Injury to a transplanted kidney during caesarean section: a case report.
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As fertility is restored after renal transplant, more female recipients of a renal transplant successfully complete pregnancies that are safe for the mother, the fetus, and the renal allograft. Although the transplanted kidney lies in one of the iliac fossae, normal vaginal delivery is not impeded by this positioning. Caesarean section is indicated in many scenarios, primarily for obstetric reasons, particularly when the transplanted kidney lies in a position where it could be injured. Here, we report our experiences managing a rare instance of injury to a transplanted kidney during caesarean section and discuss the relevant aspects of its management. To our knowledge, this is the first report in the English literature of an injury to a transplanted kidney during caesarean section. (+info)
BACKGROUND AND OBJECTIVES: Pyeloplasty, whether open or laparoscopic, has been the mainstay of treatment for ureteropelvic junction obstruction (UPJO). A nonstented pyeloplasty has only been reported in the pediatric literature. Herein, to the best of our knowledge, we report the first published experience with laparoscopic stentless pyeloplasty (LSP) in the adult population. METHODS: Patients with a normal contralateral kidney who underwent a laparoscopic pyeloplasty were included in this study. A dismembered pyeloplasty was performed without the placement of a ureteral stent. Functional Tc-99m MAG3 renal-scan data were compared with results at 4 weeks and 6 months postoperatively. Perioperative complications and long-term follow-up were prospectively gathered. RESULTS: To date, 5 patients have undergone LSP with a mean follow-up of 15.7 months. Mean age and body mass index of this group were 42.8 years and 29.3 kg/m(2), respectively. Mean operative time, estimated blood loss, and hospital stay were 196 minutes, 58 mL, 1.6 days, respectively. Three patients had right-sided UPJO, and 2 patients had left UPJO. No patient had undergone previous surgery for UPJO. All patients had a ureteral stent in place at the time of surgery. No intraoperative complications occurred. Only one patient complained of flank pain on POD1. No obstruction or urinary extravasation was seen on retrograde pyelography, but a ureteral stent was placed. During our follow-up, all patients had complete resolution of their symptoms. Postoperative renal scans demonstrated improved urinary drainage in all patients. CONCLUSION: Our initial experience suggests that in experienced hands, LSP may be an effective method for treating UPJO. (+info)
Optimal scintigraphic evaluation of a hydronephrotic horseshoe kidney.
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A 25-y-old man with horseshoe kidney was referred for diuretic-augmented renal scintigraphy. Single-detector dynamic posterior imaging was performed and revealed asymmetric retention of radiotracer in the left collecting system. Renal scintigraphy was repeated with a modified protocol. Dynamic imaging was performed this time using dual-detector acquisition of both anterior and posterior data. Thereafter, pregravity and subsequently postgravity static images were obtained in both anterior and posterior projections. This second study showed near-complete emptying of the left collecting system. This case illustrates the utility of using simultaneous anterior and posterior imaging and geometric mean calculations for functional analysis and also highlights the value of physiologic maneuvers to augment the traditional diuretic challenge. (+info)
Decision support systems in diuresis renography.
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The volume of diagnostic imaging studies performed in the United States is rapidly increasing resulting from an increase in the number of patients as well as an increase in the volume of studies per patient. Concurrently, the number and complexity of images in each patient data set are also increasing. Nuclear medicine physicians and radiologists are required to master an ever-expanding knowledge base whereas the hours available to master this knowledge base and apply it to specific tasks are steadily shrinking. The convergence of an expanding knowledge base and escalating time constraints increases the likelihood of physician errors. The problem is particularly acute for low-volume studies such as MAG3 diuresis renography where many imagers may have had limited training or experience. To address this problem, renal decision support systems (DSS) are being developed to assist physicians evaluate suspected obstruction in patients referred for diuresis renography. Categories of DSS include neural networks, case-based reasoning, expert systems and statistical systems; RENEX and CART are examples of renal DSS currently in development. RENEX (renal expert) uses a set of rules obtained from human experts to analyze a knowledge base of expanded quantitative parameters obtained from diuresis MAG3 scintigraphy whereas CART (classification and regression tree analysis) is a statistical method that grows and prunes a decision tree based on an analysis of these quantitative parameters in a training data set. RENEX can be queried to provide the reasons for its conclusions. Initial data show that the interpretations provided by RENEX and CART are comparable to the interpretations of a panel of experts blinded to clinical information. This project should serve as a benchmark for the scientific comparison and collaboration of these 2 fields of medical decision-making. Moreover, we anticipate that these DSS will better define the essential interpretative criteria, foster standardized interpretation, teach trainees to better interpret renal scans, enhance diagnostic accuracy and provide a methodology applicable to other diagnostic problems in radiology and medicine. (+info)
Diagnostic performance of an expert system for interpretation of 99mTc MAG3 scans in suspected renal obstruction.
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Functional assessment of the kidney from magnetic resonance and computed tomography renography: impulse retention approach to a multicompartment model.
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Estimation of technetium-99m-MAG3 renal clearance in children: two gamma camera techniques compared with multiple plasma samples.
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Dynamic renal scintigraphy using technetium-99m mercaptoacetylglycylglycylglycine (MAG3) has been described in adults, and clearance values have been established using multiple plasma samples. This study of renal clearance has compared two fundamentally different gamma camera techniques (both of which require a single blood sample) with the multiple blood sampling technique in children (n = 30). Results show that a 40-min dynamic 99mTc-MAG3 renal scintigram coupled with a single plasma sample will allow analysis of the data so that clearance values, which are similar to those from multiple plasma samples, may be calculated. The curve generated from the cardiac region of interest (ROI) provided clearances values that had a high correlation coefficient (0.939-0.951) compared to the multiple-plasma sample technique immaterial of the timing of the blood sample. The renal uptake method of clearance had a lower correlation coefficient (0.89-0.92), which varied with the timing of the blood sample compared to the multiple-plasma sampling technique. This study has demonstrated that an extended gamma camera acquisition coupled with a single-plasma sample may be used for quantitative renal function studies using 99mTc-MAG3. (+info)
Technetium-99m-MAG3 versus iodine-123-OIH: renal clearance and distribution volume as measured by a constant infusion technique.
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The renal clearance and distribution volume of 99Tc-mercaptoacetyltriglycine (MAG3) and 123I-o-iodohippurate (OIH) were determined separately in six normal male volunteers using the constant infusion clearance technique in order to validate single injection clearance techniques and subsequently the normal values for these parameters. MAG3 renal clearance was 257 +/- 24 ml/min/1.73 m2, compared to the OIH clearance of 556 +/- 46 ml/min/1.73 m2 resulting in a MAG3/OIH clearance ratio of 0.47 +/- 0.06. The MAG3 and OIH apparent distribution volumes at steady-state were 14.8 +/- 3.7 and 19.4 +/- 5.3 liters, respectively, the latter value approximating the extra cellular fluid volume. Urinary excretion in the 0-30-min period after intravenous administration was 64.4 and 70.2% for MAG3 and OIH, respectively. This investigation revealed some significant differences in the normal values of the renal clearance and distribution volume of MAG3 compared with other studies. (+info)