed for six radiographic anatomic parameters. Seven clinical anatomic measurements relating to body habitus were recorded upon induction anesthesia at the time of surgery. Demographic data for gender, age, race, weight, height, and smoking history were collected. Following laparoscopic live donor nephrectomy, the following six component parts of the operation were graded on a scale of 1-4 (1 = easy, 4 = very difficult) for technical difficulty: a) mobilization of the colon; b) mobilization of the upper pole; c) dissection of the renal vein; d) dissection of the renal artery; e) division of the adrenal vein; and f) dissection of the ureter. Also, operative time, estimated blood loss, and intra-operative fluid requirements were recorded as surrogate markers of operative difficulty. Forty-one patients were included in the study. Laparoscopic donor nephrectomy was successfully completed in all cases. The sum of the difficulty scores was 9.9+/-3.1 (mean) (range, 6-18). No anatomic, demographic, or radiologic parameters were predictive of the total operative difficulty score. Of the surrogate markers, only operative time correlated with total difficulty score (R = 0.47, p = 0.003). Donor weight and abdominal girth correlated with operative time (R = 0.50, p = 0.002; R = 0.38, p = 0.019) but not with total difficulty score (R = 0.10, p = 0.51; R = -0.02, p = 0.90, respectively). When the easiest cases and the hardest cases (< or = 25th percentile and > or =75th percentile total difficulty score, respectively) were segregated out, again no anatomic, demographic, or radiologic parameters were predictive of operative technical difficulty. In conclusion, laparoscopic live donor nephrectomy technical difficulty could not be predicted by body habitus from the variables examined in this study. Hence, it was equally likely that performing laparoscopic live donor nephrectomy using a heavy donor would be technically easy, as using a thin donor would be difficult. Although, in general, operative time increased with donor size and weight, it appears that laparoscopic live donor nephrectomy operative technical difficulty is dependent upon such factors as amount of laparoscopic working space, quality of tissue planes, and retractability of the colon and mesocolon; factors that, to date, are not quantifiable.

Adult↗
PubMed2000

Expanded criteria donors: attempts to increase the renal transplant donor pool.

There is a growing disparity between the demand for and the supply of kidneys for transplantation. The demographics of the donor pool are also changing. The average potential cadaveric organ donor is now more likely to be older, at greater risk for co-morbid conditions such as hypertension or viral infections, and more likely to die from cerebrovascular disease. These factors have led to an expansion of the criteria that defines the suitable organ donor. Expanded criteria donors are defined as the following: (1) at the upper and lower extremes in age; (2) having a history of hypertension or diabetes; (3) hemodynamically unstable; (4) non-heartbeating (cardiopulmonary death rather than brain death); (5) seropositive for hepatitis B or C; (6) having systemic infections; (7) having displayed high-risk social behavior for HIV infection; (8) having a history of malignancy; (9) having abnormal organ function; or (10) with renal anatomic anomalies or injuries. Use of kidneys from these "expanded criteria donors" is a two-edged sword. While they provide more organs for transplantation, the risk of suboptimal recipient outcome is increased. A rational approach to the use of each of these types of kidneys and proper selection of recipients is essential to obtain acceptable results. The article reviews the factors that have contributed to the successful transplantation of kidneys procured from expanded criteria organ donors and how these organs can be allocated most efficaciously to the appropriate recipients.

Humans↗
PubMed2000

Laparoscopic live donor nephrectomy: outcomes equivalent to open surgery.

A shortage of kidney donors has contributed to the interest in laparoscopic live-donor nephrectomy. Three transperitoneal ports are used, as is an AESOP robot. To maintain urine flow, the donor is kept volume expanded during the procedure, and the pneumoperitoneum pressure is minimized. The most critical and hazardous part of the surgery is dissection of the renal artery and vein. Abundant periureteral tissue should be left to protect the blood supply. Harvest of the right kidney is more difficult. Placing the extraction incision in the right upper quadrant and using a Satinsky clamp instead of a stapling device at the origin of the renal vein will provide maximum venous length and help prevent postoperative thrombosis of the allograft. In the first 175 laparoscopic renal harvest procedures at Johns Hopkins, the complication rate was 14%, the rate of open conversion was 2%, and 3% of the patients required transfusions. These rates improved with experience. There was no significant difference in the performance of the allografts or the recovery of the recipients from what is seen after open kidney harvest. Wider acceptance of laparoscopic renal harvest will increase the number of donors and will be helped by development of methods and devices that shorten the learning curve.

Humans↗
PubMed1999

Laparoscopic live donor nephrectomy.

Live donor renal transplantation has many advantages including greater graft and patient survival, shorter waiting periods, improved human leukocyte antigen matching, and less cold ischemia. Until recently, disincentives from the operation, such as prolonged hospitalization, postoperative pain, and significant convalescence, have deterred live donor renal transplantation. This article describes the technique of laparoscopic live donor nephrectomy and briefly reports the results. The procedure has resulted in improved postoperative recovery and shorter convalescence, with no effect on recipient renal function.

Humans↗
PubMed1999

Chronic effect of pneumoperitoneum on renal histology.

BACKGROUND AND OBJECTIVE: Transient intraoperative oliguria is a constant phenomenon during laparoscopic procedures. Laboratory studies have demonstrated that this effect is secondary to a decrease in renal blood flow caused by the pneumoperitoneum. With the advent of laparoscopic harvest of the kidney for renal transplantation, a concern is that increased intra-abdominal pressure may compound the effect of acute cold and warm renal ischemia during transplantation. Acute transient renal ischemia can produce chronic sclerosing histopathologic changes in native kidneys which are similar to those seen in chronic allograft rejection. The effect of positive-pressure abdominal pneumoperitoneum (15 mm Hg) on native kidneys was examined using a rodent model. The effects on renal function and histologic features were also studied. MATERIALS AND METHODS: Twenty-four Harlan Wistar-Furth rats were divided into four groups: controls, 1-hour pneumoperitoneum-91-day survival, 5-hour pneumoperitoneum-91-day survival, and 5-hour pneumoperitoneum-7-day survival. Control animals underwent placement of the Veress needle and anesthesia but no induction of pneumoperitoneum. At the time of sacrifice, blood was sampled for serum creatinine measurement. Both kidneys were harvested for frozen and permanent section and stained using hematoxylin and eosin. Specimens were graded for inflammatory and ischemic/sclerotic changes in the interstitium, tubules, glomeruli, and vasculature by a renal pathologist using a histologic score (0-3). RESULTS: In all groups, at a sacrifice interval of either 1 week or 3 months, there were no statistical differences in the histologic score, serum creatinine concentration, or renal weight. CONCLUSIONS: In a rodent model, no signs of chronic ischemic histologic changes were detected for a period of 3 months after up to 5 hours of pneumoperitoneum. As well, there was no change in the serum creatinine concentration.

Animals↗