Ultrasound-guided renal access and balloon dilation for PCNL in the prone position: results of a multicenter prospective observational study

PURPOSE

To investigate the safety and efficacy of ultrasound-guided renal access and tract dilation using balloon dilators, as well as to identify suitable patients for this technique.

METHODS

Consecutive patients undergoing ultrasound-guided PCNL using balloon dilators between December 2019 and June 2020 in seven large medical centers from China were prospectively enrolled. Demographic and perioperative parameters of the patients were collected. Logistic regression analysis was used to analyze factors that would affect the success rate of tract establishment using ultrasound-guided renal access and balloon dilation.

RESULTS

A total of 170 patients were included in this study, among whom, 91.18% of the (155/170) patients had a successful tract establishment under ultrasound guidance on the first attempt. The stone-free rate was 83.5% and postoperative complications occurred in 14 patients (8.23%). In univariate analysis, history of ipsilateral surgery (p = 0.026), and stone diameter (p = 0.01) were significantly associated with tract establishment failure, while a larger width of the target calyx (p = 0.016) and the presence of hydronephrosis (p = 0.001) were significantly associated with a successful tract establishment. In multivariate analysis, only hydronephrosis in target calyx (p = 0.027) was a favorable factor for successful tract establishment, and the history of ipsilateral renal surgery (p = 0.012) was the only independent risk factor for failure of tract establishment.

CONCLUSION

It was safe and effective to establish percutaneous renal access with balloon dilation under whole-process ultrasound monitoring during PCNL. Furthermore, patients with a hydronephrotic target calyx and without history of ipsilateral renal surgery were most suited to this technique. Trial registration CHiCTR1800014448.

A Different and Novel Alternative (ADANA) Renal Access Technique when CT or USG Guidance Is Inadequate in Case of Retro-Renal Colon

INTRODUCTION

Computed tomography (CT) or ultrasonography (USG)-guided renal access for percutaneous nephrolithotomy (PNL) is not suitable in all cases with retro-renal colon (RRC) due to anatomical and technical restrictions. We would like to describe our novel technique that permits standard subcostal renal access with a small incision for these patients.

METHODS

This method was performed on adult patients with severe RRC and complex renal stones who were not suitable for renal access with CT or USG guidance. Time from skin incision to puncture needle insertion, incision length, stone-free rate (SFR), and complications were evaluated.

SURGICAL TECHNIQUE

The appropriate renal calyx for renal access was identified with retrograde pyelography. The skin closest to the identified calyx was incised and retroperitoneum visualized. The RRC was swept laterally by blunt dissection to obtain a safe puncture line. The retractors were placed to keep the colon away from the incision. Then, the puncture needle was placed over Gerota's fascia. After this, the puncture needle was inserted into the targeted calyx under fluoroscopic guidance. The insertion of guidewire and the rest of the procedure such as dilatation and insertion of Amplatz sheath were performed under same maneuver.

RESULTS

A total of 1,348 patients were treated with PNL between January 2016 and November 2019. Our group consisted of 16 adult patients with a median age of 44.8 years (7 females and 9 males) who underwent PNL with our new access technique. SFR and clinically insignificant residual fragment (CIRF) rate were 72.5 and 14.2%, respectively. The median access time was 22.2 min (range: 15-30 min). The median skin incision length was 3.7 (range: 3.0-4.5) cm. The average skin incision length was 3.7 cm. The SFR and CIRF rate were 72.5 and 14.2%, respectively. We did not observe any complication related to our access technique.

CONCLUSION

Our novel access technique created a safe anatomical route for standard subcostal renal access with acceptable incision length and very low complication rate.

Present indications and techniques of percutaneous nephrolithotomy: What the future holds?

The purpose of the review was to present the latest updates on percutaneous nephrolithotomy (PCNL) procedure in terms of indications and evolving techniques, and to identify the advantages and disadvantages of each modality. The data for this review were collected after a thorough PubMed search in core clinical journals in English language. The key words included “PCNL” and “PNL” in combination with “indications”, “techniques”, “review” and “miniaturized PCNL”. Publications relevant to the subject were retrieved and critically reviewed. Current European and American Urology Association Nephrolithiasis Guidelines were included as well. The indications for standard PCNL have been changed through the past decade. Despite evolution of the procedure, innovations and the development of new technical approaches, the indications for miniaturized PCNL have not been standardized yet. There is a need for well-constructed randomized trials to explore the indications, complications and results for each evolving approach. A continuous reduction of tract size is not the only revolution of the last years. There is constant ongoing interest in developing new efficient miniature instruments, intracorporeal lithotripters and sophisticated tract creation methods. We can summarize that, PCNL represents a valuable well-known tool in the field of endourology. We should be open minded to future changes in surgical approaches and technological improvements.

A Comparative Study of Antegrade Air Pyelogram and Retrograde Air Pyelogram for Initial Puncture Access during Percutaneous Nephrolithotomy

INTRODUCTION

Access into the collecting system is considered to be the most critical step for Percutaneous Nephrolithotomy (PCNL).

AIM

The present study provides a comparative view into antegrade air pyelography and retrograde air pyelography procedures for percutaneous renal access.

MATERIALS AND METHODS

A cross-sectional study was conducted on 100 patients with radiopaque renal calculi indicated for PCNL procedure. These patients were randomly assigned to two groups namely antegrade air pyelogram group (Group I) and retrograde air pyelogram group (Group II). In antegrade air pyelogram group, the collecting system was delineated by targeting the renal stone using a 22 gauge spinal needle where the patients were in the prone position. In another group, the collecting system was delineated by retrograde air pyelogram under fluoroscopy guidance. The method of tract dilatation and stone extraction were the same in both groups for comparison of outcome and complication.

RESULTS

The mean age of patients was 41.7±13 and 41.4±13.6 years in Group-I and Group-II respectively. The male to female ratio in Groups I and II was 35/15 (70.00%) and 38/12 (76.00%) respectively. In Group-I the average duration of access was 2.66±1.0 minutes after prone positioning whereas it was recorded to be 19.48±5.0 minutes in Group-II, after lithotomy followed by prone positioning of the patient. Duration of radiation exposure was almost similar in both groups. Additional procedural cost was significantly higher in Group II.

CONCLUSION

Our study indicated that access for PCNL using antegrade air pyelogram can be a cost-effective and acceptable alternative to retrograde air pyelogram with decreased access time.

Does the presence of a percutaneous renal access influence fluoroscopy time during percutaneous nephrolithotomy?

Objective

The aim of this study was to assess whether the presence of a pre-formed percutaneous renal access (PCA) had any effects on fluoroscopy time (FT) during percutaneous nephrolithotomy (PCNL).

Methods

After ethics approval was obtained, medical records of all patients who underwent PCNL between 2009 and 2013 at a tertiary stone referral centre were retrospectively reviewed. Patients with and without pre-formed PCA undergoing PCNL were compared. Patients who underwent second-look PCNL and those who had their access inserted by interventional radiology constituted the group with pre-formed PCA.

Results

A total of 185 PCNLs were reviewed. The mean patient age was 55.2 ± 1.0 years with mean body mass index (BMI) of 27.8 ± 0.5 kg/m² and male gender of 63.8%. The mean stone size was 618.4 ± 47.0 mm² with mean Guy's grade of 2.3 ± 0.7 and mean S.T.O.N.E. score of 7.6 ± 0.1. The mean operative time was 98.7 ± 2.6 min with mean FT of 113.4 ± 4.5 s. The overall stone-free rate was 71.9% with complication rate of 16.2%. When compared with PCNLs without pre-formed PCA, PCNLs with pre-formed PCA were associated with significantly shorter FT (120.6 ± 5.1 vs. 77.5 ± 6.7 s; p < 0.001) and significantly lower estimated blood loss (EBL) (p = 0.01). On multivariate analysis, PCNLs with pre-formed PCA were associated with significantly shorter FT (B. coefficient = −43.2 (95%CI: −66.4 to −20); p < 0.001) and lower EBL (p = 0.02).

Conclusion

PCNLs with pre-formed PCA were associated with significantly lower FT and EBL when compared with PCNLs without pre-formed PCA.