Minituriazed percutaneous nephrolithotomy: what does it mean?

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Reliability of nephrolithometric nomograms in patients treated with minimally invasive percutaneous nephrolithotomy: A precision study

Objectives

The study aimed to evaluate quality of nephrolithometric nomograms to predict stone-free rates (SFRs) and complication rates (CRs) in case of minimally invasive percutaneous nephrolithotomy (PNL). In the last decade, nomograms have been introduced to estimate the SFRs and CRs of PNL. However, no data are available regarding their reliability in case of utilization of miniaturized devices. Herein we present a prospective multicentric study to evaluate reliability of Guy's stone score (GSS), the stone size, tract length, obstruction, number of involved calyces, and essence of stone (S.T.O.N.E.) nephrolithometry score and Clinical Research Office of the Endourological Society (CROES) score in patients treated with minimally invasive PNL.

Methods

We evaluated SFRs and CRs of 222 adult patients treated with miniaturized PNL. Patients were considered stone-free if no residual fragments of any size at post-operative unenhanced computed tomography scan. Patients demographics, SFRs, and CRs were reported and analyzed. Performances of nomograms were evaluated with the area under the curve (AUC).

Results

We included 222 patients, the AUCs of GSS, CROES score, and S.T.O.N.E. nephrolithometry score were 0.69 (95% confidence interval [CI] 0.61-0.78), 0.64 (95% CI 0.56-0.73), and 0.62 (95% CI 0.52-0.71), respectively. Regarding SFRs, at multivariate binomial logistic regression, only the GSS had significance with an odds ratio of 0.53 (95% CI 0.31-0.95, p=0.04). We did not find significant correlation with complications, with only a trend for GSS.

Conclusion

This is the first study evaluating nomograms in miniaturized PNL. They still show good reliability; however, our data showed lower performances compared to standard PNL. We emphasize the need of further studies to confirm this trend. A dedicated nomogram for minimally invasive PNL may be necessary.

The use of ureteral access sheath during mini-percutaneous nephrolithotomy with high-power holmium YAG laser

PURPOSE

To present our preliminary results and describe a technical modification of mini-PCNL (12Fr) with the insertion of a ureteral access sheath (UAS) to facilitate the procedure.

METHODS

A prospective study for the time period of January 2020 to January 2021 was conducted including patients with renal stones sized ≤ 25 mm in whom prone mini-PCNL (tract size 12Fr) together with the retrograde insertion of UAS was performed. All patients had been prestented at least 1 week prior to the planned surgery. A single-step tract dilation to 12Fr diameter was performed through a nonpapillary medial puncture. The lithotripsy was achieved using high-power holmium yttrium aluminum garnet laser (Ho:YAG) with the 60 W power setting (40 Hz and 1.5 J). The follow-up investigations were planned at 1-month after the surgery.

RESULTS

In total, 32 patients with the median age and stone size of 56.5 (IQR = 53-62) years and 20.8 (IQR = 19.3-22.7) mm were included. The median operative and cumulative fluoroscopy time were 34.0 (IQR = 29.9-37.5) and 1.9 (1.8-2.1) min, respectively. The stone-free rate (SFR) at 1-month follow-up was 93.8% (30/32). Only one patient developed a fever and required prolonged antibiotic administration. None of the patients experienced clinically significant bleeding.

CONCLUSION

Our preliminary results showed that the use of UASs during mini-PCNL procedures is feasible and provides directed evacuation of the stone fragments reaching 93.8% SFR at a 1-month follow-up. Future well-designed studies are necessary to prove our findings.

Non papillary mini-percutaneous nephrolithotomy: early experience

PURPOSE

This study aims to evaluate the non-papillary puncture for mini-PCNL in terms of safety and efficacy.

METHODS

A total number of 32 patients were subjected to mini-PCNL by the performance of non-papillary punctures over 6 months. One-step track dilation to 22 Fr took place in all cases. An 18 Fr nephroscope (Slender, Karl Storz GmbH, Germany) and an ultrasound lithotripter (Lithoclast Master, EMS S.A, Switzerland) with 9.9 Fr probe was used. Demographics and perioperative data are prospectively collected from an institutional board-approved database and the presented data were retrospectively collected.

RESULTS

The average cumulative stone size was 23.53 ± 6.6 mm. Mean operative time was 44.6 ± 13.44 min and primary stone-free rate after PCNL was 96% and 85.7% for single and multiple access, respectively. Second access was performed in seven cases, all of which had multiple stones. Mean hemoglobin drop was 1.23 ± 0.88 gr/dL. The patients stayed 2.56 ± 0.98 days in the hospital. Overall complication rate was 9.37%, without encountering any severe bleeding complication.

CONCLUSION

Using non-papillary access for mini-PCNL did not result in significant blood loss and need for transfusions. The respective data were directly comparable to contemporary literature and the safety of mini-PCNL by a non-papillary approach could be advocated.

The Pattern of Day Case (Ambulatory) Percutaneous (PCNL): A Descriptive Retrospective Study from a Tertiary Care Hospital

Background: Percutaneous nephrolithotomy (PCNL) has experienced remarkable development and alteration since it was first described in 1976 by Fernstorm et al. It has also experienced miniaturization of equipment, improvement in operative systems, and refining renal access methods leading to the achievement of maximum clearance of stone while causing minimal morbidity. For example, in endourological practice, when the patient is subjected to PCNL, he traditionally needs programmed inpatient admission, as part of their recovery, it is applicable as an outpatient method in properly selected cases. Objectives: We aimed at evaluating the safety and applicability of the outpatient PCNL procedure. Methods: This retrospective study was done on 210 cases of tubeless PCNL performed by a single urologist at our institute from January 2016 to January 2019. Patients’ mean age (134 males and 76 females) was 57 ± 11.8 years, and 7 patients aged 8 - 12 years. There were 71 pelvic or calyceal solitary stones, 62 non-complete staghorn stones, 17 ureteral stones, 32 renal + ureteric stones (simultaneous renal and ureteral stones) , and 28 complete staghorn stones. The average stone size was 3.5 ± 2.8 (range: 0.7 to 11.8 cm). Results: The mean operation duration was 85.0 ± 29.4 min, and the mean hospital stay was 21.7 ± 3.4 h. Out of 210 patients, 6 patients had longer stay due to high-grade fever and 3 patients due to severe pain, and also 7 patients refused discharge due to personal and social reasons. Our ambulatory PCNL rate was 97 % ( 194 out of 210). Within 72 h, 5 patients were readmitted due to high-grade fever, 3 patients due to haematuria, and 4 patients due to pain and dysuria, and all patients were discharged 2 - 4 days after conservative treatment. Thus, the readmission rate was 6.18% (12 cases were readmitted out of 194 cases). Patients showed a blood transfusion rate of 1.4 %. Also, 19 cases (9.02%) were found with post-operative fever, and no urosepsis was reported. No pulmonary complications and mortality were noted. No re-exploration was done, and no major leak was noted. The angio-embolization rate was 0.59%. We did not use HEMO-SEAL technology, cautery, or suture in the tracks. Conclusions: In conclusion, the outpatient PCNL procedure is an applicable and feasible procedure under selected criteria; however, more investigations using a larger sample size are needed.

Minimally invasive percutaneous nephrolithotomy (PCNL): Techniques and outcomes

Minimally invasive percutaneous nephrolithotomy (PCNL) was introduced to decrease the morbidity of the standard PCNL (sPCNL). Thereafter, many modifications and techniques have been presented with the introduction of different miniaturized PCNL (mPCNL) techniques, such as micro-PCNL and ultra-mini-PCNL (UMP). As of present, none of the techniques has displaced the sPCNL. Nonetheless, mini-PCNL has continuously widening indications and has been proposed to have significant advantages over sPCNL. In the current review, each technique is presented while discussing the advantages and disadvantages of each approach. A comprehensive review of the current literature has been performed. Articles related to the topic were retrieved and critically analyzed. Less peri-operative bleeding and shorter hospital stay were the most important advantages advocated for mini-PCNL. Although the performance of mini-PCNL is safe, the utilization of micro-PCNL and UMP should be done with caution.

Safety and efficacy of Chinese minimally invasive percutaneous nephrolithotomy in the management of renal stones ≤ 2 cm: a single-center experience

Background

The goal for using smaller caliber instruments in PNL was to reduce the access-related complications and to decrease morbidity. The objective of this study was to evaluate the safety and efficacy of Chinese minimally invasive percutaneous nephrolithotomy (MIPNL) in the treatment of renal stones ≤ 20 mm.

Results

Sixty-seven patients completed the study protocol. The mean age was 41.10 ± 13.99 years (range 18–68 years). There were 43 (64%) male and 24 (36%) females. The mean stone size was ranged from 78.5 to 439.6 mm2 (mean ± SD 172.48 ± 69.54 mm2). The overall SFR was (82%). Twelve (18%) needed post-MIPNL auxiliary procedure, in the form of second MIPNL in 3 (4.5%) cases, SWL in 7 (10%), and RIRS in 2 (3%) cases. The intraoperative complication was present in four patients (5%) include bleeding necessitate blood transfusion in one patient (1.5%) and renal collecting system perforation 3 (4.5%). The postoperative complication was urine leakage 5 (7.5) and fever in 6 (9%) of patients.

Conclusion

Chinese MIPNL is safe and effective method for treatment of renal stone ≤ 20 mm size with satisfactory SFR and low complication rate when SWL failed or contraindicated. It is considered a feasible treatment alternative to standard PNL, in the absence of flexible URS or miniature nephroscope.

Experience of percutaneous nephrolithotomy with the creation of nephrostomy tract by plasma vaporization

PURPOSE

To share our 7-year experiences of a safe and effective method for tract creation in percutaneous nephrolithotomy (PCNL).

METHODS

A total of 143 patients had received this kind of method for renal stone disease at our institute from May 2010 to December 2016. Finally, 130 patients with complete data were included. All patients underwent a bipolar resectoscope mounted with a plasma vaporization (PV) button electrode for tract creation. Data analysis included procedure time, length of hospital stays, blood transfusion rate, any early and late complications, renal function, and stone-free rate.

RESULTS

The mean age of patients was 56.5 years (range 26-84 years). Noticeably, no blood transfusion was necessary in this series. Mean length of post-operative stay duration was 2.6 ± 1.1 days. The average operating time was 46 min. Stone-free rate was 93.3% in the non-staghorn calculi group. There was no significant difference in change in renal function after the operation (P = 0.884). All posto-perative complications were Clavien grade 1 including fever (16.9%) and urine leak (1.5%) etc. There was no major complication.

CONCLUSIONS

Based on zero blood transfusion rate, no major complication, and shorter post-operative stay duration (2.6 days), the PV technique is safe and effective for less blood loss in comparison with other techniques for creating the nephrostomy tract for PCNL.

Safety and Efficacy of Day-case Percutaneous Nephrolithotomy: A Systematic Review from European Society of Uro-technology

CONTEXT

Day case or ambulatory percutaneous nephrolithotomy (PCNL) has risen over the last few years with the aim of discharging patients within 24h.

OBJECTIVE

We perform a systematic review of literature to evaluate the outcomes of day-case PCNL surgery.

EVIDENCE ACQUISITION

A Cochrane style search was performed and the following bibliographic databases were accessed: PubMed, Science Direct, Scopus, and Web of Science. This was carried out in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. All studies in the English language reporting on PCNL patients discharged within 24h were included.

EVIDENCE SYNTHESIS

Based on the literature search of 97 articles, nine (502 patients) met the inclusion criteria (mean age: 47 yr), with a mean stone size of 20.5mm. The mean operating time was 66min, and over a mean hospital stay of 17.5h, the stone-free rate was 95%. The overall complication rate was 13.5%; the vast majority of these complications were Clavien I-II complications, with a readmission rate of 3%.

CONCLUSIONS

Day-case PCNL is a safe and feasible strategy in carefully selected cases. However, for its success, detailed planning and adherence to surgical protocol are paramount with strict criteria for inpatient admission and a thorough follow-up plan.

PATIENT SUMMARY

Day-case percutaneous nephrolithotomy procedure seems to be a safe procedure with good outcomes, and low risk of complications and readmissions. Detailed preoperative protocol and planning are paramount, with indications for inpatient admission as well as a thorough follow-up plan.

Recent advances in understanding and managing urolithiasis

During the last few years, there has been relevant progress in both understanding and managing urolithiasis. Our knowledge of stone formation has changed; although the importance of urine biochemistry was questioned by several investigators years ago, the decisive role of cellular processes (induced by oxidative stress) and the renal papilla has only recently been generally accepted as the most important step in stone formation. For calcium oxalate urolithiasis, the formation of papillary calcifications plays a key role and is of prognostic relevance. Further research has to concentrate on these aspects of preventing urolithiasis. Stone prevention (metaphylaxis) is a major issue when considering the burden it places on healthcare systems. An effective metaphylaxis could lower the cost of stone therapy significantly. For uric acid urolithiasis, so far there is only preliminary information available showing that papillary plaques are not as important as they are in calcium oxalate urolithiasis. Concerning stone management, endourology has improved stone therapy significantly during the last few years. Morbidity decreased and success (stone-free) rates increased. Therefore, the indications for extracorporeal shockwave lithotripsy (ESWL) narrowed. ESWL, however, still has its place in stone therapy. There is not one single treatment modality that is equally effective for all situations. It is important to observe the differential indications for different stones depending on size, localization, and composition.