The place of computed tomography as a guidance modality in percutaneous nephrostomy: analysis of a 10-year single-center experience

Iatrogenic vascular complications of non-vascular percutaneous abdominal procedures

PURPOSE

The purpose of this paper is to compile and present all of the reported vascular complications that resulted from common non-vascular abdominal procedures in the literature. Non-vascular procedures include, though are not limited to, percutaneous abscess/fluid collection drainage (PAD), percutaneous nephrostomy (PN), paracentesis, percutaneous transhepatic cholangiography (PTC)/percutaneous biliary drainage (PBD), percutaneous biliary stone removal, and percutaneous radiologic gastrostomy (PG)/percutaneous radiologic gastrojejunostomy (PG-J). By gathering this information, radiologists performing these procedures can be aware of the associated vascular injuries, as well as take steps to minimize risks.

METHODS

A literature review was conducted using the PubMed database to catalog relevant articles, published in the year 2000 onward, in which an iatrogenic vascular complication occurred from the following non-vascular abdominal procedures: PAD, PN, paracentesis, PTC/PBD, percutaneous biliary stone removal, and PG/PG-J. Biopsy and tumor ablation were deferred from this article.

RESULTS

214 studies met criteria for analysis. 28 patients died as a result of vascular complications from the analyzed non-vascular abdominal procedures. Vascular complications from paracentesis were responsible for 19 patient deaths, followed by four deaths from PTC/PBD, three from biliary stone removal, and two from PG.

CONCLUSION

Despite non-vascular percutaneous abdominal procedures being minimally invasive, vascular complications still can arise and be quite serious, even resulting in death. Through the presentation of vascular complications associated with these procedures, interventionalists can improve patient care by understanding the steps that can be taken to minimize these risks and to reduce complication rates.

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).

Emergency Decompression of Obstructive Uropathy Using Percutaneous Nephrostomy: Disease Pattern and Treatment Outcome at Two Urology Centers in Ethiopia

Purpose

Obstructive uropathy (OU) is a potentially life-threatening urologic emergency that requires urgent decompression. Percutaneous nephrostomy (PCN) is a commonly performed procedure to decompress OU. The objective of this study is to assess disease patterns and treatment outcome at two urologic centers in Ethiopia.

Methods

A cross-sectional study was conducted on 110 patients who underwent emergency PCN from October 1, 2019 to September 30, 2020. Data were collected by a retrospective chart review. SPSS 25 was used for analysis. Descriptive statistics and logistic regression were utilized to assess disease pattern and significant predictors. A p-value of <0.05 on multivariate logistic regression was considered statistically significant.

Results

Females accounted for 70% of cases and mean age at presentation was 48 ± 12.9 years. Bilateral OU was diagnosed in 60% of patients and 77.3% of obstructions occurred at the level of the ureter. Malignancies were diagnosed in >80% of patients among which cervical cancer was the commonest (37.3%) followed by bladder cancer (17.3%). Acute kidney injury (AKI) accounted for 70% of the presenting indications for PCN. Success rate after emergency PCN was 75.5% and 41.8% of the cases developed post-procedure complications. Factors that predicted successful outcome include male gender [AOR = 5.72 (1.13–28.92), 95% CI; p = 0.035], severe hydronephrosis pre-operatively [AOR = 7.12 (1.32–38.45), 95% CI; p = 0.022], and use of combined imaging (ultrasound and fluoroscope) to guide PCN [AOR = 12.91 (1.13–46.54), 95% CI; p = 0.039]. On the other hand, postoperative complication is a negative predictor [AOR = 0.26 (0.08–0.86), 95% CI; p = 0.027].

Conclusion

In this study, overall success of emergency PCN is low. Presence of severe hydronephrosis predicts technical ease and better outcome of PCN. Procedures performed under ultrasound and fluoroscope guidance also improve outcome. Postoperative complication rate is high in this study and mandates strict preventive measures as it predicts unfavorable outcome.

Deep-learning-aided forward optical coherence tomography endoscope for percutaneous nephrostomy guidance

Percutaneous renal access is the critical initial step in many medical settings. In order to obtain the best surgical outcome with minimum patient morbidity, an improved method for access to the renal calyx is needed. In our study, we built a forward-view optical coherence tomography (OCT) endoscopic system for percutaneous nephrostomy (PCN) guidance. Porcine kidneys were imaged in our experiment to demonstrate the feasibility of the imaging system. Three tissue types of porcine kidneys (renal cortex, medulla, and calyx) can be clearly distinguished due to the morphological and tissue differences from the OCT endoscopic images. To further improve the guidance efficacy and reduce the learning burden of the clinical doctors, a deep-learning-based computer aided diagnosis platform was developed to automatically classify the OCT images by the renal tissue types. Convolutional neural networks (CNN) were developed with labeled OCT images based on the ResNet34, MobileNetv2 and ResNet50 architectures. Nested cross-validation and testing was used to benchmark the classification performance with uncertainty quantification over 10 kidneys, which demonstrated robust performance over substantial biological variability among kidneys. ResNet50-based CNN models achieved an average classification accuracy of 82.6%±3.0%. The classification precisions were 79%±4% for cortex, 85%±6% for medulla, and 91%±5% for calyx and the classification recalls were 68%±11% for cortex, 91%±4% for medulla, and 89%±3% for calyx. Interpretation of the CNN predictions showed the discriminative characteristics in the OCT images of the three renal tissue types. The results validated the technical feasibility of using this novel imaging platform to automatically recognize the images of renal tissue structures ahead of the PCN needle in PCN surgery.

Comparison of contrast-enhanced ultrasound versus conventional ultrasound-guided percutaneous nephrolithotomy in patients with nondilated collecting system: a randomized controlled trial

OBJECTIVE

To compare the safety, effectiveness, and feasibility of contrast-enhanced ultrasound (CEUS) versus conventional ultrasound-guided percutaneous nephrolithotomy (PCNL) in patients with nondilated collecting system.

METHODS

Between July 2018 and July 2020, 160 kidney stone patients with nondilated collecting system planned for PCNL were randomly assigned into two groups, CEUS with retrograde ureteral contrast injection and conventional ultrasound with retrograde ureteral normal saline injection. Patient's demographics, the success rate of puncture, success rate of a single-needle puncture, number of punctures, puncture time, perioperative outcomes, stone-free rate, and incidence of complications were compared.

RESULTS

The success rate of a single-needle puncture for CEUS-guided PCNL was higher than that in the conventional ultrasound group (88.5% vs. 73.7%, p = 0.02). Patients performed with CEUS-guided PCNL required less needle passes (p = 0.02), shorter needle puncture time (p = 0.031), and shorter channel establishment time (p = 0.04) than those guided with conventional ultrasound. The postoperative hemoglobin decrease in the CEUS-guided PCNL group was less than that of the control group (p = 0.02). There was no significant difference in operating time, length of hospital stays, kidney function change, and complications between the two groups (p > 0.05). The 1-month stone-free rate was 94.9% in the CEUS group and 90.8% in the control group (p > 0.05).

CONCLUSIONS

Compared with conventional ultrasound, CEUS-guided PCNL may facilitate ultrasound-guided PCNL for patients without hydronephrosis, and benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1800016981 KEY POINTS: • Compared with conventional ultrasound, CEUS-guided PCNL is a safe and efficacious procedure for kidney stone patients with nondilated collecting system. • Compared with conventional ultrasound, CEUS-guided PCNL benefited with a higher success rate of a single-needle puncture, less needle passes, shorter puncture time, and lower postoperative Hb drop. • CEUS-guided PCNL associated with the more accurate needle puncture and acceptable complications.

Prospective audit of complications after ultrasonography-guided percutaneous nephrostomy for upper urinary tract obstruction using modified Clavien classification system

Introduction

Percutaneous nephrostomy (PCN) is a commonly performed intervention in urology for various benign and malignant conditions causing upper urinary tract obstruction. We present a prospective audit of complications of ultrasonography (USG) guided PCN using modified Clavien classification system (mCCS).

Methods

The data were prospectively collected for 368 PCN performed in 344 patients from June 2015 to January 2017, for various benign and malignant diseases causing upper urinary tract obstruction. Patients were followed for 1 month, and complications arisen of PCN were noted.

Results

PCN was successful in 356 renal units. The 12 patients in which PCN failed was due to minimal pelvicalyceal dilatation and PCN was successfully performed after 48 h by a senior urologist. 207 patients had malignant disease and 161 patients had benign condition. Most common malignant disease was carcinoma cervix. 238 were noninfected while 130 had infected renal units. 62 (16.84%) patients had Grade I (self-limiting hematuria/cot/debris/fever). 37 (10.0%) patients had Grade II (7 - transfusion and 30 - urinary tract infection). 34 (9.2%) had Grade III a (repositioning/change/reinsertion of PCN tube under local anesthesia) and 4 (1.1%) had Grade III b (repositioning under anesthesia). 8 (2.2%) Grade IV a (Sepsis), 0 Grade IV b, and 0 Grade V complications were observed.

Conclusion

USG-guided PCN is a safe, minimally invasive, and effective procedure for upper urinary tract diversion with a low rate of morbidity. Individual complications are within the threshold limits set by the American College of Radiology, the Society of Interventional Radiology. mCCS is well applicable and easily reproducible tool for reporting the complications of PCN.

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.

Flat detector cone beam CT-guided nephrostomy using virtual navigation in patients with iatrogenic ureteral injury

PURPOSE

To evaluate the feasibility of flat detector cone beam computed tomography (CBCT)-guided nephrostomy using virtual navigation in patients with iatrogenic ureteral injury.

MATERIALS AND METHODS

A retrospective review of percutaneous nephrostomy (PN) revealed the use of CBCT with 3D virtual navigation guidance in 42 procedures (40 patients) for patients with iatrogenic ureteral injury. All procedures were shown as second-line interventions after failed ultrasound-guided nephrostomy. Data on technical success rate, procedure time, puncture performance, radiation exposure, complications, and clinical success were collected.

RESULTS

The technical success rate was 95.2% (40/42). The mean puncture performance score was 4.4 ± 1.0, and the procedure time was 25.2 ± 3.1 min, resulting in a mean effective exposure dose of 5.9 ± 2.3 mSv. There were no serious complications. During the mean follow-up periods of 11.4 months (range 6-19), clinical success rates following drainage were 72.5% (29/40), and ten cases (25%) had secondary surgical treatments.

CONCLUSION

CBCT with 3D virtual navigation is a feasible technique for PN with reasonable exposure dose and can serve as a second-line intervention after failed ultrasound guidance.

The ideal puncture approach for PCNL: Fluoroscopy, ultrasound or endoscopy?

Percutaneous renal access is a common procedure in urologic practice. The main indications are drainage of an obstructed and hydronephrotic kidney and antegrade renal access prior to percutaneous renal surgeries such as percutaneous nephrolithotomy (PCNL) and percutaneous endopyelotomy (EP). The contraindications for this technique are patients with history of allergy to topical or local anesthesia and patients with coagulopathy. The creation of a percutaneous tract into the renal collecting system is one of the important steps for percutaneous renal access. This step usually requires imaging. The advantages and disadvantages of each modality of image guidance are controversial. We performed a structured review using the terms: Percutaneous nephrostomy, guidance, fluoroscopy, ultrasonography, computed tomography (CT) scan, and magnetic resonance imaging (MRI). The outcomes are discussed.

Intramural dissection of the renal collecting system during percutaneous nephrostomy: computed tomography findings of a rare complication

Intramural dissection of the renal collecting system during percutaneous nephrostomy (PCN) is a rare complication that can be challenging to diagnose. In this report, we describe the computed tomography (CT) and fluoroscopic findings of urothelial dissection during CT-guided PCN in a 65-year old patient with an obstructed congenital solitary left kidney due to an urinary bladder carcinoma. To our knowledge, CT findings of urothelial dissection have not yet been described.

Multimedia article. Navigated renal access using electromagnetic tracking: an initial experience

BACKGROUND AND AIM

Navigation systems are promising tools for improving efficacy and safety in surgical endoscopy and other minimally invasive techniques. The aim of the current study is to investigate electromagnetic tracking (EMT) for navigated renal access in a porcine model.

METHODS

For our proof-of-principle study we modified a recently established porcine ex vivo model. Via a ureteral catheter which was placed into the desired puncture site, a small sensor was introduced and located by EMT. Then, a tracked needle was navigated into the collecting system in a "rendezvous" approach. A total of 90 renal tracts were obtained in six kidneys using EMT, with a maximum of three punctures allowed per intervention. For each puncture, number of attempts to success, final distance to probe, puncture time, and localization were assessed. We compared absolute and relative frequencies using the chi-square test and applied the Mann-Whitney U-test for continuous variables.

RESULTS

No major problems were encountered performing the experiment. Access to the collecting system was successfully obtained after a single puncture in 91% (82/90) and within a second attempt in the remaining 9% (8/90). Thus, a 100% success rate was reached after a maximum of two punctures. Location of the calyx did not have a significant effect on success rate (p = 0.637). After a learning phase of 30 punctures, higher success rate (96% versus 83%; p = 0.041) was accomplished within shorter puncture time (14 versus 17 s; p = 0.049) and with higher precision (1.7 versus 2.8 mm; p < 0.001).

CONCLUSIONS

With respect to other established techniques, use of EMT seems to decrease the number of attempts and procedural time remarkably. This might contribute to greater safety and efficacy when applied clinically. The presented approach appears to be promising, especially in difficult settings, provided that in vivo data support these initial results.

Computed tomography for percutaneous renal access

Abstract Successful percutaneous nephrolithotomy (PCNL) relies on appropriate preoperative planning and optimal percutaneous access. CT has now become the standard imaging tool for PCNL. For percutaneous renal access, CT may be used for planning access, guiding access, and in the follow-up after access. In this review, we discuss the role of each aspect for percutaneous access in PCNL. In particular, we describe the technique for gaining access using CT, a valuable method in the difficult collecting system.

Imaging in percutaneous nephrolithotomy

Image guidance is a critical factor for the performance of urologic interventions. Percutaneous minimally invasive procedures have been developed and are being used with constantly increasing frequency. Procedures such as percutaneous nephrolithotomy (PCNL) are not performed without any image guidance. Recent developments in medical imaging, such as three-dimensional radiographic fluoroscopy, CT, and magnetic resonance (MR) fluoroscopy, four-dimensional ultrasonography, and image fusion techniques, propose a new generation of image-guidance tools that promise to improve patient care. These developments have been used or have the potential to be used in PCNL and other urologic interventional procedures. Moreover, advanced needles and needle guidance systems provide a new perspective for the nephrolithotomy suite of the future. The current review presents existing imaging technology in PCNL and interventional urology as well as advanced imaging techniques that are being or are expected to be evaluated in PCNL practice.