Clinical follow-up of children with low differential function on diuretic renogram.

OBJECTIVE: One of the most challenging dilemmas in pediatric urology today is to determine the optimal management of children with hydronephrotic kidney secondary to suspected ureteropelvic junction obstruction. Some believe in early surgical management while others believe in conservative management. To better define these issues, the authors retrospectively reviewed 101 patients with hydronephrosis. MATERIAL AND METHOD: The present study was approved by The Children 's Hospital of Philadelphia 's institutional review board and waiver of informed consent for retrospective study. One hundred and one children (72 males and 29 females) of ages of 6 days to 19 years with hydronephrosis with suspected UPJ obstruction underwent diuretic renograms with 99mTc DTPA. The authors classified the differential renal function into three groups: Group I: 0-15%, Group II: 16-30%, and Group III: 31-46%. RESULTS: Forty-one patients with conservative management, 32% (5 in group I: 1 in group II and 7 in group III) showed improved differential renal function. Non-operative management patients from group I and II showed no deteriorating renal function and only one case from group III had deteriorating renal function. In operative management, 78% of group I, 41% of group II, and 25% of group III showed improvement in differential renal function. In the remaining operative cases, six showed deteriorated differential renal function [1 (4%) group I: 3 (18%) group II: 2 (10%) group III] whereas 24 remained stable or unchanged [Group 1: 4 (17%), Group II: 7 (41%), Group 111: 13 (65%)]. CONCLUSION: The authors recommended conservative management for children with differential renal function between 16-46%.

Tc-99m DTPA scintigraphy in soft tissue tumor.

Tc99m-DTPA scintigraphic study were done in Centre For Nuclear Medicine and Ultrasound (CNMU) Mymensingh presented with palpable soft tissue mass. All the patients referred to CNMU for ultrasonic evaluation of the mass. Taking proper consent form patient and we did the Tc-99m DTPA scanning of the masses. The study was carried out using Tc-99m DTPA in three phases dynamic, blood pool after 5 min, followed by a late scan after 2 hr. The uptake was categorized as consistently positive, initially positive but latter (progressively) negative, initially negative but latter (progressively) positive and consistently negative. Among our studied cases there were both benign and malignant lesion that were proved by histopathology after excisional biopsy. Two cases were inconclusive. Histologically proven lipoma showed no uptake of DTPA considered as consistently negative. Two cases of rhabdomyosarcoma showed consistently positive.

Comparative study of renal function between standard and modified anatrophic nephrolithotomy by radionuclide renal scans.

OBJECTIVE: To compare the changes in renal function after surgery between standard and modified anatrophic nephrolithotomy using the technetium 99m-DTPA renal scan in patients with complex staghorn calculi. MATERIAL AND METHOD: From July 2001 to March 2002, standard anatrophic nephrolithotomy (sANL) was performed in 7 patients with complex staghorn calculi and modified anatrophic nephrolithotomy (mANL) was performed in another group of 8 patients with the same condition. Preoperative and postoperative renal function were assessed by technetium 99m-DTPA renal scan. RESULTS: Mean patient age was 41 years in the sANL group and 45 years in the mANL group. Male to female ratio was 4:3 in the sANL group and 5:3 in the mANL group. Median operative time was 205 minutes in the sANL group compare with 180 minutes in the mANL group (P = 0.03). Median estimated blood loss was 300 ml. in the sANL group and 275 ml. in the mANL group (P = 0.17). Median percent reduction of GFR on the operated kidney was 9.13 (-30.03 to -3.15) in the sANL group and 27.25 (-41.81 to -1.55) in the mANL group (P = 0.13). Residual small stone was seen in one patient of the sANL group and ESWL was performed for stone fragmentation. There were no serious short-term complications. CONCLUSION: The average operative time of sANL was longer than mANL however, sANL preserved more renal function than mANL. This study suggested that sANL should be the procedure of choice in patients who have compromised renal function.

Captopril for prevention of contrast-induced nephropathy in diabetic patients: a randomised study.

Contrast-induced nephrotoxicity is an important cause of hospital-acquired acute renal insufficiency. Different modalities have been used to prevent contrast induced-nephrotoxicity namely saline infusion, mannitol, furosemide, calcium channel blockers, atrial natriuretic factor and dopamine infusion with variable success. The possible role of medullary ischaemia mediated by renin angiotensin system in genesis of contrast-induced nephrotoxicity prompted us to investigate the role of captopril (a sulfhydryl group containing angiotensin-converting enzyme inhibitor) in its prevention. Seventy-one patients of diabetes mellitus undergoing coronary angiography were included in the study. Patients randomised to receive captopril, received the drug in a dose of 25 mg thrice a day for three days, starting one hour prior to angiography while the patients in the control group underwent angiography in a routine manner without receiving captopril. Following angiography, patients in the control group developed a significant increase in serum creatinine and blood urea nitrogen levels, as compared to those who received captopril. Contrast-induced nephrotoxicity (i.e. a rise of 0.5 mg/dL in serum creatinine) developed in 29 percent of the control group. Administration of captopril reduced the risk of development of contrast-induced nephrotoxicity by 79 percent. Glomerular filtration rate as measured by Tc DTPA renal scanning prior to and 24-72 hours following angiography demonstrated a mean fall of 9.6 ml/min in the control group while those in the captopril group had a mean increase of 13 ml/min in glomerular filtration rate. We conclude that abnormalities of renal perfusion possibly mediated by renin angiotensin system are responsible for development of contrast-induced nephrotoxicity. Administration of the angiotensin-converting enzyme inhibitor, captopril, offers protection against development of contrast-induced nephrotoxicity.

99m Tc DTPA scan as a diagnostic marker of acute rejection in renal transplantation.

Forty renal transplant recipients were subjected to 99m Technicium Diethylene triamine pentacetic acid (DTPA)scans at regular intervals & whenever there was suspection of rejection. Serial scans of a group of 15 recipients from immediate post transplant period till withdrawal of cyclosporine were analysed separately & the results compared to with single scan analysis. The sensitivity & specificity of DTPA scan in the absence of acute tubular necrosis (ATN) was 94.1% & 87.5%, while the positive & negative predictive values were 88.8 & 93.3% respectively. Sensitivity & specificity of serial scan analysis (88.8% and 75%) in early post transplant period was higher than that of interpretation of single scan (75% & 66%). Serial scan changes predated clinical rejection during cyclosporine withdrawal period. We conclude that DTPA scan is both a sensitive & specific non-invasive diagnostic marker of acute rejection in absence of ATN & serial scans during early post transplant period & at the time of cyclosporine withdrawal are helpful in detecting the rejection accurately & at the earliest.

Direct estimation of absolute glomerular filtration rate from dynamic renal scintigraphy using gamma camera.

Absolute glomerular filtration rate (GFR), which can serve as a useful parameter of renal function, is not applied in clinical practice due to various technical constraints. We estimated GFR in 20 subjects (10 controls, 10 patients) by two different techniques simultaneously with a single intravenous injection of TC99m DTPA. The GFR results obtained by a conventional plasma clearance technique were compared with that of a simpler, scintigraphic technique which does not require any blood or urine sample, and these were found to correlate significantly (r = 0.75, p less than 0.001). The linear relationship between the fraction of the dose injected taken up by the kidneys during the parenchymal phase of the dynamic imaging study and the overall plasma clearance was also found to be significant (r = 0.932, p less than 0.001) our study shows that reliable estimation of absolute GFR is possible from the routine dynamic renal scinti-scanning procedure using the gamma camera - computer system, and hence might prove applicable in clinical practice.