Analysis of the factors affecting blood loss in percutaneous nephrolithotomy: a registry of the Spanish Association of Urology in the supine position

Risk Factors for Intra-operative Bleeding in Percutaneous Nephrolithotomy in an Academic Center: A Retrospective Study

Background

Percutaneous nephrolithotomy (PNL) is the treatment of choice for renal stones as a safe, effective, and minimally invasive method. However, bleeding remains a major concern in the procedure.

Objectives

This study aimed to investigate the risk factors of bleeding in PNL.

Methods

This retrospective descriptive cross-sectional study was conducted in the Urology department of Razi hospital. The data of patients with urinary calculi staghorn type who underwent PNL in a prone position under general anesthesia were recorded. A checklist including patients' demographics, surgical characteristics, and outcomes was filled out for each patient.

Results

The data from 151 complete files were gathered. The mean age of the cases was 47.89 ± 12.41 years. The mean hemoglobin (Hb) drop was 1.92 ± 1.56 mg/dL. At least 1 mg/dL Hb drop was observed in all cases. The highest Hb drop was 3 mg/dL.). There was no significant relationship between stone bulk, age, BMI, GFR, surgery duration, and the number of tracts, and Hb drop during PNL (P > 0.05). But there was a positive correlation between Urinary Tract Infection (UTI) history (P = 0.01) and transfusion (P = 0.0001) and Hb drop during PNL. Also, the history of open kidney surgery (P = 0.031), nephrostomy insertion (P = 0.003), and extracorporeal shock wave lithotripsy therapy (ESWL) (P = 0.041) were correlated with the increased risk of Hb drop.

Conclusions

Urinary tract infection, history of open surgery, nephrostomy implantation, and ESWL were significantly associated with more bleeding in PNL.

Endoscopic combined intrarenal surgery (ECIRS) - Tips and tricks to improve outcomes: A systematic review

OBJECTIVE

This study aimed at assessing current efficacy and safety of endoscopic combined intrarenal surgery (ECIRS) for the treatment of large and/or complex urolithiasis and identifying relevant tips and tricks able to improve its outcomes, mainly deriving from the adjunct of retrograde flexible ureteroscopy to the traditional antegrade approach of percutaneous nephrolithotomy (PNL).

MATERIAL AND METHODS

A systematic review was conducted using relevant databases (Ovid Medline, PubMed, Scopus, and Web of Sciences), employing "ECIRS" as the search term in all cases, and then adding "endoscopic combined intrarenal surgery" and "flexible ureteroscopy AND percutaneous nephrolithotomy" as search terms for PubMed and Scopus. Original articles and systematic reviews were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Additionally, the reference lists of the selected publications were checked manually.

RESULTS

A total of 14 studies were selected for analysis: two systematic reviews, one randomized controlled trial, five nonrandomized comparative studies, three prospective case series, and three retrospective case series. ECIRS achieves high stone-free rates and rather low/low Clavien-Dindo grade complication rates, confirming the role of retrograde ureteroscopy in the maximization of its efficacy and safety. A narrative synthesis of the most recognized tips and tricks of ECIRS is provided.

CONCLUSION

The contribution of retrograde flexible ureteroscopy during PNL is essential. It plays a dual role, both diagnostic and active, allowing tailoring of the procedure to the patient, urolithiasis, and anatomy of the collecting system and optimization of the PNL efficacy and safety. This is ECIRS: an updated, complete, and versatile version of PNL.

Techniques - Ultrasound-guided percutaneous nephrolithotomy: How we do it

Ultrasonography has emerged as an alternative to fluoroscopy for image-guided percutaneous nephrolithotomy (PCNL) in many countries. Compared to fluoroscopy-guided PCNL (F-PCNL), ultrasound-guided PCNL (US-PCNL) is easier to learn and reduces radiation exposure to patients and providers. Despite these advantages, uptake of ultrasound-guided PCNL (US-PCNL) in Canada has been almost nonexistent, largely because it is not incorporated into urologists' training. In this article, we seek to familiarize Canadian urologists with this approach by describing our step-by-step technique for US-PCNL. Additionally, we provide keys to successful implementation of this technique.

Updates in endourological management of urolithiasis

Urinary stone disease, or urolithiasis, is a very common disease with increasing prevalence and incidence. With the advancement of endoscopic techniques, the treatment outcomes of ureteroscopy (or transureteral lithotripsy) and percutaneous nephrolithotomy are continuously improving. In recent years, there have been many new developments in the field, including new endoscopy design, more effective auxiliary tools, improvement in treatment protocols, introduction of robotic technology, combining both ureteroscopy and percutaneous nephrolithotomy (endoscopic combined intrarenal surgery or transureteral lithotripsy-assisted percutaneous nephrolithotomy), improvement in laser technology, and so on. All these new inputs will further improve the treatment efficacy and safety of the procedures, thus benefiting our patients. In the present review, we briefly go through the main steps of ureteroscopy and percutaneous nephrolithotomy, with a concise description and application of these new advances.

Percutaneous Nephrolithotomy with Amplatz and Alken Dilators: An Eight-Year Single Tertiary Care Centre Experience

Background

Percutaneous nephrolithotomy (PNL) is the standard procedure for patients with renal stones over 2 cm in diameter. We analyzed complications after this procedure focusing on two different methods of tract dilation.

Material/Methods

Between August 2008 and April 2016 222 percutaneous nephrolithotomies were performed in a total of 208 patients. The Group I (n=123) comprised patients where Alken dilatators were used, while Group II (n=99) comprised patients where Amplatz dilators were used. Efficacy was examined based on ultrasound and x-ray examination one month after the procedure. Complications were recorded using Clavien Dindo classification.

Results

Efficacy was 85.3% and 86.8% in group I and II, respectively (p=0.77). Grade I complications were present in 14.6% and 3%, grade II were present in 9.7% and 8%, grade IIIa were present in 2.4% and 2%, grade IIIb were present in 1.6% and 2%, grade IVa were present in 1.6% and 7%, grade IVb were present in 3.2% and 1% in Group I and Group II, respectively. These differences were statistically significant (p=0.03).

Conclusions

Efficacy was comparable between Alken dilator and Amplatz dilator groups. In group I, there were more postoperative fevers >38.5 °C and a higher rate of urosepsis. On the other hand, in group II we observed more pleural injuries. All differences resulted from the type of access to the kidney (inter/infracostal), punctured calyx, and utilization (or not) of access sheath rather than type of dilators itself.

Miniperc and retrograde intrarenal surgery: when and how?

CONTEXT

Extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL) are consolidated procedures for the treatment of kidney stones; however, their primary weak points are the lower efficacy of ESWL, especially for lower calyx stones, and the morbidity of PCNL resulting from the creation and dilation of the percutaneous trajectory. The increasing miniaturization of percutaneous surgery instrumentation and the development of retrograde intrarenal surgery (RIRS) are recent innovations.

ACQUISITION OF EVIDENCE

A structured nonsystematic review was conducted through a literature search of articles published between 1997 and 2013, using the terms kidney stones, miniperc, mini-PCNL, RIRS and flexible ureteroscopy in the PubMed, Google Scholar and Scopus databases.

SUMMARY OF THE EVIDENCE

RIRS requires greater surgical time, several procedures for voluminous stones and higher hospital costs, due in part to the relative fragility of the instruments. On the other hand, miniperc requires a longer hospital stay, an increased need for postoperative analgesia and a greater reduction in hemoglobin levels, although these do not translate into an increased rate of transfusions.

CONCLUSIONS

The current treatment of kidney stones uses minimally invasive procedures such as miniperc and RIRS. The 2 procedures are equivalent in terms of efficacy (stone clearance) and are associated with minimal complications. Comparative prospective studies are necessary to determine the position of each of these techniques in the treatment of kidney stones. In our experience, the 2 techniques are complementary and should be part of the current urological therapeutic arsenal.

Comparative study of retrograde intrarenal surgery and micropercutaneous nephrolithotomy in the treatment of intermediate-sized kidney stones

OBJECTIVE

Retrograde intrarenal surgery (RIRS) has proven efficacy with minimal morbidity in the treatment of intermediate-sized kidney stones. The aim of this study was to examine the feasibility of micropercutaneous nephrolithotomy (microperc) for this indication and evaluate its results compared with those of RIRS.

MATERIAL AND METHODS

From September to December 2013, we performed a comparative prospective study between RIRS and microperc, with 20 consecutive patients with intermediate-sized (1-3cm) kidney stones. We employed a flexible dual-channel ureteroscope (Cobra, Richard Wolf GmbH) and a Microperc 4.85/8 Fr (with the patient supine) with flexible fiberoptics (0.9mm, 120° and 10,000 pixels) (PolyDiagnost GmbH). The study variables were demographic data, stone characteristics, percentage of stone elimination, complications (Clavien-Dindo), surgical time, hospital stay and need for auxiliary procedures.

RESULTS

The patients underwent RIRS (n=12) or microperc (n=8). There were no differences in the demographics or stone characteristics between the 2 groups. The percentage of stone elimination with RIRS and microperc was 91.7% and 87.5% (P=1), respectively. One of the patients who underwent RIRS (8.3%) experienced postoperative fever; one of the patients who underwent microperc (12.5%) experienced postoperative colic pain (both cases were classified as Clavien I). The operative times were similar: 120min (111.2-148.7) and 120 (88.7-167.5) min for RIRS and microperc (P=.8), respectively. None of the patients required a blood transfusion. The hospital stays were also equivalent: 1 day (1-2) and 1.5 days (1-3.5) for RIRS and microperc (P=.33), respectively. Two patients treated with microperc (25%) required auxiliary procedures (simultaneous RIRS and flexible nephroscopy after percutaneous trajectory dilation to treat, in both cases, a significant fragment that had migrated to an inaccessible calyx), and 1 patient in the RIRS group (8.3%) required percutaneous nephrolithotomy due to unfavorable infundibular-calyceal anatomy (P=.54).

CONCLUSIONS

Microperc is a minimally invasive method that is emerging as an effective and safe treatment for intermediate-sized kidney stones. Studies are needed to better evaluate its cost-effectiveness, the need for complementary treatments and its possible complementarity with RIRS when working with patients in the supine position.

Comparative study of retrograde intrarenal surgery and micropercutaneous nephrolithotomy in the treatment of intermediate-sized kidney stones

OBJECTIVE

Retrograde intrarenal surgery (RIRS) has proven efficacy with minimal morbidity in the treatment of intermediate-sized kidney stones. The aim of this study was to examine the feasibility of micropercutaneous nephrolithotomy (microperc) for this indication and evaluate its results compared with those of RIRS.

MATERIAL AND METHODS

From September to December 2013, we performed a comparative prospective study between RIRS and microperc, with 20 consecutive patients with intermediate-sized (1-3cm) kidney stones. We employed a flexible dual-channel ureteroscope (Cobra, Richard Wolf GmbH) and a Microperc 4.85/8 Fr (with the patient supine) with flexible fiberoptics (0.9mm, 120° and 10,000 pixels) (PolyDiagnost GmbH). The study variables were demographic data, stone characteristics, percentage of stone elimination, complications (Clavien-Dindo), surgical time, hospital stay and need for auxiliary procedures.

RESULTS

The patients underwent RIRS (n=12) or microperc (n=8). There were no differences in the demographics or stone characteristics between the 2 groups. The percentage of stone elimination with RIRS and microperc was 91.7% and 87.5% (P=1), respectively. One of the patients who underwent RIRS (8.3%) experienced postoperative fever; one of the patients who underwent microperc (12.5%) experienced postoperative colic pain (both cases were classified as Clavien I). The operative times were similar: 120min (111.2-148.7) and 120 (88.7-167.5) min for RIRS and microperc (P=.8), respectively. None of the patients required a blood transfusion. The hospital stays were also equivalent: 1 day (1-2) and 1.5 days (1-3.5) for RIRS and microperc (P=.33), respectively. Two patients treated with microperc (25%) required auxiliary procedures (simultaneous RIRS and flexible nephroscopy after percutaneous trajectory dilation to treat, in both cases, a significant fragment that had migrated to an inaccessible calyx), and 1 patient in the RIRS group (8.3%) required percutaneous nephrolithotomy due to unfavorable infundibular-calyceal anatomy (P=.54).

CONCLUSIONS

Microperc is a minimally invasive method that is emerging as an effective and safe treatment for intermediate-sized kidney stones. Studies are needed to better evaluate its cost-effectiveness, the need for complementary treatments and its possible complementarity with RIRS when working with patients in the supine position.

A comparative study of percutaneous nephrolithotomy in supine position and endoscopic combined intrarenal surgery with flexible instrument

OBJECTIVE

To compare the results obtained in percutaneous nephrolithotomy after introduction of flexible ureteroscopy/nephroscopy (endoscopic combined intrarenal surgery - ECIRS) with nephrolitomies with only rigid nephroscopy (standard percutaneous nephrolithotomy; sPCNL).

MATERIAL AND METHOD

A retrospective study of 171 sPCNL in Galdakao position performed between January 2005 and December 2011 was conducted. We compared the results obtained in those procedures in which endoscopic combined intrarenal surgery (ECIRS) was performed with those in which only the rigid nephroscopy (sPCNL) was used. Specific and global success, percentage of lithiasic load eliminated, days of hospital stay and complications derived were calculated. We defined success by complete absence of lithiasis or residual presence of<5mm. We differentiated specific success, that only achieved with percutaneous surgery, from global success, or that achieved after a second line of treatment.

RESULTS

In 73 procedures (42.4%) ECIRS was performed with flexible endoscopy while in 98 (57.6%) it was done with sPCNL. Both groups were comparable in regards to demographic parameters and characteristics of the lithiasis. The success rates in the first procedure and global success were superior for the ECIRS group (75.3% vs 40.8% and 93.1% vs 74.5%), the differences being statistically significant (P<.05). No statistically significant differences were found in regards to the complications (28.8% vs 28.3% P=.86) or days of hospital stay (4.5 vs 5.0 P=.18).

CONCLUSIONS

Use of the flexible ureteroscopy/nephroscopy in sPCNL (ECIRS) improves the success rates and elimination of lithiasic load, making it possible to perform the surgery with a single access in most of the cases.