The influence of periarterial papaverine application on intraoperative renal function and blood flow during laparoscopic donor nephrectomy in a pig model

Background: The transplantation of live donor kidneys harvested laparoscopically is associated with a higher incidence of delayed graft function than the transplantation of grafts harvested via the open technique. The delay is believed to be due to a decrease in renal blood flow during laparoscopic donor nephrectomy (LDN). The aim of this study was to evaluate whether renal function and blood perfusion can be enhanced by the periarterial application of papaverine during LDN. Methods: Renal function and blood flow were studied in a porcine model that included a total of 24 pigs (20–30 kg). In 12 of the pigs, urine output and creatinine clearance were determined as measures of renal function. In the other 12 pigs, renal blood flow was determined using fluorescent-labeled microspheres. In each group, the pigs were randomized into two subgroups, one with and one without a perivascular injection of 50 mg papaverine. Results: As compared to the controls, the animals receiving papaverine had a significantly higher urine output (3.1 ± 1.6 vs 0.9 ± 0.45 ml/h/kg; p = 0.02), superior creatinine clearance (2.22 ± 0.5 vs 0.95 ± 0.1 ml/min/kg; p = 0.038), and enhanced renal blood flow (4.9 ± 2.2 vs 2.1 ± 0.8 ml/min/g; p = 0.008). Conclusions: When applied to the tissue surrounding the renal artery, papaverine substantially improves renal function and blood flow during laparoscopic live kidney donation. Whether graft optimization during kidney procurement also translates into improved posttransplantation function remains to be established. Presented at the 8th World Congress of Endoscopic Surgery, Society of American Gastrointestinal Endoscopic Surgeons (SAGES) meeting, New York, NY, USA, 13–16 March     

Bilateral multifocal renal oncocytoma

Renal oncocytoma is a rare benign tumor. Bilateral and multifocal renal oncocytoma has rarely been described in childhood. We report a 12-year-old girl who presented with massive left renomegaly and who was found to have bilateral cystic kidneys. A left nephrectomy was undertaken because of the renal enlargement, the radiological evidence of extensive disease, and to make a diagnosis. A diagnosis of multifocal oncocytoma was made after detailed histological examination.     

Arterial hypertension following renal transplantation in children—a short-term study

Systemic arterial hypertension is a common complication among transplanted patients. The objective of this study was to investigate the risk factors for arterial hypertension after kidney transplantation in children. A retrospective study was carried out of 70 kidney transplants performed on patients under 18 years of age at the Hospital do Rim and Hipertensão, from January 1998 to June 2001. At the end of 6 months post transplant, the patients were classified into either normotensive (n=31) or hypertensive (n=39) groups. The following potential risk factors for arterial hypertension were studied: (1) hypertension before transplantation; (2) the glomerular filtration rate (GFR) at 1, 3, and 6 months post transplant; (3) acute rejection episodes; (4) cumulative dose of corticosteroids; (5) the presence of native kidneys; (6) symptomatic renal artery stenosis; (7) cold ischemia time greater than 24 h; (8) age and sex of the donor; (9) age of the recipient; (10) transplant type (living related or cadaveric donor); (11) the body mass index of recipients at the end of the follow-up period; and (12) delayed graft function. The two groups were comparable in terms of the etiology of renal insufficiency, age, gender, and immunosuppressive drugs. Among the risk factors studied, the sole factor showing a statistically significant association with arterial hypertension was the GFR at 3 and 6 months after transplantation. In the group of normotensive patients, GFRs were 92±29 and 83±20 ml/min per 1.73 m² at 3 and 6 months, respectively, whereas in the hypertensive patients, GFRs were 74±23 and 70±21 ml/min per 1.73 m² respectively. Hence, only the lower GFR can be considered a risk factor for hypertension in children within our sample. However, arterial hypertension might be a risk factor for the early onset of chronic allograft nephropathy; in this case, hypertension should be considered the cause of lower glomerular filtration. Our data do not permit us to distinguish between these two hypotheses. The known risk factors for hypertension following renal transplantation in adults were not confirmed in the present study. It remains unclear to us as to whether this means the etiology of hypertension differs in children, or if this is the result of a bias in patient selection.     

Cyclosporine absorption profiles in pediatric kidney and liver transplant patients

Cyclosporine absorption profiling uses either the area under the concentration curve in the first 4 h post dose, AUC(0–4), or the concentration 2 h post dose (C2) to optimize immunosuppression in adult kidney and liver transplantation. We characterized C2 versus AUC(0–4) relationships over time after transplant and across transplant indications in 56 pediatric transplant patients. There were 36 kidney transplant patients aged 9.7±3.9 years. Nineteen of these patients were studied in the de novo period on day 7 post transplant and 17 in the maintenance phase more than 1 year post transplant. In addition, 20 liver transplant patients aged 8.9±4.2 years were studied in the maintenance phase. All patients had five blood samples collected over the 12-h dose interval that were analyzed by validated assay methods at a central laboratory. Pediatric C2 values were 1,463±658 ng/ml for de novo kidney, 954±322 ng/ml for maintenance kidney, and 619±339 ng/ml for maintenance liver transplant patients. C2 was a strong predictor of AUC(0–4) in all three pediatric groups, with coefficients of determination (r ²) ranging from 0.861 to 0.936. Although data were limited from the de novo period, the C2 versus AUC(0–4) regression was consistent over time after transplant and between transplant indications, with a regression slope of 2.50 in de novo kidney, 2.54 in maintenance kidney, and 2.76 in maintenance liver transplant recipients. These slopes were also comparable to that in adult maintenance kidney transplant patients (2.60). In conclusion, C2 versus AUC(0–4) relationships demonstrated consistency over time (de novo vs. maintenance phase), between transplant indications (kidney vs. liver), and across age groups (pediatric vs. adult patients). Average C2 values achieved with current pediatric cyclosporine dosing practices cluster around the target C2 ranges recommended for adults.     

The efficiency of humoral immune transfer depends on both the graft and the immunosuppressive treatment

The present study was designed to compare the efficiency of adoptive transfer of humoral immunity after liver, kidney, and heart transplantation in relation to the number of passenger lymphocytes, and to estimate the risk of a detrimental effect and the chance of a beneficial effect. Hepatitis B virus surface-antigen-vaccinated brown Norway rats (BNs) and AxC 9935 Irish (ACI rats) served as donors, and naïve Lewis (LEW) rats as recipients. The liver grafts contained 100 times more passenger lymphocytes than heart grafts, and the kidney grafts approximately ten times more, indicated by monoclonal CD45 antibody staining. Transient anti-HBs immunity did occur after transplantation of all three organ grafts. In all rejecting groups, the serum recipient-to-donor anti-HBs titer ratio (R/D ratio) was below 0.10%, with heart recipients showing half the level (0.05%) of liver recipients (0.09%). Under immunosuppression, R/D ratio doubled in liver or kidney recipients, but remained unaffected in heart recipients. Immune transfer was most efficient in immune-suppressed liver recipients in the spontaneously tolerant strain combination as indicated by a significantly higher R/D ratio (0.32%) and a longer titer persistence (up to 9 weeks) than in all other groups. Therefore, mainly liver and kidney graft recipients carry a risk, but also a chance of benefiting from the transfer of donor-derived immunity.     

Open radio-frequency thermal ablation of renal VX2 tumors in a rabbit model using a cooled-tip electrode: feasibility,safety, and effectiveness

The purpose of this study was to evaluate the feasibility, safety, and effectiveness of radio-frequency (RF) ablation using an internally cooled-tip electrode on renal VX2 tumors implanted in rabbits. Thirty-three rabbits with implanted renal VX2 tumors were divided into two groups: an RF ablation (RFA) group (n=27) and a control group (n=6). In the RFA group, RFA was performed on 27 implanted VX2 tumors using a cooled RF electrode and they were divided into three subgroups according to the follow-up period: acute (1–3 days, n=12); subacute (1–4 weeks, n=9); and chronic (2–7 months, n=6). Contrast-enhanced spiral CT was performed before the RFA and at the day, day 3, weeks 1, 2, 4, and months 2 and 7, after the RFA. The therapeutic efficacy was evaluated by the survival rate, CT, and pathologic findings. The RFA of renal tumors was technically successful in each instance. Complete tumor ablation was achieved in 22 of the 27 rabbits (81.5%) in the RFA group: 5 rabbits survived longer than 8 weeks without any evidence of viable tumor (18.5%) and 17 rabbits were found free of viable tumors when killed (63.0%). Five rabbits showed local tumor relapse and/or hematogenous lung metastasis after ablation (a recurrence rate of 18.5%). There were 11 (40.7%) complications related to the procedure. This experimental study demonstrates the feasibility of RFA therapy to treat renal VX2 tumors in rabbits, although RFA for central tumors carries some major potential complications, including renal arterial injury. Electronic Publication     

肾结核的CT诊断

目的 探讨肾结核的CT表现及其诊断价值。方法 回顾性复习了29例肾结核的CT检查所见。结果 CT检查肾结核（重点探讨临床型肾结核）依病情发展的琐阶段及相应的病理变化而出现不同的CT表现。“花瓣”状的铮低密度影及钙化是肾结核较为特征性表现,肾积水,肾功能丧失。自截肾是肾结核的晚期表现。结论 CT检查对肾结核具有较高的诊断价值。多数病例结合临床和实验室资料可获得正确诊断。     

Pediatric excretory MR urography: comparative study of enhanced and non-enhanced techniques

Our purpose was to compare the quality of ureteral imaging in pediatric patients using two different MR sequences: the non-enhanced heavily T2-weighted (W) turbo spin-echo sequence (TSE) and the gadolinium-enhanced T1W fast-field-echo sequence (T1 FFE). An experimental study on three pigs was first performed. The TSE, before and after furosemide injection, was followed by the T1 FFE sequence. The clinical study included 11 infants and 10 children. With some modifications the same MR parameters and techniques were used as in the animal study. The TSE with TR 8000 ms and TE 650 ms implied 6 radial stacks each of 40 mm thickness. The T1 FFE included TR 18 ms, TE 2.9 ms, flip angle 60 , and 50 slices with thickness 0.7 mm. After post-processing, image reconstructions qualitative and quantitative analysis were performed. Complete visualization of the ureters was achieved in 35 of 42 (83%) cases. Seventy-four percent of the ureters were completely visualized with T1 FFE compared with only 19% with TSE. Sixty-nine percent of the ureters were better imaged with T1 FFE than TSE and 21% equally well imaged. Four ureters (10%), either obstructed or due to poor renal function, were better imaged with TSE. The two sequences are complementary. Visualization of non-obstructed ureters is excellent with T1 FFE and the sequence is superior to TSE. The TSE, however, may be equal to or even better than T1 FFE in visualizing obstructed ureters or ureters draining malfunctioning kidneys. Electronic Publication     

Vascular lesions of the renal sinus

The renal sinus contains within it the collecting system of the kidney as well as lymphatics, nerves, and renovascular structures. This area may be affected by a large variety of pathological conditions arising from the various tissues in this site. Vascular lesions of the renal sinus are uncommon and may present clinically with acute symptoms and on imaging as a mass lesion. Awareness of the different vascular lesions affecting this area is essential for establishing the correct diagnosis and for appropriate treatment. The role of computed tomography is emphasized because it is the most commonly used modality to evaluate acute abdominal conditions as well as suspected renal masses, and the diagnosis can usually be made without the need for additional imaging modalities.All departments affiliated to the Sackler School of Medicine, Tel Aviv University, Israel     

Ablation of Symptomatic Cysts Using Absolute Ethanol in 11 Patients with Autosomal-Dominant Polycystic Kidney Disease

Objective

To evaluate the effects of cyst ablation with absolute ethanol in autosomal-dominant polycystic kidney disease (ADPKD) patients with symptomatic cysts.

Materials and Methods

Using absolute ethanol, cyst ablation was performed in 11 patients with documented ADPKD who suffered cyst pain refractory to medical treatment. An ethanol solution was instilled into the largest symptomatic cysts through a catheter. We assessed the therapeutic efficacy of the procedure by tracking subjective pain relief during a 3 to 24-month follow-up period after ablation.

Results

At follow-up, we found that the duration of subjective pain relief was 12 to 24 months in seven patients, 4 to11 months in one, and less than 3 months in three.

Conclusion

Selective ablation of a symptomatic cyst may be a valid option in managing chronic pain caused by one or a few large cysts in ADPKD patients.