Use of percutaneous nephrostomy in hydronephrosis of pregnancy

A novel method for estimating the urine drainage time from the renal collecting system

PURPOSE

Partial obstruction of the upper urinary tract is a common urological pathology that leads to progressive atrophy and dysfunction of the kidney. Most methods for evaluating the urine drainage rate, to assess the severity of partial obstruction, involve injection of markers into the blood stream and therefore the filtration rate from the blood effects the drainage rate. This study presents a novel method for assessing the drainage rate from the upper urinary tract by analyzing sequential fluoroscopic images from a routine nephrostogram, in which contrast material is introduced directly into the renal collecting system.

METHODS

Fluoroscopic images from 36 nephrostograms, following percutaneous nephrolithotomy, were retrospectively evaluated, 19 with a dilated renal pelvis. A radiological model for calculating the radiopacity of the renal pelvis, which reflects the amount of contrast material in each sequential image, was developed. Using this model, an algorithm was designed for generating a drainage curve and calculating the "drainage time" t_1/2 in which half of the contrast material has drained from the renal pelvis.

RESULTS

Analysis of images of a step-wedge phantom made of an increasing number of contrast material layers showed that the calculated radiopacity of each step was proportional to the amount of contrast material, independent of the background attenuation. Analysis of the nephrostograms showed that the drainage curves highly fitted an exponential function (R = 0.961), with a significantly higher t_1/2 for dilated cases.

CONCLUSION

The developed method may be used for a quantitative and accurate estimation of the urine drainage rate.

ACR Appropriateness Criteria® Radiologic Management of Urinary Tract Obstruction

Acute obstructive uropathy is a medical emergency, which often is accompanied by acute renal failure or sepsis. Treatment options to resolve the acute obstructive process include conservative medical management, retrograde ureteral stenting, or placement of percutaneous nephrostomy or nephroureteral catheters. It is important to understand the various treatment options in differing clinical scenarios in order to guide appropriate consultation. Prompt attention to the underlying obstructive process is often imperative to avoid further deterioration of the patient's clinical status. A summary of the data and most up-to-date clinical trials regarding treatment options for urinary tract obstruction is outlined in this publication. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Percutaneous nephrostomy placement in pregnant patients: a retrospective single center experience

Purpose: Literature on percutaneous nephrostomy (PCN) placement in pregnant patients is limited. The purpose of this case series of 20 pregnant patients was to report short term maternal and fetal outcomes in this population.Materials and methods: A 12-year retrospective study was performed on pregnant patients undergoing PCN. Clinical indications, technical success, maternal outcome, fetal outcome, and complications were obtained from the electronic medical record.Results: Indications for PCN placement included urolithiasis (40%), congenital ureteral dysfunction in the setting of prior ureteral repair (30%), obstruction associated pain (15%), infection (10%), and ureteral injury in the setting of surgery for ovarian torsion (5%). Catheter insertion was successful in all patients (n = 20), with one major complication (urosepsis). Follow up data was available in 19 patients (95%). Catheters were in situ for a median of 82 days. All patients had clinical and symptomatic improvement. Emergency C-sections were required in two cases. Radiation exposure data were available in 15 of 19 patients and revealed a median fluoroscopy time of 2.8 min, median cumulative dose of 43 mGy, and median dose area product of 635 µGy × m². No adverse fetal outcomes were recorded at time of delivery.Conclusion: PCN placement has good clinical results as a treatment option for ureteral obstruction in a pregnant cohort.

Invasive management of proximal ureteral calculi during pregnancy

OBJECTIVE

To review our experience with invasive management of proximal ureteral calculi during pregnancy when conservative treatment fails.

METHODS

From February 2006 to September 2012, a total of 87 pregnant women received invasive management for proximal ureteral calculi in our center. Invasive management included the following: double-J stent insertion, percutaneous nephrostomy (PCN), and ureteroscopic lithotripsy (URSL). The medical records of these patients were reviewed retrospectively.

RESULTS

Of the 87 patients, 4 patients received PCN; 19 patients received cystoscopic double-J stent insertion, whereas 2 patients (10.5%) failed in guide wire inserting and switched to ureteroscopic aid; a total of 64 patients received URSL with holmium laser, in which 52 patients (81.2%) had complete fragmentation of calculi; in 9 patients (14.1%), stone fragments retrograde migrated to the renal pelvis; in 3 patients (4.7%), the stone could not be reached because of serious ureteral tortuosity. One patient (1.6%) patient had a threatened abortion, but this problem was resolved immediately using conservative treatment. All patients completed the full term of pregnancy, and no serious obstetric or urologic complications were observed.

CONCLUSION

For pregnant patients with proximal ureteral calculi, double-J stent insertion, PCN, and URSL all are effective and safe options when conservative treatment fails. They should be chosen on the basis of different patient's condition. However, patient's postoperative tolerance was poor for double-J stent insertion and PCN; URSL (especially with holmium laser lithotripsy) is more effective and should be considered as the preferred choice.

The evaluation of ureteroscopy and pneumatic lithotripsy results in pregnant women with urethral calculi

Background

Urinary stone incidence in pregnancy has been reported in a wide range, from 1 in 200 to 1 in 2000 cases.

Objectives

The aim of this study was to investigate the efficacy and safety of ureteroscopic treatment and its results and complications for pregnant women with urinary stones.

Patients and Methods

From 2003 till 2011, 113 pregnant patients with symptomatic urolithiasis were admitted to the urology emergency clinic at Imam Reza hospital. All patients were initially treated conservatively, resulting in spontaneous passage of the calculi in 69 patients. Forty-four patients with symptomatic urolithiasis were included in the study. Post-operative follow ups, including maternal and fetal health was performed by a gynecologist consult fetal heart rate assessment and urine analysis and culture and renal and urethral ultrasonography.

Results

The mean age of the patients was 23 years ± 2 (19-34) and the mean gestational age was 24 ± 3 weeks. The overall and pneumatic lithotripsy success rate was 100%. All patients from the interventional group delivered at term with no fetal or maternal complications. There was no morbidity during and after the operation.

Conclusions

In conditions, medical management of urinary stones and consequent renal colic in pregnant women cannot improve patients’ symptoms, choosing of a surgical method like setting of a DJ catheter or URS and pneumatic lithotripsy can be a safe and effective way for the health of both the mother and fetus. Of course, more research is needed to establish this approach as the standard method in pregnancy urinary stones.

Success and Short-term Complication Rates of Percutaneous Nephrostomy during Pregnancy

Outcome of percutaneous nephrostomy creation during pregnancy was retrospectively studied. Catheter insertion was successful in all cases (N = 8; 3% of all nephrostomies over a 5-year period), with one major complication (sepsis) and three minor complications. Catheters remained in situ for a mean of 9.4 days until the stone passed (n = 1) or was removed on ureteroscopy (n = 2) or a ureteral stent was inserted (n = 5). Maternal outcome was normal in all cases, but there were two premature deliveries. Nephrostomy during pregnancy has acceptable technical and clinical results, but the possibility of an increased risk of septic complications (12.5% in this series) necessitates further study.

Blind percutaneous renal access

We describe a technique of blind percutaneous renal access when retrograde/intravenous imaging is not possible. We present the surgical technique, the patient population, and situations in which the technique is used. Following a review of 40 accesses, we concluded that this technique is safe, simple, and effective. It also allows the urologist to act autonomously in obtaining renal access.