Karl-Heinz Dietl

Preoperative diagnosis of bile duct strictures--comparison of intraductal ultrasonography with conventional endosonography.

Background: The accuracy of intraductal ultrasonography (IDUS) and endoscopic ultrasonography (EUS) were compared in diagnosing biliary obstruction and in predicting surgical resectability. Methods: Fifty-six patients with biliary obstruction were investigated preoperatively with both conventional EUS and IDUS. The ultrasonographic miniprobe was inserted into the bile duct system through the working channel of the duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). Conventional endosonography was performed with echoendoscopes in a standard technique. Images of endoluminal ultrasonography were prospectively reviewed and compared with intraoperative findings and resection specimen analyses. Results: IDUS exceeded EUS in terms of accuracy (IDUS, 89.1%; EUS, 75.6%; P < 0.002), sensitivity (IDUS, 91.1%; EUS, 75.7%; P < 0.002), specificity (IDUS, 80%; EUS, 75%; NS), and T-staging (IDUS, 77.7%; EUS, 54.1%; P < 0.001). In bile duct carcinomas the accuracy rate for lymph node staging using IDUS (60%) is comparable with that using EUS (62.5%). In pancreatic carcinomas, however, lymph node staging using IDUS (13.3%) is significantly (P < 0.002) inferior to EUS (69.2%). Endoluminal ultrasonography may predict the potential resectability of bile duct tumors (IDUS, 81.8%; EUS, 75.6%; P < 0.002). Conclusions: IDUS proved to be accurate in preoperative diagnosing and T-staging of malignant biliary strictures, whereas it is not suitable for lymph node staging. IDUS using miniprobes during ERCP exceeds conventional EUS in terms of depiction of bile duct obstruction, diagnostic accuracy, and sensitivity and in the prediction of surgical tumor resectability. Additionally, different to EUS, IDUS can conveniently be performed during ERCP in one and the same session.BACKGROUND The accuracy of intraductal ultrasonography (IDUS) and endoscopic ultrasonography (EUS) were compared in diagnosing biliary obstruction and in predicting surgical resectability. METHODS Fifty-six patients with biliary obstruction were investigated preoperatively with both conventional EUS and IDUS. The ultrasonographic miniprobe was inserted into the bile duct system through the working channel of the duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). Conventional endosonography was performed with echoendoscopes in a standard technique. Images of endoluminal ultrasonography were prospectively reviewed and compared with intraoperative findings and resection specimen analyses. RESULTS IDUS exceeded EUS in terms of accuracy (IDUS, 89.1%; EUS, 75.6%; P < 0.002), sensitivity (IDUS, 91.1%; EUS, 75.7%; P < 0.002), specificity (IDUS, 80%; EUS, 75%; NS), and T-staging (IDUS, 77.7%; EUS, 54.1%; P < 0.001). In bile duct carcinomas the accuracy rate for lymph node staging using IDUS (60%) is comparable with that using EUS (62.5%). In pancreatic carcinomas, however, lymph node staging using IDUS (13.3%) is significantly (P < 0.002) inferior to EUS (69.2%). Endoluminal ultrasonography may predict the potential resectability of bile duct tumors (IDUS, 81.8%; EUS, 75.6%; P < 0.002). CONCLUSIONS IDUS proved to be accurate in preoperative diagnosing and T-staging of malignant biliary strictures, whereas it is not suitable for lymph node staging. IDUS using miniprobes during ERCP exceeds conventional EUS in terms of depiction of bile duct obstruction, diagnostic accuracy, and sensitivity and in the prediction of surgical tumor resectability. Additionally, different to EUS, IDUS can conveniently be performed during ERCP in one and the same session.

Tumors of the papilla of Vater – inadequate diagnostic impact of endoscopic forceps biopsies taken prior to and following sphincterotomy

BACKGROUND It has been proposed that adenomas of the papilla of Vater are precursors of adenocarcinomas. Duodenoscopy with ERCP and forceps biopsies have substantially improved the morphologic exploration of the major duodenal papilla. Yet there is little and contradictory information as to the diagnostic accuracy of endoscopic biopsies in tumors of the papilla. Moreover, after endoscopic sphincterotomy data on the diagnostic impact of endoscopic biopsies from the papilla are scarce and, in most cases, retrospectively obtained. Thus, the aim of the present prospective and histopathologically controlled study was to assess the diagnostic accuracy of endoscopic biopsies taken from tumors of the papilla before and after sphincterotomy. PATIENTS AND METHODS Forty patients with tumors of the papilla of Vater were included in the study. In each case, a comparison was made between endoscopic forceps biopsy diagnoses prior to and following sphincterotomy and the definitive histological diagnosis after surgical tumor resection. RESULTS Resected tumors were diagnosed histomorphologically as follows: 19 adenocarcinomas (47%), 6 tubular adenomas (15%), 7 villous adenomas (17%), 7 inflammatory non-neoplastic lesions (pseudotumors) (17%), and one adenomyoma (2%). Overall accuracy for preoperative histopathological diagnosis was 62% (25 of 40, 95% CI: 47%-76%) prior to sphincterotomy while it was 70% (28 of 40, 95% CI: 55%-81%) following the procedure. Regarding adenocarcinomas, sensitivity was found to be 21% (4 of 19, 95% CI: 8%-43%) prior to and 37% (7 of 19, 95% CI: 19%-58%) after sphincterotomy while specificity was 100% at both times. CONCLUSIONS Endoscopic forceps biopsies do not allow for reliable preoperative diagnosis of tumors of the papilla of Vater.

Cadaveric "two-in-one" kidney transplantation from marginal donors: experience of 26 cases after 3 years.

Background. Because of the problem of organ shortage, the use of renal transplants from marginal donors has been tested by different procedures. Methods. In our center 26 recipients (59±7 years) underwent double renal transplantation from July 1996 to August 1999 using marginal donors (71±6 years). A special scoring was applied that included donor age, serum creatinine, the grade of glomerulosclerosis, and kidney weights leading to the decision whether single or dual or no kidney transplantation was performed. Results. After an average follow-up of 18±10 months 22 of 26 (85%) double kidney transplant recipients are alive and have functioning grafts. Three patients died with well-functioning grafts. The actuarial 1-year patient and graft survival rate was 94% (n=18), the 2-year rate 92% (n=12). Two patients lost one graft each without becoming dialysis dependent. The average serum creatinine was 1.6±0.5 mg/dl after 12 months (n=17) and 1.9±0.6 mg/dl after 24 months (n=11). Primary nonfunction occurred in 31%, acute rejection within the first 6 months in 14%. Ten patients who received single old grafts according to our score had similar transplant survival rates but worse graft function after 1 year. Conclusions. Transplant function and survival of patients after dual kidney transplantation indicate that this procedure is reasonable to ameliorate the problem of organ shortage. The most crucial point is to establish a widely accepted standardized scoring for the donors leading to single, dual, or refusal of transplantation.

Prognostic value of lymphocyte apoptosis in acute rejection of renal allografts.

BACKGROUND Apoptosis is a cellular phenomenon generally found within rejecting transplants. It may play a role in physiological or therapy-associated deletion of infiltrating lymphocytes or in graft cell destruction. Our study focuses on apoptosis of infiltrating lymphocytes during acute kidney rejection after the initial steroid pulse therapy and on possible prognostic implications. METHODS Renal biopsy specimens of 23 transplant recipients with acute tubulo-interstitial rejection were examined for appearance of apoptosis and compared with 11 transplant biopsies with unspecific organ injury accompanied by lymphocyte infiltration. In all patients, biopsies were performed after steroid pulse therapy, and, after confirmation of rejection, antilymphocytic antibody treatment was carried out. Apoptosis was determined via terminal deoxynucleotidyltransferase-mediated dUTP-digoxigenin nick end labeling analysis and confirmed by electron microscopy. RESULTS Apoptosis of lymphocytes or of tubular epithelium was detected in 11 cases of acute rejection (48%), respectively. Four biopsies showed lymphocytic as well as tubular apoptosis, whereas five sections showed no signs of programmed cell death. In biopsies revealing unspecific injury, tubular cell apoptosis was more frequently found (73%) compared with lymphocyte apoptosis (27%, P<0.05). Most interestingly, patients with a beneficial recovery from acute rejection had a higher proportion of lymphocyte apoptosis compared with patients with poor rejection outcome. The Bcl-2 oncoprotein was widely found within infiltrating lymphocytes without counter-regulating apoptosis. CONCLUSIONS Lymphocyte apoptosis is found as frequently as tubular cell apoptosis in rejecting renal grafts after steroid pulse therapy and might have prognostic value for rejection outcome.

High-frequency oscillation in an adult porcine model

Objective: Controversy exists as to whether high‐frequency oscillatory ventilation can be used on babies and small laboratory animals only, or whether high‐frequency oscillatory ventilation can also be efficient in the adult patient and large (>65 kg body weight) laboratory animals. Moreover, controversy exists as to whether limitations in high‐frequency oscillation efficiency are caused by the size and shape of the bronchial system, by the lack of low impedant intersegmental gas flow in lung parenchyma, or by inappropriate high‐frequency ventilators and ancillary hardware. Therefore, our objective in this study using the adult pig as a model of the adult patient was to test whether the adult airway system is suited to the use of high‐frequency oscillatory ventilation or whether there are geometrical, structural, or functional limitations to efficient ventilation by high‐frequency oscillation. Design: Prospective, controlled, randomized comparison over 8 to 16 hrs of ventilatory management. Setting: Experimental thoracovascular surgery laboratory in a university hospital. Subjects: Fifteen adult, female, house swine (weight 90 to 140 kg). Interventions: We evaluated the ventilatory effect of a wide range of oscillation frequencies (10–15 to 35–45 Hz), tidal volumes (0.5 to 2.2 mL/kg), and bias flow volumes (10 to 70 L/min) at a mean airway pressure of 12 ± 1 cm H2O in anesthetized and relaxed pigs who did not have lung injury. Measurements and Main Results: Arterial blood gases are mainly dependent on tidal volume, frequency, and mean airway pressure. A threshold bias flow volume of 35 ± 5 L/min is required to prevent CO2 rebreathing. In the group of lightweight animals (65 to 99 kg), the most efficient frequency band for CO2 elimination was ∽25 Hz. The most efficient frequency band for arterial oxygenation was found to vary between individuals more than the most efficient frequency band for CO2 elimination. In the group of heavy animals (100 to 140 kg), no most efficient mean frequency could be assessed, probably because the excitation system was limited. We confirmed that tidal volume on its own had an effect on CO2 elimination (“tidal‐volume effect”), although CO2 elimination was mainly determined by the product of tidal volume and oscillation frequency (oscillated minute volume), at least up to a critical frequency. Beyond that frequency, CO2 elimination could not be enhanced. The most efficient mean airway pressure in unimpaired lungs was assessed at 12 ± 1 cm H2O. Conclusions: Adult pigs with a body weight in the range of the weight of clinical adult patients can be ventilated by high‐frequency oscillation at tidal volumes smaller than, equal to, or slightly more than anatomical deadspace. The most efficient frequency for gas exchange varied between individuals. Tidal volume had an enhancing effect on CO2 elimination. The frequency dependency of Pao2 may have been related to a frequency‐dependent structural remodeling of the airway system, which occurred even though the mean airway pressure was kept constant. These results demonstrate that failure of adequate ventilation by high‐frequency oscillation is caused by a) CO2 rebreathing, b) the avoidance of an appropriate alveolar recruitment strategy, and c) an underpowered, high‐frequency ventilatory system (oscillator) that is unable to deliver appropriate pressure oscillations. These limitations led to insufficient CO2 elimination and/or inadequate arterial oxygenation. (Crit Care Med 1994; 22:S37‐S48)

Influence of Heme Oxygenase-1 on Microcirculation After Kidney Transplantation

BACKGROUND Cytoprotective proteins, such as heme oxygenase-1 (HO-1), play a decisive role in ischemia-reperfusion injury during kidney transplantation. The aim of this study was to investigate the impact of heme oxygenase-1 on microcirculation and on ischemia-reperfusion injury in an isogenic kidney transplantation rat model. MATERIALS AND METHODS Seventy male Lewis rats were distributed into three groups. In Group 1(control), the kidneys were only mobilized. In Groups 2 and 3, bilateral nephrectomy was performed, and a kidney from another Lewis rat was orthotopically transplanted on the left side. The donor animals in Group 3 received preconditioning with the HO-1 inductor hemin. 24 h after reperfusion graft function and morphology were examined. Microcirculation was investigated by in vivo microscopy of the renal surface 1 h after reperfusion. RESULTS HO-1 preconditioning led to significantly lower serum creatinine and serum urea, as well as less histological damage and inducible nitric oxide synthase expression. Microcirculation was improved by a significant enlargement of the vascular diameter and an increase of the capillary flow. CONCLUSIONS Treatment with hemin improves microcirculation by induction of HO-1 and reduces ischemia-reperfusion injury after kidney transplantation. HO-1 induction was shown to be a promising approach in the preconditioning of donor kidneys.

Long-term follow-up of double kidney transplantation using a score for evaluation of marginal donors*.

To face the problem of organ shortage, marginal grafts from 36 donors which had been refused for single transplantation were used for double‐kidney transplantation (D‐KTX). The residual kidney function was evaluated by the Muenster double kidney score. In a 5‐year period kidneys from 57 marginal donors were transferred to our center. According to the Muenster double kidney score, the kidneys were distributed to single, double or refusal of transplantation. Sixteen male and 20 female donors were used for D‐KTX (70±9.3 years, range 53–86). Thirty‐six recipients (23 male, 13 female; 60.5±6.9 years) were double‐grafted within a mean cold ischemic time of 19.3±3.4 h. Immunosuppression varied according to human leukocyte antigen (HLA)‐mismatch. Graft and patient survival was observed up to 5 years. Initial graft function rate was 69%. Two recipients had a primary nonfunction (5.5%) and nine recipients suffered from delayed graft function (DGF; 25%). One‐, 2‐, 3‐year creatinine values were 1.6 ± 0.5, 1.9 ± 0.6 and 2.2 ± 0.7 mg/dl, respectively. One‐, 2‐, 3‐, 4‐ and 5‐year function rate was 93.7%, 93.5%, 81.8%, 76.4% and 55%, respectively (n = 32, 31, 22, 17 and 9). Acute rejection rate was 19%. 4 grafts were lost to chronic rejection (months 22, 25, 28, 48). Six (16%) died in long‐term follow‐up because of pneumonia (n = 2), carcinoma of the lung (n = 1), cardial complications (n = 2) and multiorgan failure (n = 1). D‐KTX is a safe way to face the problem of organ shortage. However, a score for preoperative evaluation of marginal kidneys for single, dual or refusal of transplantation is essential.

Duodenal duplication cyst mimicking pancreatic cyst in a patient with pancreatitis.

Pancreatic pseudocyst is a common complication of pancreatitis that often confounds patient management. Reported here is a case of an enteric duplication cyst within the duodenal wall of a 16-year-old boy that lead to recurrent episodes of pancreatitis because of intermittent obstruction of both the bile duct and the pancreatic duct. The cyst was the cause and not the result of pancreatic inflammation.

Nephron-sparing surgery of a low grade renal cell carcinoma in a renal allograft 12 years after transplantation.

Renal cell carcinoma (RCC) occurring in renal allografts after cadaveric kidney transplantation has rarely been observed. RCC accounts for 2.3 % of all malignancies in the general population, but up to 4.8 % of malignancies in renal transplant recipients. Most have been reported in the patient’s own diseased kidneys, whereas RCC in the renal allograft occur in only 10 %. Here, we describe an organ-preserving surgical technique of a malignant renal tumor in a kidney allograft using an harmonic scalpel (Ultracision©) for tumor enucleation. Furthermore we demonstrate by DNA microsatellite analysis the tumor’s genetic origin as donor related. Collectively, we suggest that patients with a well defined low grade RCC in the kidney allograft and altogether low malignancy and good allograft function should only undergo an organ-preserving procedure and short-term postoperative screening.

sTNF-RII: is it useful for the early diagnosis of rejection and for prognosis after renal transplantation?

Abstract Changes in soluble tumour necrosis factor receptor II (sTNF‐RII) correlate with transplant rejection, and it increases in the course of sepsis. These changes might help to identify rejection early, and thus lead to more effective treatment. Serum and urine sTNF‐RII levels were measured in 70 patients during the first 3 weeks after kidney transplantation and correlated with clinical and laboratory findings. Retrospectively, three groups were identified: I. stable transplant function (n= 23), II. at least one rejection episode (n=38) and III. other complications (infection or reperfusion injury) (n= 9). The pre‐operative maximum for serum sTNF‐RII was 22.4±10.7 ng/ml. In group I it decreased to 9.5±6.7 ng/ml on day 6 after transplantation (P<0.01), while in group II sTNF‐RII serum levels were significantly higher on day 6 (24.9±15.0 ng/ml, P<0.01). High levels of sTNF‐RII in serum (>40 ng/ml for at least 2 days) predicted a higher risk of an unfavourable outcome. High serum levels of sTNF‐RII are not specific but seem to be a prognostic indicator of a complicated course; sTNF‐RII in urine has no diagnostic value.