MAG3 Renal Scan Research Articles

The Impact of Ischemia on Long-Term Renal Function After Partial Nephrectomy in the Two Kidney Model

To determine whether on-clamp partial nephrectomy (ON-PN) has any significant impact on long-term renal function in a two kidney model. From November 1999 to July 2013, 607 patients underwent PN at our institution. After excluding patients with solitary kidneys, multiple renal masses, and follow-up less than 90 days, 331 remained. Patient demographics were assessed, as was renal function based on pre- and postoperative mercaptoacetyltriglycine (MAG-3) renal scans and change in estimated glomerular filtration rate (eGFR) using the preoperative and most recent recorded creatinine levels. There were a total of 236 patients who underwent ON-PN and 95 who underwent off-clamp PN (OFF-PN) during the study period. The longest follow-up was 12.6 years with mean follow-up of 3 years. Mean ischemia time of patients undergoing ON-PN was 25 minutes (range 8-63 min). No differences were noted between the ON-PN and OFF-PN cohorts with respect to estimated change in eGFR (ON-PN: -6.07 mL/min/1.73 m(2) vs OFF-PN: -6.00 mL/min/1.73 m(2), P=0.69). No differences were noted in the % change in the MAG-3 renal scans (ON-PN: -0.77% vs OFF-PN: -1.1%, P=0.94). A post hoc sensitivity analysis of the same two variables stratified by age revealed no differences in change in estimated GFR or % change in differential function on renal scan. In the two kidney model, ischemia does not appear to affect long-term renal function outcomes after PN. These data provide evidence that ON-PN is perfectly acceptable in the appropriately selected patient with two kidneys.

An analysis of long-term occurrence of renal complications following pediatric pyeloplasty

ObjectiveFew reports discuss post-pubertal renal complications after pyeloplasty. We analyzed long-term complications, such as decreased renal function (RF) measured by serum creatinine (SCr), hypertension (HTN), or proteinuria (protU) following pediatric pyeloplasty. Subjects and methodsWe retrospectively investigated 257 patients who underwent dismembered pyeloplasty due to ureteropelvic junction obstruction from January 1986 to December 2001. Medical history, preoperative and postoperative blood pressure, urinalysis, and SCr results were reviewed. ResultsFifty-five patients (47 male, 8 female) who were followed up for at least 10 years with post-pubertal follow-up data available were analyzed. Seven (12.7%) patients were diagnosed with HTN, and 10 (18.2%) with protU. The grade of hydronephrosis decreased, and the differential RF measured by MAG-3 renal scan significantly increased at final analysis (p < 0.001). Presence of preoperative symptoms (p = 0.034), and SCr elevation (p = 0.018) showed correlation with HTN. HTN took 15.7 (±5.8) (7–25) years, and protU detection took 16.2 (±5.9) (6–23) years, with the highest incidence of both HTN and protU between 15 and 20 years postoperatively. ConclusionAccording to our investigation, a prudent evaluation of signs of RF decrease at 10 years after surgery, and then every 5 years, until 20 years should be recommended, although further studies are necessary.

Use of Early Postoperative MAG3 Renal Scan To Predict Long-Term Outcomes of Renal Transplants

A Tc-99m mercaptoacetyltriglycine renal scan has been used to evaluate perfusion and excretory function of renal allografts. A Tc-99m mercaptoacetyltriglycine renal scan has been reported to correlate with early allograft outcomes. This study was done to determine whether a Tc-99m mercaptoacetyltriglycine renal scan has any relation with long-term renal transplant outcomes. A total of 311 consecutive kidney transplant recipients were included in the study. All had Tc-99m mercaptoacetyltriglycine renal scans on posttransplant days 3 and 7. Patterns of the renography curve was graded as follows: 0=normal perfusion and excretion; 1=normal perfusion, reduced excretion; 2=normal perfusion, flat excretion; and 3=reduced perfusion and rising curve. Early postoperative Tc-99m mercaptoacetyltriglycine scintigraphy findings were correlated with serum creatinine values, acute rejection episodes, and long-term graft survival. A Tc-99m mercaptoacetyltriglycine renography of a deceased-donor kidney transplant showed a significantly higher grade on both days 3 and 7 than did live-donor kidney transplant (P < .001). Serum creatinine was positively correlated with the renography grades on days 3 and 7. The acute rejection rate was higher in the renography on days 3 and 7. Grade 2 renography on day 3 showed a significantly higher graft failure rate compared with the other grades (8.8% vs 8.6% vs 31.6% vs 7.3%; P = .014). Also, the renography showed the worst 5-year graft survival rate (95.9% vs 93.3% vs 89.5% vs 94.1%; P = .019). There were no differences in the graft failure rate or in graft survival rate according to the Tc-99m mercaptoacetyltriglycine renography grades on day 7. Our data show that a Tc-99m mercaptoacetyltriglycine renography grade correlate not only with early postoperative kidney function and incidence of acute rejection, but also with long-term outcomes of a renal allograft. A grade 2 renography pattern, with normal uptake and flat excretion, indicates a dismal prognosis for the long-term allograft survival.

Renal Autotransplantation for Iatrogenic High-Grade Ureteric Stricture

A 47-year-old Hispanic woman developed a chronically obstructed left kidney, due to a long-segment ureteric stricture deemed not amenable to reimplantation, following left ovarian cyst excision in 2004. Therefore, a ureteral stent requiring exchange every 3 months was necessary, due to hydronephrosis, recurrent urosepsis, chronic pain, and a poor quality of life. Her medical history was complicated by hypertension, poorly controlled diabetes mellitus, and microalbuminuria, suggesting early diabetic nephropathy. A left nephrectomy was recommended. This was deferred, due to concern for progressive kidney failure associated with her comorbidities. A radionuclide Tc-99m MAG3 renal scan revealed differential perfusion as follows: 44% left kidney and 56% right kidney, with symmetrical uptake on the renogram phase and delayed excretion on the left, which were correctted following furosemide administration. A left ureteronephrectomy with autotransplantation of the left kidney and ureteroneocystostomy was performed in 2009. Since then, the patient has experienced no further complications or need for invasive procedures, with excellent diabetic control and stable renal function (eGFR > 60 mL/min/1.73 m2). This technique is seldom employed in the surgical management of complex ureteral injuries, but may be an alternative for appropriate cases.

V496 ROBOTIC UPPER POLE HEMINEPHRECTOMY FOR A CHRONICALLY OBSTRUCTED DUPLICATED COLLECTING SYSTEM IN A SOLITARY KIDNEY

You have accessJournal of UrologyTransplantation, Urolithiasis & Hydronephrosis1 Apr 2011V496 ROBOTIC UPPER POLE HEMINEPHRECTOMY FOR A CHRONICALLY OBSTRUCTED DUPLICATED COLLECTING SYSTEM IN A SOLITARY KIDNEY Wesley White, Brent Hardin, Ryan Pickens, and Frederick Klein Wesley WhiteWesley White Knoxville, TN More articles by this author , Brent HardinBrent Hardin Knoxville, TN More articles by this author , Ryan PickensRyan Pickens Knoxville, TN More articles by this author , and Frederick KleinFrederick Klein Knoxville, TN More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.592AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Complete or incomplete duplication of the ureter is one of the most common congenital malformations of the urinary tract. In some cases of complete ureteral duplication, the upper pole moiety is obstructed and non-functional while the lower pole moiety demonstrates reflux. Management of the upper pole moiety includes either upper pole heminephrectomy or reimplantation. Failure to address the upper pole ureter during lower pole reimplant can lead to recurrent obstruction and infection. METHODS A 49 year old female presented with recurrent right flank pain, fevers, and nausea. The patient had previously undergone bilateral ureteral reimplantation for vesicoureteral reflux at an outside hospital 5 years prior. Follow-up VCUG demonstrated no recurrent reflux. Cross-sectional imaging demonstrated an atrophic left kidney as well as a duplicated right kidney. A dilated right upper pole moiety was apparent. MAG3 renal scan confirmed the poorly functioning nature of the left kidney. The patient was subsequently taken to the operating room for planned robotic upper pole heminephrectomy. Following cystoscopy with retrograde pyelogram and JJ stent placement of the lower pole ureter, the colon and duodenum were reflected medially. The large upper pole ureter was immediately apparent. The obstructed ureter was dissected from the lower pole of the ureter cephalad towards the renal hilum. The obstructed system was dissected away from the lower pole collecting system and parenchyma of the kidney. The upper pole moiety was next opened and excised. The operative bed was rendered hemostatic with use of the argon beam and a topical hemostatic agent. A drain was placed and the kidney retroperitonealized. RESULTS Operative time was 134 minutes. Estimated blood loss was 25mL. There were no intraoperative or postoperative complications. Length of hospitalization was 3 days. The J-P drain and stent were removed at one week following surgery. At 8 months following surgery, the patient denies any pain or fevers. Renal function is within normal limits. CONCLUSIONS Complex upper pole heminephrectomy may be safely and efficiently addressed in a minimally invasive fashion. Use of the robotic operating platform affords improved visualization and articulation when performing hilar dissection and excision of the non-functioning moiety. Care must be taken to preserve the lower pole ureter including preoperative ureteral catheter or stent placement. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e202 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wesley White Knoxville, TN More articles by this author Brent Hardin Knoxville, TN More articles by this author Ryan Pickens Knoxville, TN More articles by this author Frederick Klein Knoxville, TN More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Magnetic resonance nephrography for planning of laparoscopic partial nephrectomy in a pediatric case of ureteral triplication

We present the case of ureteral triplication with vesicoureteral reflux into the lowest and middle pole in a 5-year-old girl. Magnetic resonance (MR) nephrography depicted loss of function of the lowest pole, which could not be assessed through MAG3 renal scan. Morphologic analyses revealed organ structure and vascular anatomy in superior quality. A laparoscopic partial nephroureterectomy of the lower pole was performed. Intraoperative findings correlated exactly with morphologic data obtained through MR nephrography. Dynamic MR nephrography should be considered as diagnostic tool of choice for selected kidney anomalies before surgery.

A 7% Decrease in the Differential Renal Uptake of MAG3 Implies a Loss in Renal Function

To address the fact that a decrease in the relative renal uptake of 99mTc-mercaptoacetyltriglycine (MAG3) on serial MAG3 scans may indicate a loss of function and require a change in management by providing guidance as to what constitutes a meaningful change in serial relative function measurements as well determining the normal variation of other common MAG3 renogram parameters. A prospective study was conducted in 24 male urology patients with stable renal function. The mean age was 66.5 ± 7.9 (SD) years; the mean serum creatinine was 1.38 ± 0.57 (SD) mg/dL, and the MAG3 renal scans were performed a mean of 11 ± 8 days apart. Each MAG3 scan included a measurement of relative function as well as the time to maximum counts and 20 minutes to maximum count ratios for both cortical and whole kidney regions of interest. The Pearson and intraclass correlations for the baseline and repeat measurements of relative renal function were both 0.98. Bland-Altman plots showed no bias between the baseline and repeat relative uptake measurements. The mean difference between 2 repeated measurements of the relative MAG3 uptake was 0.04 ± 2.88% (SD) for the left kidney and 0.08 ± 3.07% (SD) for the right kidney. Comparable results were obtained for the other renogram parameters. Measurements of relative renal uptake of MAG3 and common renogram parameters are highly reproducible; a decrease in relative uptake ≥7% (ie, 50%-43%) implies a loss in renal function.

Nephron Sparing Surgery for Central Bilateral Nephroblastoma

Purpose Involvement of the renal hilus is the most common reason for nephrectomies in stage V nephroblastoma. We present the technique of longitudinal partial nephrectomy for concerning tumors as special subtype of renal salvage procedures. Material and Methods Five patients with stage V tumors with hilar extension underwent longitudinal partial nephrectomy and were evaluated concerning surgical, functional and oncological outcome. The surgical technicque included vascular exclusion and extrarenal cooling during the parenchymal phase of resection. Transsection of the kidney and tumor resection were performed longitudinally. Extensive pyelon reconstruction was carried out, drainage was realized using double J- or transrenal stents. Results Mean age of the five children was 33.5 months (13.5-53), tumor diameter was mean 4.4 cm (1-7), and mean operation time was 200 minutes (129-291). Mean vascular exclusion time was 14 minutes (0-30), an R0 resection was achieved in all cases. Complications consisted of bilateral urinoma in 2 patients. Mean hospital stay was 18.6 days (10-27). Preoperative serum creatinine (mean 0.33, 0.3-0.4) was equal to postoperative values (0.33, 0.2-0.5). MAG3 renal scan revealed equal overall and partial renal function in all cases after surgery compared to preoperative values. All patients are without evidence of disease after a mean follow up of 26.6 months (3.5-66). Conclusions Longitudinal partial nephrectomy for stage V nephroblastoma with hilar extension represents a surgical challenge, but is however justified considering the achievable results. The procedure is associated with an acceptable morbidity and provides excellent functional outcomes.

Robotic Distal Ureterectomy with Boari Flap Reconstruction for Distal Ureteral Urothelial Cancers: A Single Institutional Pilot Experience

Low-grade urothelial tumors of the distal ureter historically can be managed by open distal ureterectomy and ureteral reimplantation with or without bladder reconstruction. In recent years, the da Vinci surgical robotic system (DSRS) (Intuitive Surgical Inc., Sunnyvale, CA) has being increasingly used to perform complex urologic cancer surgeries. In this article, we report first on two consecutive patients undergoing robotic distal ureterectomy and Boari flap reconstruction (RDUBF) for distal ureteral cancer. Two consecutive patients underwent RDUBF, both with a diagnosis of low-grade papillary neoplasm of a distal ureter at our institution between August 2008 and November 2008. Perioperative parameters were prospectively collected and analyzed following institutional review board approval. Two patients, male and female (age, 70 and 71 years, respectively) were included in the study. In both the patients, RDUBF was completed transperitoneally without the need for open conversion. The operative time, estimated blood loss, time to hospital discharge, and time to stent removal for both patients were 270 and 220 minutes, 25 and 35 mL, and 2 days and 6 weeks, respectively. The percentage change in hematocrit following surgery was within 5% in all patients. There were no postoperative complications in both patients. Final pathology demonstrated low-grade carcinoma pT1NxMx and pTaNxMx papillary urothelial carcinoma with negative margins in both patients. A MAG3 (mercapto-acetyl-tri-glycine) renal scan at 3 months demonstrated prompt drainage in both patients. At a median follow-up of 6 months, the patients were alive with no signs of recurrent or metastatic disease on cystoscopic, cytologic, or radiologic follow-up. RDUBF reconstruction is technically feasible with using DSRS in select patients with distal ureteral cancer without disease recurrence in the short term. A larger cohort, with long-term follow-up, is necessary to validate our results.

UPJ obstruction and lower pole crossing vessels: further experience with the laparoscopic vascular hitch

Purpose The transposition of lower pole crossing vessels has been reported as an alternative technique to dismembered pyeloplasty for the treatment of ureterovascular ureteropelvic junction (UPJ) obstruction. We report a multi-institutional experience with laparoscopic transposition in children with intermediate follow-up. Material and Methods Candidate patients were selected on the basis of clinical history, renal ultrasonography, MAG-3 renal scan, and magnetic-resonance angiography. Selection criteria included presence lower-pole crossing vessels with moderate hydronephrosis, poor renal drainage, and intraoperative normal ureter with UPJ peristalsis. All children were followed clinically with renal ultrasonography and postoperative MAG-3 renal scan. Success was defined by symptoms resolution with improvement in hydronephrosis and drainage. Results 36 children (21 boys- 15 girls) presenting with flank pain, hydronephrosis SFU grade 1 or 2, impaired drainage on MAG-3 and crossing vessels at a mean age of 11.5 years (range 3.5-16) were selected. Operations were performed through transperitoneal laparoscopy (n = 33) or robotic assisted (n = 3). The mean operative time was 95 min. (47-137), and length of hospital stay was 2 nights (1-3). With a follow-up of 20 months (3-42), outcome was successful in 34/36 patients (94%), with resolution of symptoms in all, improved hydronephrosis and better drainage. There were 2 failures in children showing recurrent pain and worsened hydronephrosis, who initially required ureteral stent placement. One boy had intrinsic UPJ stenosis and was treated by dismembered pyeloplasty. In the remaining child, adhesions around the renal pelvis had caused kinking of the proximal ureter and extrinsic UPJ obstruction, and subsequently underwent Mikulitz UPJ incision and plasty. Conclusions At intermediate follow-up, the laparoscopic vascular hitch procedure has been successful in treating a selected group of children with obstructive crossing vessels, and represents a safe and reliable alternative to standard dismembered pyeloplasty.

LAPAROSCOPIC PYELOLITHOTOMY IN A PELVIC KIDNEY

orientation of the renal pelvises and the location of the calculus often prevents percutaneous access. However, we show that by keeping a few key principles in mind, laparoscopic surgical success can be achieved in such situations. METHODS: We performed a left laparoscopic pyelolithotomy in a 33 year old woman with a 5cm staghorn calculus. The patient had no evidence of ureteral pelvic junction (UPJ) obstruction on mag-3 renal scan. A retrograde was performed and a 7 fr. double J stent was placed prior to the procedure. Port placement was performed with 4 ports placed in a diamond shape below the umbilicus. The ureter and renal pelvis

Endoscopic treatment of vesicoureteral reflux in the previously reimplanted ureter: technical aspects and results

To assess the feasibility and results of the endoscopic treatment of vesicoureteral reflux (VUR) after a failed ureteral reimplantation. From January 1996 to October 2006, 28 patients underwent endoscopic treatment for VUR grade II to V persisting after open ureteral reimplantation. VUR was bilateral in 11 patients, for a total of 39 ureteral units (UU) treated. The endoscopic treatment was performed 1 to 7 years after surgery (average 2.5 years). Dextranomer/Hyaluronic acid Copolymer (Dx/HA) was used as injectable material. The amount of injected material ranged from 0.5 to 2.8 ml (average: 1.2 ml). Some technical refinements were required to increase the success of the procedures. Patients were followed up from 2.5 to 17 years. Voiding cystourethrogram (VCUG) was performed at 6 months and MAG3 renal scan with voiding phase at 24 months. Results were compared with the outcome of the endoscopic treatment in patients treated by the same surgeons for primary VUR, matched for grade (control group). All treatments were performed as one-day procedure. No complications were observed. Success was achieved in 22/28 patients (78.5%) and in 30/39 UU (76.9%) after failed ureteral reimplantation. No significant difference in success rate was found from the control group (p = ns). Endoscopic treatment of VUR after a failed reimplantation can be a challenging procedure, for a skilled endoscopists. Nonetheless it can achieve successful results in a high percentage of patients with minimal morbidity and a minimal invasiveness; it should thus be recommended for these patients.

Monitoring Renal Function: A Prospective Study Comparing Camera-Based Technetium-99m Mercaptoacetyltriglycine Clearance and Creatinine Clearance

To determine the value and limitations of technetium-99m mercaptoacetyltriglycine (MAG3) clearance measurements obtained using a gamma camera (camera-based MAG3 clearance), a prospective study was conducted to evaluate the reproducibility of camera-based MAG3 clearance compared with that of conventional creatinine clearance. A total of 24 male patients with stable renal function were entered into the study. The mean age was 66.5 +/- 7.9 years, and the mean serum creatinine was 1.38 +/- 0.57 mg/dL. MAG3 renal scans and 24-hour creatinine clearance measurements were performed 11 +/- 8 days apart. A camera-based MAG3 clearance was obtained at each MAG3 scan; no blood samples were required. Bland-Altman plots were constructed to assist in data analysis. The Pearson correlation for the first and second camera-based MAG3 clearances (mean 151 versus 158 mL/min/1.73 m2, respectively) was 0.965 compared with 0.729 for the two creatinine clearance measurements (mean 62 versus 72 mL/min/1.73 m2, respectively). Even with the omission of two outliers, the creatinine clearance would have to change by 58.2% compared with the baseline measurement before the clinician could be confident the change exceeded the error of measurement. In contrast, the change required for the camera-based MAG3 clearance was 30.8%. The results of this study have demonstrated that MAG3 clearance obtained using a camera-based technique shows greater precision than the conventional creatinine clearance and is superior to the conventional creatinine clearance for monitoring changes in renal function.

Robotic dismembered pyeloplasty for the treatment of ureteropelvic junction obstruction.

Objective: Laparoscopic pyeloplasty has been shown to have equivalent surgical outcomes with less surgical morbidity when compared to the open approach. The laparoscopic approach has traditionally been performed in a few specialized training centers because of the advanced technical skills required to perform this complex reconstructive procedure. The introduction of robotic technology into the modern day operating suite has brought on a new era and has simplified complex urologic reconstructive procedures. The daVinci robot provides the advantages of three-dimensional vision, magnification, and a robotic articulating wrist. These features allow precise dissection and suturing capabilities. We used the daVinci robot to perform robotic assisted laparoscopic pyeloplasty. We studied its feasibility, utility, and efficacy. Methods: Between July 2002 and April 2003, 12 patients with a mean age of 29.2 years (16-56) underwent robotic assisted laparoscopic dismembered pyeloplasty. Each patient had presented with flank pain (six left and right) and had been diagnosed with a ureteropelvic junction (UPJ) obstruction by either IVP or MAG3 renal scan. A retrograde pyelogram was performed preoperatively to delineate the anatomy and a stent was placed. Robotic dismembered pyeloplasty was performed. Eight of 12 patients had crossing vessels only five of which were shown on preoperative CT scan. The crossing vessels were preserved in all cases. The UPJ was dismembered at the point of obstruction and the scar excised. The ureter was spatulated medially and the renal pelvis fashioned appropriately. Ureteropelvic reconstruction was performed with eight-interrupted 4-0 monocryl sutures on an RB-1 needle in the first five cases. In the other seven cases the anastomosis was performed with two running semicircular sutures. Stents were removed at 14-28 days. An IVP was performed prior to stent removal and a renal scan at 3 and 6 months. Results: Each patient underwent a successful procedure without open conversion, transfusion or complication. Estimated blood loss was minimal at 52 cm3. Each patient was discharged home on the first postoperative day, average 18 h. Operative times fell quickly as experience with the daVinci robot increased. Operative time averaged 201 min. The first five patient's average or time was 262 vs. 158 min for the last seven. Time for the anastomosis averaged 42 min (100-20). The initial five cases were performed with an interrupted anastomosis. These took longer averaging 65.4 min (100-33). The subsequent seven cases were performed with two running hemi-circumferential stitches with anastomotic time averaging 25 min (30-20). Intraoperatively no complications were noted. Postoperatively the average hospital stay measured from the time of surgery to the time of discharge averaged 18 h (24-16). No postoperative complications have been noted. Average return to work is 10.9 days, and clearance for full activity at 17 days. Duration of the stent has averaged 18 days (24-13). The initial five patients with the interrupted anastomosis had longer stent times of 22.2 days (28-17) while the patients with a running anastomosis has average stent times of 17.6 days (22-13). Average follow up is currently 4.9 months (2-10). Each patient is doing well with no signs of recurrent obstruction. Follow up has been documented with MAG3 renal scan with Lasix at 3, 6 and 9 months. Conclusion: The adoption of robotic technology into today's modern operating rooms has stimulated a new era in urologic surgery. The daVinci robot provides magnified three-dimensional vision and a miniature robotic articulating wrist that allows precise dissection and laparoscopic suturing. Robotic dismembered pyeloplasty is an excellent technique with very good results. As experience with the robotic instrumentation increases operative times fall quickly. Blood loss and pain are minimal, allowing early discharge home and quick recovery. The short-term results are promising. Longer follow-up is needed.

Supernumerary Left Kidney

A 77-year-old woman with a history of right breast cancer and recently diagnosed B-cell lymphoma was evaluated for developing renal insufficiency with ultrasound and a Tc-99m MAG3 renal scan. These studies demonstrated the presence of 3 functioning native kidneys. Supernumerary kidneys are a very rare congenital anomaly, and the use of renal scintigraphy plays an important role in both the diagnosis and the evaluation of renal function in such patients.

Non-Invasive Contrast Enhanced Electron Beam Tomography: A Three Dimension Imaging Adjunctive Test To Detect Renal Vascular and A-V Fistula Graft Abnormalities.

Electron beam tomography (EBCT) is a relatively new technology with several potential advantages over traditional CT such as fast acquisition time, less exposure to radiation, less sedation and volume of dye, and better 3D visualization. A retrospective study was done to assess the use of 3D EBCT to detect renal vascular abnormalities and patency of arteriovenous-fistula (A-VF) and arteriovenous-graft (A-VG). EBCT was done in 7 children (age 3–18 year, mean age 10.8 years). All had hypertension (> 95%) and high rennin levels. Four of the patients (group I) had normal renal function. One patient (group II) was 20 days post enblock renal transplantation with ascites, hypertension and renal dysfunction. Two patients (group III) had end-stage renal disease, hypertension, and AV-F and AV-G. One of these patients had SLE and difficult IV access. In group I, 2/4 had left ventricular hypertrophy, eye and CNS changes. MAG-3 renal scan (RSC) and renal ultrasound (RUS) were normal in 2/4 group I patients. In group I, 2/4 EBCT showed unilateral renal artery stenosis: one of these children had decreased velocity in one kidney by RUS and the other child had possible renal artery stenosis by RSC. One child in group I with abnormal RUS suggestive of RAS did not have RAS by EBCT and traditional angiography. In group II, patient with transplant, EBCT showed normal renal vasculature and ureterovesicle anastomoses without RAS or leak respectively. In group III, the SLE patient had thrombosis of the inferior vena cava and renal veins and the other patient had patent A-VF with dilated vessels contrary to US finding of thrombosis. In conclusion, EBCT with its non invasive, maximum intensity projection and 3D images, less radiation and acquisition time is a useful adjunct test to detect RAS and AV-F, AV-G and transplant vascular thrombosis/stenosis in children.

Salvage of compromised renal vessels in kidney transplantation using third-party cadaveric extenders: impact on posttransplant anti-HLA antibody formation.

Kidney transplant surgery can be complicated by short, attenuated, or injured renal vessels which are now more frequently encountered with laparoscopic right donor nephrectomy. We describe a technique to overcome this problem in seven recipients (2 cadaveric and 5 living donors) by constructing third-party "vascular extenders" using cadaveric iliac vessels retrieved previously and preserved at 4 degrees C in University of Wisconsin solution. Mean vessel cold storage time was 25.7 days (range, 2-56 days). Immunosuppression consisted of sirolimus, mycophenolate mofetil, and steroids. Prompt reperfusion of all allografts was observed, and there were no surgical complications. Integrity of the extenders was confirmed using serial MAG3 renal scans and magnetic resonance angiography. Mean serum creatinine was 1.44 mg/dl at 19.2 months (range, 0.7-2 mg/dl at 3-31 months). Each recipient had a negative posttransplant kidney donor specific flow cytometry crossmatch. Two recipients developed HLA antibodies, one to DR7 and another DR13 (mismatched to the vessel donor) at 4 and 11 months posttransplant, respectively.

Early repeated exploration after laparoscopic urologic surgery: comparison of clinical, radiologic, and surgical findings

Objectives. To correlate the clinical scenarios and radiographic findings with the operative findings in patients who underwent repeated exploration to define a management strategy. Postoperative complications after laparoscopy may cause diagnostic challenges because of atypical presentation. Methods. We retrospectively reviewed the records from 1226 urologic laparoscopic procedures between July 1993 and July 2000. We compared the clinical, radiologic, and surgical findings of patients who underwent repeated exploration within the first month after laparoscopy. Results. During the study period, 9 patients (0.7%) were taken back to the operating room for repeated exploration. The median time for the appearance of symptoms was the second postoperative day. Eight patients were evaluated by computed tomography (CT) and one by both renal Doppler ultrasonography and MAG-3 renal perfusion scan. Repeated operations were laparoscopic in 4 and open in 5 patients. In all the patients evaluated by CT scan, the radiologic findings were consistent with the surgical findings. In the patients who underwent diagnostic laparoscopy because of the severity of clinical findings, despite negative CT findings, no abnormality was discovered at exploration. In 1 patient who was not evaluated by CT, duodenal perforation was detected at exploration. Conclusions. Clinical findings may not be sufficient for the decision of repeated operation for patients acutely ill after laparoscopy. CT findings correlated well with the findings at exploration. In cases in which no abnormality is detected by CT, it appears reasonable to withhold surgical exploration unless the clinical situation deteriorates.

ELECTRON BEAM COMPUTERIZED TOMOGRAPHY ASSESSMENT OF IN VIVO SINGLE KIDNEY GLOMERULAR FILTRATION RATE AND TUBULAR DYNAMICS DURING CHRONIC PARTIAL UNILATERAL URETERAL OBSTRUCTION IN THE PIG

The assessment of hydronephrosis due to chronic partial ureteral obstruction is controversial. We determined whether a new radiographic technique for assessing kidney function, electron beam computerized tomography (CT), can detect altered renal physiology due to chronic partial ureteral obstruction. We also compared and contrasted electron beam CT with standard well tempered diuretic mercaptoacetyltriglycine (MAG-3) urography. MATERIALS ANDS METHODS: Six pigs underwent creation of unilateral partial ureteral occlusion or sham operation. Three weeks after surgery diuretic enhanced MAG-3 renal scan was done and 48 hours later contrast enhanced electron beam CT was performed. Mean differential function plus or minus standard error of mean of the obstructed kidney was 5.6% +/- 2.4% on MAG-3 renography. In contrast, electron beam CT revealed significantly preserved mean renal function at 24.5% +/- 2.7% (p <0.01). Electron beam CT analysis of tubular function revealed persistent glomerular filtration and filtrate flow through the proximal tubules and loop of Henle with a selective decrease in distal tubular flow, which were findings suggestive of proximal tubular sparing that were not demonstrated by nuclear renography. Renal function on MAG-3 renography is primarily determined by measuring kidney perfusion and tubular secretion of the isotope. In contrast, electron beam CT determines renal function via quantifying the in vivo single kidney glomerular filtration rate and by assessing renal tubular function. This study documents that electron beam CT of differential renal function is significantly different from that of MAG-3 renography. To our knowledge which of these 2 radiographic studies is most clinically applicable is unknown to date.

¿es necesario efectuar un renograma isotópico diurético en las dilataciones pielocaliciales grado ii ecográfico?

PurposeThe increasing number of ultrasonographically detected asymtomatic, renal dilations have caused a lot of explorations to be performed in these patients. The Society of Fetal Urology proposed a four grades classification of echographic renal dilations and renographic studies are recommended in grades II to IV. However we have observed that grade II dilations don’t evolve to obstruction. The aim of this work is to evaluate the obstruction rate in this group of patients, and the necessity or not of practising diuretic renography Material and methodWe studied 42 children diagnosed of grade II renal dilation during a 1,5 year period. Left side was more frequently affected, 23 cases, 7 cases were bilateral what means 49 affected renal units. There was a male predominance (69%). Mean age at diagnosis was 2 months (0 to 36 months). Seventy nine per cent were prenatally diagnosed ResultsThe MAG-3 renal scan showed 48 unobstructed renal units and 1 obstructed. The F-15 variant was made in 15 cases by a doubtful curve or retarded elimination. The patient with obstructive curve presented an 15 mm renal pelvic diameter echographically measured and the intravenous urography showed a higher dilation being operating on. The mean time follow up was 23,5 months (13 to 53 months) without any change ConclusionGrade II pielocalicial dilations with renal pelvis lesser than 15 mm can be echograpically controlled without renal scan. It should be performed only if renal dilation increases