Postoperative sequelae of percutaneous nephrolithotomy

. Background. Risk factors of postoperative complications during percutaneous nephrolithotomy (PCNL) include stone burden, the preoperative microbiological status of urine, comorbidity, age, operative time, intraoperative level of sterility, and antibiotic prophylaxis. The study aimed to assess the sequelae of these complications. Materials and methods . This retrospective study was conducted on patients treated by PCNL under fluoroscopic guidance for a one-year duration. The demographic data, body mass index, stone burden, stone density, number, duration of surgery, and postoperative complications were recorded. Results . Out of 50 patients, 32 (64 %) developed a fever. White blood cell count was significantly high among those patients. The age of the patients, gender, body mass index, and hospital stay were insignificant variables. Stone burden, prolonged surgery duration, prone position during surgery, and the use of pneumatic lithotripsy were significant variables. Conclusions. Increased stone burden, prolonged duration of surgery, prone position, and pneumatic lithotripsy during PCNL are significant risk factors for developing postoperative complications, mainly fever.


Introduction
Percutaneous nephrolithotomy (PCNL) is the recommended management for renal stones > 2 cm.PCNL has significantly reduced morbidity and mortality, but infection and bleeding are still the most common complications [1].Other postoperative complications include a reduction in outflow leading to increase intra-renal pelvic pressure (IRP).Persistent high IRP leads to systemic fluid absorption, pyelo-tubular backflow, and forniceal rupture leading to stone and debris formation.In addition, debris and bacteria released from stone lead to bacteremia, postoperative fever, and septicemia [2].The incidence of post-PCNL sepsis is low (1 %), but the death rate is as high as 66 to 80 % [3].Clinically, maintaining an IRP of < 30 mmHg is acquired during percutaneous intra-renal techniques [4].

Materials and methods
In a clinical study conducted at the Department of Uro logy, among subjects have nephrolithiasis undergoing PCNL.Preoperatively patients were assessed and demographic parameters of the patients, history, and physical examination were documented.CT KUB or CT IVU was obtained for all.The stone burden was calculated (area).Investigations were done including urine culture sensiti vity.Individuals who have grown in the culture of urine were prescribed seven days of oral antibiotics.All the surgeries were performed by experienced urologists.All the procedures were done under spinal anesthesia.A prophylactic antibiotic (ceftriaxone 1 g) was given.A Foley catheter was inserted and the ureteral catheter was secured.The transpapillary puncture was done under fluoroscopic guidance.The stone was fragmented and removed by irrigation flow.The strategies include totally tubeless, or gold standard.Postoperatively, individuals were treated with IV fluids, antibiotics, and analgesics with a proton pump inhibitor.Patients were discharged after 72 hours or when they were clinically stable.Postoperative complications are categorized according to the modified Clavien-Dindo classification [5][6][7][8][9][10].Data analysis was done using the SPSS20 (IBM Corp., NY, USA).For baseline characteristics, we used the chi-square test or Fisher's exact test in categories and the t-test or Mann-Whitney U test for continuous data.A p-value < 0.05 was considered significant.

Results
A total of 50 patients were treated with PCNL.Male to female ratio was 2 : 1. IRP elevated more than 35 mmHg was seen in 40 (80 %) and 10 (20 %) had less than 35 mmHg.Mean age and mean BMI was found insignificant in the development of stone (Table 1 (PCNL) include stone burden, the preoperative microbiological status of urine, comorbidity, age, operative time, intraoperative level of sterility, and antibiotic prophylaxis.The study aimed to assess the sequelae of these complications.Materials and methods.This retrospective study was conducted on patients treated by PCNL under fluoroscopic guidance for a one-year duration.The demographic data, body mass index, stone burden, stone density, number, duration of surgery, and postoperative complications were recorded.Results.Out of 50 patients, 32 (64 %) developed a fever.White blood cell count was significantly high among those patients.The age of the patients, gender, body mass index, and hospital stay were insignificant variables.Stone burden, prolonged surgery duration, prone position during surgery, and the use of pneumatic lithotripsy were significant variables.Conclusions.Increased stone burden, prolonged duration of surgery, prone position, and pneumatic lithotripsy during PCNL are significant risk factors for developing postoperative complications, mainly fever.Vol. 12, No. 3, 2023

Оригінальні статті / Original Articles
The majority of the patients underwent mini-PCNL (n = 45) and hence there was no significant difference.A total of 44 patients underwent PCNL by using pneumatic lithotripsy and the remaining 6 underwent PCNL using shock pulse.A significantly high number of patients (n = 37) patients in the prone position had raised IRP > 35 mmHg.Thirty-two patients developed postoperative fever (Fig. 1).As depicted in Table 2, GI complications, according to Clavien-Dindo classification, were found in 68 %, GII in 24 %, and 8 % had GIII.However, no grade IV was recorded.

Discussion
With the dramatic raising in stone disease occurrences, the use of PCNL to manage a large stone has continued to rise [11].The success of stone surgery is measured by the duration of surgery, stone-free rate, hospital stay, complications, and cost-effective.Infectious after PCNL are most common and bacteremia is the most of the cases determined.Although these lead to sepsis are rare, which potentially end with life-threatening outcomes [12].
During PCNL, continuous pressurized irrigation is used to washout blood clots and debris for active removal of the stone fragments after lithotripsy [13,14].
There are different studies documented post-PCNL high-grade fever, the incidence ranged between 10 to 32 %.In this work, a postoperative fever was recorded in 32 cases.The high rate of fever was reported by Gutierrez et al. [3] and Troxel and Low [15].
In one randomized single-blind trial by Omar et al.
[16] randomized cases that high-pressure irrigation elevated the risk of complications.GIV 0 0

Figure 1. A -types of PCNL, B -types of lithotripsy, C -patients' position, D -accompanied fever
Оригінальні статті / Original Articles Troxel with Low [15] measured IRP using a ureteral occlusion balloon catheter and a urodynamic system.In contrast, they did not record any association of IRP 30 mmHg or greater with postoperative fevers [15,16].Cheng Wu et al.
[17] found a significant association between higher IRP and increased incidence of postoperative fever where 43.83 % (100/228) patients had IRP > 30 mmHg and 28 patients developed a fever.They analyzed that the longer accumulated period of IRP > 30 mmHg for > 60 sec predicted the fever.
The female sex is recognized to be a risk for post-PCNL fever development [18].In this study, male to female ratio was 2 : 1 among raised IRP group and was not a risk for developing a fever.
A comparative study of mini-PCNL and standard PCNL by Zhong Wen et al. [20] and Cheng Wu et al. [17] showed that mini-PCNL was correlated with higher IRP and significantly associated with postoperative fever.In this study the majority of cases were mini-PCNL and we could not find statistical significance among them.
Liangren Liu et al. [18] in their systematic review and meta-analysis including 389 patients found that PCNL in the supine position spends a shorter time than the prone, but both situations have insignificant influence.Falahatkar et al. [21] mentioned in their prospective analytical crosssectional study, fever was associated with 7.5 % (25/330) which was not found significant.The patients with supine, access sheath remains angled horizontally when compared with prone, which falls pressure in the collecting system that facilitates the stone fragments to get out through the sheath.
This study was done in only one center within a short period and with a relatively small patient number.This study failed to compare mini PCNL and standard PCNL and different energy sources on postoperative fever due to disparity in the number of cases.
An elevated stone development and burden correlated with long surgery time, the position of the patient during the operation, and lithotripsy types.Postoperative complications including fever and bleeding most common after percutaneous nephrolithotomy, however, it has significantly dropped morbidity and mortality.
Limitations of the study.This study was done in only one center within a short period and with a relatively small patient number.This study failed to compare mini PCNL and standard PCNL and different energy sources on postoperative fever due to disparity in the number of cases.

Conclusions
An increased stone burden, prolonged duration of surgery, prone position, and pneumatic lithotripsy during PCNL represent a significant risk for postoperative infective complications development especially fever.Vol. 12, No. ).