Does body mass index effect the success of percutaneous nephrolithotomy?

Ultrasound-guided percutaneous nephrolithotomy (PCNL) success rates in patients with elevated body mass index: a comparative study

Percutaneous nephrolithotomy (PCNL) is considered gold standard treatment of renal stones larger than 20 mm. Several studies have shown that ultrasound guidance during this procedure is more effective and safer than fluoroscopy. A higher body mass index (BMI) can make ultrasound-guided renal access more difficult and unsuccessful. We present a prospective analysis and comparison of ultrasound-guided PCNL in patients with normal and increased body mass index. We performed a prospective comparison of patients who underwent ultrasound-guided PCNL to remove renal stones by a single surgeon between 2020 and 2022. Patients with BMIs greater than 30 (mean 33.87-obese) were compared to those with BMIs less than 30 (mean 25.69-non-obese). Demographic, perioperative, and follow-up data were collected, analyzed, and included in this study. Total of 98 consecutive patients, with 49 patients in each group were analyzed. No statistically significant differences were observed in terms of stone volume (P = 0.085), stone density (P = 0.5590), location of renal access (P = 0.108), surgery duration (P = 0.38), blood loss (P = 0.54), or laboratory changes after surgery (P = 0.60). 87.76% of obese patients were stone free per CT scan at follow-up, compared to 73.47% of normal-weight patients (P = 0.1238). According to Clavien-Dindo classification, six patients in the non-obese group experienced grade II (10%) and grade III (2%) complications, as opposed to six patients in the obese group with grade I (2%), grade II (6%), and grade III (2%) complications. There was no significant correlation between body mass index and the success or safety of ultrasound-guided PCNL. Although more challenging, a higher BMI should not be an impediment to performing this approach. This method is safe, with no increased incidence of postoperative complications or compromise in stone-free status postoperatively and can diminish or avoid both patient's and medical team's exposure to ionizing radiation.

Effect of Body Mass Index on Outcomes of Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis

Objective

The current study aimed to assess the efficacy and safety of percutaneous nephrolithotomy (PCNL) in obese and overweight individuals based on body mass index (BMI).

Methods

We electronically explored the databases of PubMed, CENTRAL, ScienceDirect, Embase, and Google Scholar databases for all types of comparative studies investigating the role of BMI on PCNL outcomes. Only studies defining obesity as >30 kg/m² were included. Efficacy outcomes were stone-free rates and operating time while safety outcomes were complications and length of hospital stay (LOS).

Results

Eighteen studies with 101,363 patients were included. We noted no difference in the stone-free rates after PCNL for morbid obese vs normal BMI patients (OR: 0.78 95% CI, 0.57, 1.08 I²= 7% p = 0.13), overweight vs normal (OR: 1.01 95% CI, 0.89, 1.15 I²= 1% p = 0.83) and obese vs normal patients (OR: 1.00 95% CI, 0.87, 1.16 I²= 0% p = 0.95). PCNL operative time was significantly increased in morbid obese (MD: 9.36 95% CI, 2.85, 15.88 I²= 76% p = 0.005) and obese patients as compared with normal patients (MD: 2.15 95% CI, 1.20, 3.10 I²= 0% p < 0.00001), but not for overweight patients. There was no difference in the odds of complications between morbid obese vs normal (OR: 1.26 95% CI, 0.93, 1.72 I²= 0% p = 0.13), overweight vs normal (OR: 1.11 95% CI, 0.96, 1.28 I²= 0% p = 0.15), and obese vs normal patients (OR: 1.07 95% CI, 0.91, 1.27 I²= 0% p = 0.40). LOS was significantly reduced in obese patients (MD: −0.12 95% CI, −0.20, −0.04 I²= 0% p = 0.004) as compared to normal patients, but not for morbid obese or overweight patients.

Conclusion

PCNL has similar efficacy and safety in morbidly obese, obese, and overweight patients as compared to normal BMI patients with no difference in the stone-free and complication rates. Evidence suggests that operating time is increased in morbidly obese and obese patients and the latter may have shorter LOS.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/, identifier: CRD42022313599.

Percutaneous nephrolithotomy outcomes based on body mass index: A 5-year retrospective study in an Indonesian tertiary hospital

Objectives:

The aim of this study was to evaluate the impact of body mass index (BMI) on percutaneous nephrolithotomy (PCNL) outcomes and complications for nephrolithiasis.

Patients and methods:

Patients with a history of PCNL surgery from 2012 to 2017 in Dr. Soetomo General-Academic Hospital were retrospectively evaluated. Patients were then categorized into four groups: underweight (BMI <18.5 kg/m2), normal (BMI 18.5 to 24.99 kg/m2), overweight (BMI ⩾25–29.9 kg/m2), and obese (BMI ⩾30 kg/m2). The association between BMI, subjects’ characteristics, length of stay, stone-free rate (SFR), and complications were analyzed using one-way analysis of variance (ANOVA) and univariate logistic regression.

Results:

The study included 430 male patients (58%) and 310 female patients (42%). They were classified based on their BMI into underweight ( n = 5, 1%), normal weight ( n = 291, 39%), overweight ( n = 271, 37%), and obese ( n = 173, 23%) groups. The underweight BMI group had a higher average blood loss ( p=0.002) compared to the other groups; however, the univariate logistic regression showed that BMI had no significant effect on SFR ( p=0.491).

Conclusion:

PCNL is safe and feasible to be performed in patients with different BMI as obesity has no impact on the outcomes and complications associated with PCNL.

Level of evidence

3

Does body mass index impact the efficacy and complication rate of mini-percutaneous nephrolithotomy?

Aim:

This was a retrospective cohort study exploring the efficacy of mini-percutaneous nephrolithotomy in obese patients and whether stone clearance, complication rate and length of stay is impacted by an increasing body mass index.

Method:

Data was collected retrospectively for all mini-percutaneous nephrolithotomies performed at a single centre over a 21-month period commencing March 2017. The primary outcomes included length of stay, stone clearance rates and complications.

Results:

Fifty-eight percutaneous nephrolithotomies were undertaken during the study period and of these cases 81% of patients had a body mass index of 25 or greater. The stone clearance rate was 83%. However, severely obese patients were noted to have a lower stone clearance rate. No complications occurred in the normal body mass index cohort. However, there was no difference in the complication rate for the remaining groups. Post-operative stay was approximately 3 days.

Conclusion:

This study demonstrates that supine mini-percutaneous nephrolithotomies are a safe option in obese patients with no increased risk of serious complication. Whilst stone clearance rates were lower in the severely obese category, clearance was complete in the majority of cases.

Level of evidence:

3

Obesity and its implications on nononcological urological surgery

PURPOSE OF REVIEW

To review and summarize the current literature of the implications of obesity on nononcological urological surgery. We conducted a comprehensive search of the current literature with emphasis on the published literature in the last 18 months.

RECENT FINDINGS

Over time, obese patients have become a more common encounter in clinical practice. Obesity represents a considerable operative challenge and has been linked to a higher rate of postoperative complications. Data regarding surgery for incontinence are inconsistent. Nevertheless, the success rates in obese women are high, and complication rates are relatively low with comparable results to nonobese women. In renal surgery, percutaneous nephrolithotomy and minipercutaneous nephrolithotomy are feasible, well tolerated, and effective even in obese patients. However, certain precautions and availability of proper instruments are necessary.

SUMMARY

Although randomized clinical data are lacking and the results of many studies are inconsistent, evidence supports the feasibility and safety of different nononcological urological interventions in obese patients. Moreover, the success rates and the overall complication rates seem to be comparable to nonobese patients with some exceptions.

Efficacy and safety of mini percutaneous nephrolithotomy in obese patients

Purpose

We aimed to evaluate the effect of obesity on surgical outcomes of mini percutaneous nephrolithotomy (Mini-PNL).

Methods

Hundred and eighty two Mini-PNL procedures were performed between May 2013 and January 2015 and their results were evaluated retrospectively. Patients were classified as non-obese (BMI, 18.5–30 kg/m²) and obese (≥30 kg/m²) groups. Obese and non-obese patients were compared according to pre-operative demographic values, intra-operative surgery techniques and post-operative results.

Results

BMI values of 133 patients were lower than 30 kg/m² while 49 patient’s BMI values were higher than 30 kg/m². There were no significant difference between operation time, fluoroscopy time, number of access and access sites when two groups were compared. No significant difference was found in total length of hospital stay, hemoglobin drop, and complication rates. Stone-free rates were 70.7 % in the non-obese and 71.4 % in the obese group (p = 0.9).

Conclusions

Mini-PNL procedure is a safe and effective treatment modality, which should be strongly considered for obese patients with appropriate sized stones.