Percutaneous nephrostomy of nondilated renal collecting systems with fluoroscopic guidance: technique and results

Ultrasound contrast agent assisted ultrasonography guidance percutaneous nephrostomy for non-hydronephrotic kidney

BACKGROUND

Given the limited success rate and considerable challenges associated with conventional ultrasonography (US) guidance for percutaneous nephrostomy (PCN) in non-hydronephrotic kidneys, this study proposed a solution with ultrasound contrast agent to enhance the success rate and mitigate the difficulties.

MATERIALS AND METHODS

From January 2017 to August 2023, a total of thirteen patients diagnosed with non-hydronephrotic kidney were included in the study. Following routine ultrasonography examination, no significant dilatation of the renal collecting system was observed. US-guided percutaneous nephrostomy PCN was performed with the assistance of ultrasound contrast agent (UCA). The patients were subsequently monitored to assess the improvement of symptoms and postoperative recovery.

RESULTS

The success rate was found to be 100% for all patients (13/13) and kidneys (20/20). The average volume of UCA solution used was 19 ± 6.7 mL (range, 11-35 mL), while the mean duration of the operation was 18.92 ± 8.96 min (range, 7-36 min). A majority of the patients (12/13) underwent a single puncture procedure. Throughout the follow-up period, no serious complications were observed, and surgery resulted in significant alleviation of symptoms in all patients.

CONCLUSION

The use of UCA-assisted US guidance PCN has been shown to be effective in achieving urinary diversion and alleviating associated clinical symptoms in non-hydronephrotic kidneys. In comparison to traditional methods, this approach demonstrates a high success rate and safety profile, while also offering a simplified operative procedure. Consequently, it presents a novel method and concept for managing non-hydronephrotic kidneys afflicted by urine leakage.

Contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with a non-dilated collecting system: results of a pooled analysis of randomized controlled trials

BACKGROUND

Contrast-enhanced ultrasound in percutaneous nephrolithotomy (CEUS-PCNL) is an economical and practical technique for the treatment of patients with renal stones without significant collecting system dilatation. The aim of this systematic review is to compare the safety and efficacy of CEUS-PCNL and conventional ultrasound (US)-guided (US-PCNL) treatment of patients with renal calculi without significant hydronephrosis.

METHODS

This review was conducted with strict adherence to the PRISMA guidelines. Comparative studies on CEUS-PCNL and US-PCNL published in PubMed, SinoMed, Google Scholar, Embase, and Web of science until March 1, 2023, were systematically searched. RevMan 5.1 software was used for meta-analysis. Pooled odds ratios (ORs), weight mean differences (WMDs) and standard mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using the fixed-effects or random-effects model. Publication bias was evaluated using funnel plots.

RESULTS

Four randomized controlled trials involving 334 patients (168 with CEUS-guided PCNL and 166 with US-guided PCNL) were identified. There was no statistically significant difference between CEUS-guided PCNL and US-guided PCNL in terms of the operation time (SMD: - 0.14; 95% CI - 0.35 to 0.08; p = 0.21), minor complications (p = 0.48), major complications (p = 0.28) and overall complications (p = 0.25). However, CEUS-guided PCNL had a higher stone-free rate (OR: 2.22; 95% CI 1.2 to 4.12; p = 0.01), higher success rate of single-needle punctures (OR:3.29; 95% CI 1.82 to 5.95; p < 0.0001), shorter puncture time (SMD: - 1.35; 95% CI - 1.9 to - 0.79; p < 0.00001), shorter hospital stay (SMD: - 0.34; 95% CI - 0.55 to - 0.12; p = 0.002) and lesser hemoglobin loss (SMD: - 0.83; 95% CI - 1.06 to - 0.61; p < 0.00001) as compared with conventional US-guided PCNL.

CONCLUSIONS

According to almost all pooled data, CEUS-guided PCNL is superior to US-guided PCNL in terms of the perioperative outcomes. However, many rigorous clinical randomized controlled studies are required to obtain more accurate results. Registration The study protocol was registered with PROSPERO (CRD42022367060).

The safety and efficacy of ultrasound versus fluoroscopic percutaneous nephrostomy: A prospective randomized study

Objective

The objective of this study is to compare the outcome of percutaneous nephrostomy by ultrasound (US) versus fluoroscopy including access time, volume of anesthesia required, success rate, and complications.

Methods

One hundred patients were enrolled in a prospective randomized study. Patients were divided into two groups, 50 cases each. Comparing the two groups was done regarding the need for dye, radiation effect, time taken, trial number, rate of complication, volume of anesthesia, and success rate.

Results

Patient demographics were comparable between both groups with no statistically significant difference. According to the modified Clavien-Dindo classification, the complications were Grade I (pain and mild hematuria) in each group. Procedural pain was present in 41 (82%) patients in Group I and in 48 (96%) patients in Group II. It was treated in both groups with a simple analgesic. Mild hematuria was present in 5 (10%) patients in the US group and 13 (26%) in the fluoroscopic group and treated by hemostatic drugs only. There was a statistically significant difference between both groups regarding the volume of required local anesthesia, the trial numbers, the puncture numbers, bleeding, extravasation, and change in the hemoglobin level.

Conclusion

US percutaneous renal access is a safe and effective modality with a high success rate, less operative time, and complication rate. However, a minimum of 50 cases with some pelvicalyceal system dilation may be preliminary requisites to achieve good orientation and competence in achieving safe US percutaneous renal access for future endourological procedures.

Comparison of Contrast-Enhanced Ultrasound vs Conventional Ultrasound-Guided Percutaneous Nephrolithotomy in Nondilated Collecting System: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: It has been demonstrated that ultrasound (US)-guided renal collecting system access during percutaneous nephrolithotomy (PCNL) is efficient and secure. The puncture success rate fell to 82%, and the total complication rate rose to 15% in kidneys with nondilated collecting systems. Contrast-enhanced ultrasonography (CEUS) has been used in PCNL techniques to address this issue. Methods: We did this meta-analysis following the preferred reporting criteria for systematic reviews and meta-analysis to combine the data of published studies to compare the CEUS-guided PCNL and the standard US-guided PCNL (PRISMA). For relevant literature, we searched PubMed, Embase, Web of Science, CKNI, and the Cochrane Library. The final inclusion date for this meta-analysis was May 1, 2022, and three randomized controlled trials (RCTs) were finally included. RevMan V5.4.1 was used in this work. Standard mean difference (SMD) with a 95% confidence interval (CI) was utilized as the major estimate in the synthesis of continuous data, while odds ratio (OR) with a 95% CI was synthesized as the main estimate in the synthesis of discontinuous data. Results: We found that compared with traditional US-guided PCNL, CEUS-guided PCNL could offer more benefits in terms of single-needle success rate (OR: 3.02, 95% CI: 1.62 to 5.61, p = 0.0005), shorter puncture time (SMD: -1.33, 95% CI: -2.06 to -0.60, p = 0.0004), shorter hospital stays (SMD: -0.37, 95% CI: -0.60 to -0.13, p = 0.002), and a better stone clearance rate (OR: 2.32, 95% CI: 1.15 to 4.68. p = 0.02). Although the PCNL complication rate after surgery was not significantly reduced by the CEUS technique (overall complication: OR = 0.70, 95% CI: 0.37 to 1.30, p = 0.25. Grade 1/2 complication: OR = 0.79, 95% CI: 0.41 to 1.53, p = 0.48; Grade 3/4 complication: OR = 0.44, 95% CI: 0.10 to 1.98, p = 0.28), it could reduce hemoglobin dropping compared with conventional US-guided PCNL (SMD: -0.82, 95% CI: -1.06 to -0.58, p < 0.001). Conclusion: The CEUS-guided PCNL technique is superior to the US-guided PCNL, according to almost all synthesized data. Additional randomized studies are still required.

Outcomes Related to Percutaneous Nephrostomies (PCN) in Malignancy-Associated Ureteric Obstruction: A Systematic Review of the Literature

Background: Malignant ureteric obstruction occurs in a variety of cancers and has been typically associated with a poor prognosis. Percutaneous nephrostomy (PCN) can potentially help increase patient longevity by establishing urinary drainage and treating renal failure. Our aim was to look at the outcomes of PCN in patients with advanced cancer and the impact on the patients’ lifespan and quality of life. Materials and Methods: A literature review was carried out for articles from 2000 to 2020 on PCN in patients with advanced malignancies, using MEDLINE, EMBASE, Scopus, CINAHL, Cochrane Library, clinicaltrials.gov, and Google Scholar. All English-language articles reporting on a minimum of 20 patients who underwent PCN for malignancy-associated ureteric obstruction were included. Results: A total of 21 articles (1674 patients) met the inclusion criteria with a mean of 60.2 years (range: 21–102 years). PCN was performed for ureteric obstruction secondary to urological malignancies (n = −633, 37.8%), gynaecological malignancies (n = 437, 26.1%), colorectal and GI malignancies (n = 216, 12.9%), and other specified malignancies (n = 205, 12.2%). The reported mean survival times varied from 2 to 8.5 months post PCN insertion, with an average survival time of 5.6 months, which depended on the cancer type, stage, and previous treatment. Conclusions: Patients with advanced malignancies who need PCN tend to have a survival rate under 12 months and spend a large proportion of this time in the hospital. Although the advent of newer chemotherapy and immunotherapy options has changed the landscape of managing advanced cancer, decisions on nephrostomy must be balanced with their survival and quality of life, which must be discussed with the patient.

Assessment of the Contrast-Enhanced Ultrasound in Percutaneous Nephrolithotomy for the Treatment of Patients with Nondilated Collecting System

Purpose: To investigate the clinical value of contrast-enhanced ultrasound (CEUS) in percutaneous nephrolithotomy (PCNL) for kidney stone patients without hydronephrosis. Methods: Patients with nondilated collecting system kidney stones who underwent PCNL between October 2018 and December 2019 at our hospital were enrolled in this study. Patients who met the inclusion criteria were randomized into two groups: a CEUS-guided PCNL group and a conventional ultrasound (US)-guided PCNL group. The operation results of the two groups were compared, including the number of attempts for effective puncture, duration to effective puncture, stone clearance rate, blood loss, postoperative complications, and hospital stay. Results: Fifty-six patients with a nondilated collecting system who underwent PCNL for 60 kidneys were included in this study, including 4 patients who underwent bilateral PCNL due to bilateral renal stones. There were 30 kidneys in each group. All patients successfully underwent PCNL. The CEUS-guided PCNL group had more accurate punctures, with a higher effective rate of one puncture and shorter puncture time. There was no statistically significant difference in stone clearance rate between the two groups. Four cases of double channels were established in the conventional US-guided PCNL group, while there was only one case in the CEUS-guided PCNL group. In the CEUS-guided PCNL group, most cases (96.7%, 29/30) had no or only mild complications, which were significantly better than the conventional US-guided PCNL group (76.7%, 23/30). The mean postoperative hemoglobin loss in the CEUS-guided PCNL group was 9.5 (range 1-25) g/L, which was significantly lower than 15.5 (range 5-52) g/L in the conventional US-guided PCNL group. Conclusion: The CEUS technique can improve visibility of the nondilated renal collecting system, facilitate selection of suitable calix, and identify renal calix fornix. It also benefits needle placement in patients with a nondilated collecting system.

CT-Guided Percutaneous Gastrostomy without Preliminary Placement of a Nasogastric Tube

Percutaneous radiologic gastrostomy (PRG) requires preliminary gastric inflation through a nasogastric tube (NGT) to safely perform gastric puncture. However, in case of pharyngeal or esophageal obstruction, NGT placement may be impossible even with a hydrophilic angiography catheter and wire. This brief report describes percutaneous computed tomography (CT)-guided gastrostomy with a 2-stick approach without nasogastric insufflation in 13 patients. Technical success rate was 100% with a mean of 1.8 punctures ± 1.0 to access the gastric lumen. Traversal of the colon and liver with a 22-gauge needle was necessary in 4 and 1 patients, respectively. There were no major complications. Minor complications occurred in 6 patients (46%). CT-guided percutaneous gastrostomy is technically feasible with minimal morbidity.

Clinical application of fluoroscopic guided percutaneous antegrade ureteral stents placement for the treatment of malignant ureteral obstruction

OBJECTIVE

To investigate the clinical efficacy and safety of fluoroscopic guided percutaneous antegrade ureteral stents placement used for treatment of malignant ureteral obstruction.

METHODS

Between April 2016 and March 2018, fluoroscopic guided percutaneous ureteral stents was performed in 25 patients, including 7 patients (28%) with bilateral obstruction. The most common cancer diagnoses were cervical cancer (28%), rectal cancer (24%) and colon cancer (16%) among these patients. Clinical data were retrospectively analyzed with respect to the efficacy, safety and outcome of this treatment method.

RESULTS

Percutaneous antegrade placement of ureteral stents was performed in all cases, including 12 ureters that failed in the initial retrograde ureteral stents placement. The median stent patency time for the antegrade ureteral stents were 10.4 (95% CI: 8.3-12.6) months. The primary complications included mild flank pain and discomfort (44%), hematuria (44%), urinary tract infection (8%), bladder irritation symptoms (4%), and arterial bleeding (4%).

CONCLUSION

Fluoroscopic guided percutaneous ureteral stents placement is a safe, efficient procedure and has a high success rate in patients with malignant ureteral obstruction.

Role of percutaneous nephrostomy in end of life prostate cancer patients: a systematic review of the literature

Introduction

Prostate cancer is the most common cancer amongst men in the UK. Treatments for malignant ureteric obstruction consist of percutaneous nephrostomy, ureteric stent insertion, or occasionally other forms of urinary diversion. Our aim was to look at the outcomes of percutaneous nephrostomy (PCN) in patients with advanced prostate cancer and to look at the impact on patient's general health, quality of life, life expectancy and complications after PCN insertion.

Material and methods

A systematic review of the literature was done for all prospective English language articles on PCN in patients with prostate cancer using PubMed, MEDLINE, EMBASE, Scopus, CINAHL, Cochrane library, Clinicaltrials.gov, Google Scholar and individual urological journals from inception to August 2017. While studies involving prostate cancer patients were included, studies on all other mixed pelvic malignancies were excluded.

Results

Seven articles met the inclusion criteria. There were 184 patients, with a mean age of 70 years (range: 51–94 years). PCN was performed for ureteric obstruction due to advanced prostate cancer, patients underwent unilateral (n = 66) or bilateral PCN (n = 118) with conversion to an antegrade stent in 25 patients. Their post-PCN survival varied between 4–31 months and this was longer if they were hormone naïve or showed a good recovery in their renal function. Although the complication rates were low (1–3%), patients spend a high proportion of their lives in the hospital.

Conclusions

PCNs should only be pursued after thoughtful counselling regarding further treatment options and prognosis as these patients with advanced malignancies seem to have reduced survival duration and spend a significant amount of time in hospital.

CT-guided nephrostomy-An expedient tool for complex clinical scenarios

INTRODUCTION & OBJECTIVES

Percutaneous nephrostomy [1] has emerged as a pivotal approach in the therapeutic management of the obstructed urinary tract. A consecutive incorporation of ultrasonic and radiographic guidance, the approach experienced an almost ubiquitious distribution while most centers currently applying either one or both of these tools jointly. However, success of ultrasound-guidance is limited in obese patients and non-dilated uropathy. In turn, fluoroscopy usually requires an opacification of the urinary collecting system by intravenous or antegrade contrast media injection, which might be harmful for already impaired renal function, raise intrapelvic pressure and augment the risk of sepsis and hemorrhage. CT-guided PCN aids in overcoming these limitations. In the current study, we present the experience of a tertiary referral center with this technique.

MATERIALS & METHODS

Epidemiological and clinical data of all patients treated with a CT-guided PCN of native kidneys at the University Hospital Frankfurt between October 2003 and October 2013 were retrospectively collected from the patient charts. Procedural parameters including radiological aspects, technical and therapeutic success, complication and mortality rate have been analyzed statistically.

RESULTS

In total, 140 PCN procedures have been performed in 77 patients with a median age of 69 (± 13). The median body mass index was 27 with 66.6% of patients being overweight or obese. Charlson comorbidity index was 7 ranging 0-16. Indications for PCNs were obstructive uropathy (62.9), urine extravasation (22.9%), urinary tract fistulas (11.4%) and technical reasons (2.8%). In 68.8% of patients, initial diagnosis was malignancy. 56.4% of kidneys were non-dilated before puncture. In 78.4% prone position, otherwise supine oblique position (17.3%) or supine position (4.3%) was used. 71.4% of PCNs were carried out solely under local anesthesia. Technical success has been achieved in 90% with a complication rate of 3.6% (all grade minor B) and was not significantly different between dilated and non-dilated kidneys. 42.9% of fistulas and 64.3% of urinary tract leakages, healed after PCN placement. 30 days mortality rate was 5.2% without being directly associated with the PCN procedure itself.

CONCLUSION

CT-guided PCN is a feasible approach associated with low morbidity. It is particularly useful in complex clinical scenarios e.g. critically ill, newly operated or obese patients as well as non-dilated kidneys. Moreover, it represents a minimally-invasive option for treating leakages and fistulas of the urinary tract.

Contrast-enhanced US-assisted Percutaneous Nephrostomy: A Technique to Increase Success Rate for Patients with Nondilated Renal Collecting System

Purpose To perform a single-center study of contrast material-enhanced ultrasonography (US)-assisted percutaneous nephrostomy (PCN) for patients with nondilated renal collecting system. Materials and Methods An international review board approved this retrospective study with waiver of informed consent for participation, and the study was approved by the Ethical Committee. From November 2011 to September 2015, 47 patients (mean age, 51.9 years ± 16.2 [standard deviation]; range, 18-80 years) with clinical necessity of urinary drainage, urinary diversion, or provision of access to the collecting system and with nondilated renal collecting system who underwent contrast-enhanced US-assisted PCN for 48 kidneys were included. US contrast agent was injected through the puncture needle and the drainage catheter to confirm successful PCN. The technical success rate and complications were evaluated. Relative frequencies with 95% confidence intervals (CIs) were calculated. Results The technical success rate was 100% (47 of 47, 95% CI: 93.8%, 100%) per patient and 100% (48 of 48, 95% CI: 94.0%, 100%) per kidney. For each kidney, the mean number of needle passes was 1.4 ± 0.5 (range, 1-3). The mean duration of the complete procedure was 18.9 minutes ± 4.8 (range, 8-30 minutes). The mean dose of contrast agent was 12.9 mL ± 3.2 (range, 8-25 mL). No major complications were observed. After a follow-up of 1-30 days (mean, 18.4 days ± 10.3), only four patients (four of 47, 8.5%, 95% CI: 2.37%, 20.4%) had minor complications, including one perirenal hematoma seen at US 9 days after the procedure and three patients with transient macroscopic hematuria that lasted 1-2 days. Conclusion Contrast-enhanced US-assisted PCN in patients with nondilated renal collecting system is valuable with high technical success rate. ^© RSNA, 2017.

Percutaneous puncture of renal calyxes guided by a novel device coupled with ultrasound

Purpose:

To evaluate the efficiency of a novel device coupled with ultrassound for renal percutaneous puncture.

Materials and Methods:

After establishing hydronephrosis, ten pigs had three calyxes of each kidney punctured by the same urology resident, with and without the new device (“Punctiometer”). Time for procedure completion, number of attempts to reach the calyx, puncture precision and puncture complications were recorded in both groups and compared.

Results:

Puncture success on the first attempt was achieved in 25 punctures (83%) with the Punctiometer and in 13 punctures (43%) without the Punctiometer (p=0.011). The mean time required to perform three punctures in each kidney was 14.5 minutes with the Punctiometer and 22.4 minutes without the Punctiometer (p=0.025). The only complications noted were renal hematomas. In the Punctiometer group, all kidneys had small hematomas. In the no Punctiometer group 80% had small hematomas, 10% had a medium hematoma and 10% had a big hematoma. There was no difference in complications between both groups.

Conclusions:

The Punctiometer is an effective device to increase the likelihood of an accurate renal calyx puncture during PCNL, with a shorter time required to perform the procedure.

Imaging of iatrogenic complications of the urinary tract: kidneys, ureters, and bladder

Iatrogenic complications of various severities may arise from many, if not all, forms of medical and surgical treatment. Most of these occur in spite of proper precautions. Every system in the human body may be affected, and the urinary tract is no exception. Radiologists are often the first to suspect and identify such iatrogenic injuries and, therefore, awareness of the pertinent imaging findings is vital. This review explores and illustrates many of the common and less common iatrogenic complications affecting the kidney, ureters, and bladder.

Ureteral obstruction following renal transplantation: causes, diagnosis and management

Renal transplantation, first performed successfully in the 1950s, is the treatment of choice for most patients with end-stage renal failure. It confers longer term survival and a better quality of life than do both haemodialysis and peritoneal dialysis. The success of renal transplantation is dependent on the preservation of renal graft function and despite the many advances in surgical techniques, immunosuppressive regimens and supportive therapies, many challenges remain including post-operative ureteral obstruction. This complication can pose a risk to graft, and, occasionally, to patient survival. In this pictorial review, we describe the causes of ureteral obstruction following renal transplantation and illustrate the pivotal role of radiology in both diagnosing and managing these complications.

The skin-to-calyx distance measured by renal ct scan and ultrasound

PURPOSE

We developed a stereotactic device to guide the puncture for percutaneous nephrolithotripsy, which uses the distance from the target calyx to its perpendicular point on skin (SCD) to calculate the needle´s entry angle. This study seeks to validate the use of measurements obtained by ultrasound (US) and computerized tomography (CT) for needle´s entry angle calculation and to study factors that may interfere in this procedure.

MATERIALS AND METHODS

Height, weight, abdominal circumference, CT of the urinary tract in dorsal decubitus (DD) and ventral decubitus (VD), and US of the kidneys in VD were obtained from thirty-five renal calculi patients. SCD obtained were compared and correlated with body-mass index (BMI).

RESULTS

BMI was 28.66 ± 4.6 Kg/m2. SCD on CT in DD was 8.40 ± 2.06cm, in VD was 8.32 ± 1.95cm, in US was 6.74 ± 1.68cm. SCD measured by US and CT were statistically different (p < 0.001), whereas between CT in DD and VD were not. SCD of the lower calyx presented moderate correlation with BMI.

CONCLUSION

SCD obtained by CT in ventral and dorsal decubitus may be used for calculation of the needle´s entry angle. SCD obtained by US cannot be used. A rule for the correlation between BMI and the SCD could not be determined.

Percutaneous nephrostomy: technical aspects and indications

First described in 1955 by Goodwin et al as a minimally invasive treatment for urinary obstruction causing marked hydronephrosis, percutaneous nephrostomy (PCN) placement quickly found use in a wide variety of clinical indications in both dilated and nondilated systems. Although the advancement of modern endourological techniques has led to a decline in the indications for primary nephrostomy placement, PCNs still play an important role in the treatment of multiple urologic conditions. In this article, the indications, placement, and postprocedure management of percutaneous nephrostomy drainage are described.

Emergent percutaneous nephrostomy for the diagnosis and management of pyonephrosis

Emergent percutaneous nephrostomy is a potentially lifesaving procedure with a high technical success rate, minimal morbidity, and long safety record that is often used in the setting of an obstructed and infected renal collecting system (i.e., pyonephrosis). This article discusses all aspects of the emergent placement of nephrostomy catheters including indications, techniques, results, and complications. Differences between emergent and nonemergent placement of percutaneous nephrostomy catheters are also addressed.

Diuretic agent and normal saline infusion technique for ultrasound-guided percutaneous nephrostomies in nondilated pelvicaliceal systems

PURPOSE

Percutaneous nephrostomy (PCN) in a nondilated pelvicaliceal system is technically challenging. We describe an effective method to achieve transient dilatation of the pelvicaliceal system via induction of diuresis using infusion of a diuretic agent in normal saline, therefore allowing easier access to the pelvicaliceal system.

METHODS

Under real-time ultrasound guidance, the technique had been tested in 22 nephrostomies with nondilated system (a total of 20 patients with 2 patients having bilateral nephrostomies) during a 5-year period. Patients were given 40 mg of furosemide in 250 ml of normal saline solution intravenously by rapid infusion. As soon as maximum calyceal dilatation of more than 5 mm was observed, which is usually 15 min later after the end of rapid infusion, patients were positioned obliquely, and PCN procedure under ultrasound guidance was performed.

RESULTS

The procedure was successful in 19 of the nephrostomies in 17 patients with a success rate of 86.36 % per procedure and 85 % per patient in nondilated pelvicaliceal systems. No major nephrostomy-, drug-, or technique-related complications were encountered. The technique failed to work in three patients due to the presence of double J catheters and preexisting calyceal perforation which avoided transient dilation of the pelvicaliceal system with diuresis.

CONCLUSIONS

Diuretic infusion in saline is a feasible and effective method for PCN in nondilated pelvicaliceal systems.

Flexible ureteroscopy-directed retrograde nephrostomy for percutaneous nephrolithotomy: description of a technique

We describe flexible ureteroscopy-directed retrograde nephrostomy access using a puncture wire to achieve renal access. This is a natural extension of modern retrograde intrarenal surgical techniques and a modernization of the original Lawson technique for retrograde nephrostomy tract creation. In appropriately selected patients, this approach is safe and permits reduced radiation exposure. We believe this technique is easy to learn and may overcome the difficult learning curve of antegrade nephrostomy techniques faced by urologists who have not undergone subspecialty training in endourology.

Protection of the renal collecting system during radiofrequency ablation with antegrade cold dextrose infusion

PURPOSE

To evaluate the feasibility and efficacy of antegrade renal cooling during radiofrequency (RF) ablation to protect the renal collecting system in pigs.

MATERIALS AND METHODS

With the approval of the institutional animal care and use committee, RF ablation was planned bilaterally after nephrostomy in 20 kidneys from 10 domestic pigs. A coaxial assembly consisting of a 7-F pigtail catheter and a 12-F arterial sheath was placed at the renal pelvis. Cooled 5% dextrose in water solution was perfused in only one of the kidneys in each pig. A 17-gauge internally cooled tip RF electrode with a 3-cm tip was placed near the renal pelvis with ultrasonographic guidance. On postprocedural days 1 and 7, computed tomography (CT) was performed to evaluate the RF ablation effect, the presence of a fluid collection, and the leakage of contrast material. Ex vivo retrograde pyelography was performed to assess the integrity of the urinary tract after kidney harvest. Histologic findings related to the urothelial damage were scored semiquantitatively.

RESULTS

The mean maximal diameter of the RF ablation area measured at CT and in specimens was not significantly different between cooled and noncooled kidneys. A fluid collection around the RF ablation area was seen in eight of the 10 noncooled kidneys on day 7 CT scans compared with two of the 10 cooled kidneys; the difference was statistically significant (P = .035). Ex vivo retrograde pyelography depicted leakage of contrast material in only the noncooled group. The mean histologic damage score was lower in the cooled group than in the noncooled group.

CONCLUSION

RF ablation after placement of an antegrade cooling system in pig kidneys was feasible. Antegrade cold dextrose infusion of the urinary tract during RF ablation is effective in protecting the renal collecting system without compromising the RF ablation effect.

Percutaneous nephrostomy: native and transplanted kidneys

Percutaneous nephrostomy is a procedure in which access to the renal collecting system of a native (nontransplanted) or transplanted kidney is obtained through the skin, providing external drainage and/or a portal for additional minimally invasive procedures. Such additional minimal invasive procedures include nephrolithotripsy, ureteric stent placement, ureteric dilation, ureteric embolization/obliteration, and rendezvous procedures with cystoscopy. Percutaneous nephrostomy has been proven to be an effective and safe minimally invasive image-guided procedure. This article discusses the indications, techniques, imaging guidance modalities, and outcomes related to percutaneous nephrostomy. Extensions of the nephrostomy procedures, such as ureteric stent placement and nephro-ureteral stent placement are discussed in subsequent articles in this issue.

Percutaneous management of ureteral injuries that are diagnosed late after cesarean section

Objective

We wanted to present the results of percutaneous management of ureteral injuries that were diagnosed late after cesarean sections (CS).

Materials and Methods

Twenty-two cases with 24 ureteral injuries that were diagnosed late after CS underwent percutaneous nephrostomy (PN), antegrade double J (DJ) catheter placement and balloon dilatation or a combination of these. The time for making the diagnosis was 21 ± 50.1 days. The injury site was the distal ureter in all cases (the left ureter: 13, the right ureter: 7 and bilateral: 2). Fifteen complete ureteral obstructions were detected in 13 cases. Ureteral leakage due to partial (n = 4) or complete (n = 3) rupture was noted in seven cases. Two cases had ureterovaginal fistula. All the cases were initially confirmed with antegrade pyelography and afterwards they underwent percutaneous nephrostomy. Balloon dilatation was needed in three cases. Antegrade DJ stents were placed in 10 cases, including the three cases with balloon dilatation. Repetititon of percutaneous nephrostomy with balloon dilatation and DJ stent placement was needed in one case with complete obstruction. All the cases were followed-up with US in their first week and then monthly thereafter for up to two years.

Results

Eighteen ureters (75%) were managed by percutaneous procedures alone. A total of six ureter injuries had to undergo surgery (25%).

Conclusion

Percutaneous management is a good alternative for the treatment of post-CS ureteral injuries that are diagnosed late after CS. Percutaneous management is at least preparatory for a quarter of the cases where surgery is unavoidable.

Effectiveness of three-dimensional fluoroscopy in percutaneous nephrostomy: an animal model study

OBJECTIVES

To present, in an experimental study, an assessment of innovative digital fluoroscopy systems with three-dimensional (3D) reconstruction for use in endourologic applications.

METHODS

The experiment was performed in a pig model. We used 5 pigs. An obstructive uropathy model was created in the right kidney to dilate the urinary tract for group 1. Group 2 consisted of the nondilated left kidney. After selecting the tract on the 3D image, the lower caliceal group was punctured in the 2 kidneys under fluoroscopic control, to assess the efficiency of the 3D reconstruction when selecting the renal calix to be punctured.

RESULTS

The 3D reconstruction system allowed us to obtain reconstruct the pelvis in three dimensions, isolated as the pelvis and renal parenchyma, as well as the adjacent bony relationships. In this study, the success rate was 100% for locating the selected renal calix.

CONCLUSIONS

With this 3D reconstruction system, we were able to obtain a series of images that allowed for the study of the volume of the kidney, perfectly determining its renal calix distribution in the operating room. This enabled us to determine the precise delineation of the target calix. We, therefore, consider this new urologic application of fluoroscopy very useful in surgical planning for antegrade access of the upper urinary tract.

Malignant ureteral obstruction: outcomes after intervention. Have things changed?

PURPOSE

We reviewed the clinical outcome for patients who underwent decompression of malignant ureteral obstruction by analyzing potential prognostic factors, technical success, complication rates and days spent in hospital.

MATERIALS AND METHODS

Retrospective analysis of 102 patients who underwent decompression for malignant ureteral obstruction from 1991 to 2003 was performed. Data on overall survival, prognostic factors, technical failure, complications and days of hospitalization after decompression were examined.

RESULTS

Median overall survival was 6.8 months (95% CI 4.8-9.3) and the overall survival rate at 12 months was 29% (95% CI 21%-39%). Univariate analyses found inferior overall survival associated with patients having metastases (p=0.041), undergoing nephrostomy (p=0.046), prior treatment for cancer (p=0.024) and diagnosis of malignant ureteral obstruction in previously established malignancy (p=0.043). After multivariate analysis poor prognostic factors were presence of metastases (p=0.020) and diagnosis of malignant ureteral obstruction in previously established malignancy (p=0.039). Unfavorable cohorts with 3 or 4 unfavorable baseline risk factors had an inferior overall survival (p=0.008) with 12-month overall survival rates of 12% to 19%. Initial decompression of malignant ureteral obstruction failed in 6% of patients (95% CI 2%-12%) and complications were experienced by 53% (95% CI 43%-63%). Patients were more likely to experience a complication if they had therapy after decompression (p=0.03). The median percentage of their remaining lifetime spent in hospital was 17.4% (range 0.21% to 100%).

CONCLUSIONS

The overall survival of patients with malignant ureteral obstruction remains poor. Prognostic factors for decreased overall survival and prolonged hospital stay have been identified. Although the technical success of decompression has improved the subsequent complication rate is still high.

Multislice CT-angiography in percutaneous postinterventional hematuria and kidney bleeding: Influence of diagnostic outcome on therapeutic patient management. Preliminary results

BACKGROUND

The aims of this study were to assess the value of multislice CT-angiography (MS-CT-A) in percutaneous postinterventional kidney bleeding and to determine the influence of diagnostic outcome on therapeutic patient management. A recommendation for the interdisciplinary patient work-up for the emergency room was offered.

METHODS

Between April 2003 and January 2006, 12 patients with hematuria and clinically suspected renal bleeding underwent MS-CT-A for emergency diagnostic assessment. The spectrum of kidney injuries on CT was analyzed according to an organ-scaling scheme. The efficacy of MS-CT-A with regard to confirmation of active arterial bleeding was evaluated as well as the therapeutic consequences for patient management.

RESULTS

In seven patients (59%) staged grade V renal injury, active renal arterial bleeding was detected on CT-A. Patients immediately underwent therapeutic angiography with confirmation of arterial bleeding and successful embolization. Four patients (33%) were staged grade I renal injury with subcapsular kidney hematoma but no active hemorrhage. Therefore, these patients were not exposed to further therapeutic intervention. One patient (8%) was diagnosed grade II renal injury with superficial cortical renal parenchyma tear and no active bleeding on CT-A.

CONCLUSIONS

MS-CT-A is a valuable, fast and objective emergency tool for assessment of postinterventional renal hemorrhage. Detection of contrast material extravasation to affirm ongoing arterial bleeding and to localize bleeding site at the level of segmental or interlobar renal artery is a predictor for the need for further treatment and justifies therapeutic radiological or surgical management.

Facteurs de risques et prise en charge des complications de la néphrolithotomie percutanée

Extra corporeal shock wave lithotripsy (ESWL) has significantly modified the management of urinary lithiasis. It constitutes usually the first line treatment of urinary calculi sized less than 30 mm. Complex and staghorn calculi may be treated either with percutaneous nephrolithotomy (PCNL) or by flexible uteroscopy (URS) with Holmium laser. PCNL is a minimal invasive technique but it carries a potential risk of complications: infection, bleeding, urinary fistulas and perforations of adjacent organs. PCNL complications may be prevented by the strict respect of technical recommendations; their therapeutic management has been properly codified. In order to reduce the risk of their occurrence, the so-called "mini-perc" (mini-percutaneous technique) has been developed for children and can be applied to adults. Technical details of the two techniques and the treatment of PCNL complications had been described before 1985; the current chapter proposes an update on their prevention and management.

Comment ponctionner un rein pour réaliser une néphrolithotomie percutanée ?

Obtaining a precise percutaneous calyceal puncture gave way to the development of percutaneous nephrolithotomy, one of the first micro-invasive techniques described in urology. Both radiologist and urologist can perform puncture, sometimes in a collaborative effort. However, being followed by a true surgical procedure, it should be done in the O.R; perfect knowledge of the procedure is mandatory for every urologist. Standard guidance uses a fluoroscopic C-arm device, only able to guide the needle precisely towards the apex of the chosen calyx. Moving the C-arm with cephalad tilting will provide 3-D imaging. Ultrasound guidance is an alternative, but might be difficult with non dilated upper tract. CT guidance and retrograde puncture are rarely used. The access is to be adapted according to the patient (adult or child), type of stone (single or multiple access), or kidney position (eutopic or ectopic). Direct ad stable puncture entering the apex of the chosen calyx is a pre-requisite for easy and efficient subsequent nephrolithotomy.

Percutaneous nephrostomy and antegrade ureteral stenting: technique-indications-complications

In this review the technique, indication for and complications of percutaneous nephrostomy (PCN) and antegrade ureter stent insertion are described. In the majority of the cases PCN is performed to relieve urinary obstruction, which can be of benign or malignant nature. Another indication for PCN is for treatment of urinary fistulas. PCN can be performed under ultrasound and/or fluoroscopic guidance, with a success rate of more than 90%. The complication rate is approximately 10% for major and minor complications together and 4-5% for major complications only. Percutaneous antegrade double-J stent insertion usually is performed if retrograde ureter stenting has not been successful. However, especially in malignant obstructions, the success rate for antegrade stenting is higher than for retrograde transvesical double-J stent insertion. In the case of severe infection and bleeding after PCN JJ-stent insertion may be contraindicated so long as there is no sufficient concomitant drainage via a PCN . Lower urinary tract dysfunction should be excluded before stent placement. The complication rate is 2-4%. Consequent stent surveillance with regular stent exchange is mandatory.

Percutaneous Treatment of the Obstructive Uropathy

Purpose

to analyse the technical aspects, the patient's selection criteria, and some useful tactics to reduce the complications of percutaneous nephrostomy and of other interventional procedures to temporarily treat obstructive uropathy (OU), such as double J stent insertion, dilatation of the stricture using high-pressure balloon catheters, removal of renal or ureteral calculi, fistulas treatment.

Materials and Methods

a fluoroscopy table and an ultrasonographic guidance are key elements. Two techniques are employed, either the Seldinger type (wire-guided catheters) or the trocar needle type. Sole contraindication: uncorrectable severe coagulopathy. Most important risk factors are: dendritic calculus, non corrected high blood pressure, obesity, small size kidney, severe scoliosis.

Results

high technical success of the procedure in case of dilated collecting systems (98%); it is minor without dilatation (85%).

Conclusion

percutaneous nephrostomy is indicated in 87% of obstructive uropathy cases. It represents the basic technique allowing other interventional procedures to treat obstructive uropathy; it should be performed by most radiologists following an adequate training with technique and materials.