Toward Respiratory-Gated Retrograde Intrarenal Surgery: A Prospective Controlled Randomized Study

Comparing Same-Sitting Bilateral vs Unilateral Retrograde Intrarenal Surgery in the Elderly

OBJECTIVE

To compare same-sitting bilateral vs unilateral retrograde intrarenal surgery (RIRS) in elderly patients, focusing on postoperative complications and stone-free rates (SFR).

METHODS

Data from 2 multicenter databases, FLEXible ureteroscopy Outcomes Registry (FLEXOR) (unilateral RIRS) and same sitting bilateral-retrograde intrarenal surgery (SSB-RIRS) (bilateral RIRS), were analyzed, considering only patients aged 70+ with preoperative computed tomography. Patients were categorized into Group 1 (bilateral RIRS) and Group 2 (unilateral RIRS). Follow-up included imaging assessments and secondary treatments as needed.

RESULTS

Group 1 included 146 patients, while group 2 had 495. Group 1's patients were slightly older and had a higher prevalence of recurrent stone formation. Group 2 often underwent RIRS for incidental stones. Group 1 had larger and more pelvic stones. Laser lithotripsy and total operation times were significantly longer in Group 1. Group 2 had significantly higher overall stone-free rates, although there were no significant differences in ancillary procedures for residual fragments. Group 1 experienced more pelvicalyceal injuries needing stenting, postoperative fever, and post-op hematuria not requiring transfusion.

CONCLUSION

In conclusion, bilateral RIRS can be carefully considered in elderly patients. Preoperative counseling is essential for both primary and repeat RIRS procedures, and further research is needed to optimize instrument and laser strategies for better outcomes in elderly RIRS patients.

Querying the significance of patient position during computerized tomography on the reliability of pre-percutaneous nephrolithotomy planning

BACKGROUND

Computerized tomography (CT) is considered indispensable in percutaneous nephrolithotomy (PCNL) planning. We aimed to define the reliability of pre-PCNL CT for planning renal access by assessing renal positional changes between supine and prone CTs.

SUBJECTS AND METHODS

CT urographies (CTU) of 30 consecutive patients were reviewed for distances upper pole (UP)-diaphragm, UP-diaphragm attachment, renal pelvis (RP)-lateral body wall, RP- posterior body wall, and lower pole (LP)- anterior-superior iliac spine (ASIS). The posterior and lateral renal axes angles were also calculated.

RESULTS

The most consistent overall movement in transition from prone to supine was backward rotation, as demonstrated by a decrease in distance UP-posterior body wall (p = 0.010) and increase in the posterior renal angle (p < 0.0001). This finding correlated with the patient's body mass index (BMI) (p = 0.029). The left kidney was more mobile than the right one, moving significantly for five of the measured parameters compared to the right kidney which moved significantly for only two parameters. The UP-diaphragm distance of the left kidney correlated with age (p = 0.014), the RP-lateral wall distance correlated with previous abdominal surgery (p = 0.006), and the RP-posterior wall distance with BMI (p = 0.017). On the right, the UP-diaphragm distance correlated with gender (p = 0.002) and the lateral renal rotation was smaller (p = 0.046).

CONCLUSIONS

Kidneys present significant mobility between supine and prone positions. CT assessment should be performed in the position expected during surgery and should be interpreted with caution, while a real-time imaging modality should be used in the operating room.

Flexible ureterorenoscopy and laser lithotripsy with regional anesthesia vs general anesthesia: A prospective randomized study

Purpose

To compare the effect of general anesthesia (GA) and regional anesthesia (RA) on f-URS outcomes and surgeon comfort.

Material and Methods

The study was conducted between June 2017 to January 2018 and data collection was applied in a prospective, randomized fashion. 120 patients participated in the study and were divided into RA group (n=56) and GA group (n=64). Demographic, operative and post-operative parameters of patients were analysed. The end point of this study was the effect of two anesthesia regimens on the comfort of the surgeon, and the comparability of feasibility and safety against perioperative complications.

Results

The study including 120 randomized patients, 14 patients were excluded from the study and completed with 106 patients (45 in RA group and 61 in GA group). No difference was detected between the two groups in terms of preoperative data. During the monitorization of operative vital signs, 3 patients in RA group experienced bradycardia, and this finding was significant when compared with GA group (p=0.041). Additionally, 2 patients in RA group experienced mucosal tears and 1 patient experienced hemorrhage during the operation, but no complications were observed in the GA group (p=0.041). Postoperative surgeon comfort evaluation revealed statistically significant results in favor of GA group (p=0.001).

Conclusions

Both GA and RA are equally effective and safe anesthesia methods for f-URS procedures. However, RA group showed significantly increased likelihood of bradycardia and mucosal injury during surgery, and significantly decreased surgeon comfort during surgery.

Reducing kidney motion: optimizing anesthesia and combining respiratory support for retrograde intrarenal surgery: a pilot study

BACKGROUND

One of the greatest challenges presented with RIRS is the potential for movement of the stone within the operative field associated with diaphragm and chest respiratory excursions due to mechanical ventilation. To overcome this challenge, we propose in this pilot study a new general anesthesia technique combining high frequency jet ventilation (HFJV) with small volume mechanical ventilation (SVMV). Data regarding safety, feasibility and surgeons' impression was assessed.

METHODS

Patients undergoing RIRS for kidney stones from November 2017 to May 2018 were prospectively recruited to participate in the study. In each case after the beginning of general anesthesia (GA) with mechanical ventilation (MV) surgeons were asked to assess the mobility of the operative field and conditions for laser lithotripsy according to the developed questionnaire scale. The questionnaire consisted of 5 degrees of assessment of kidney mobility and each question was scored from 1 to 5, 1 being very mobile (extremely poor conditions for dusting) and 5 completely immobile (Ideal conditions for dusting). After the assessment GA was modified with combined respiratory support (CRS), reducing tidal volume and respiratory rate (small volume mechanical ventilation, SVMV) and applying in the same time transcatheter high frequency jet ventilation (HFJV) inside the closed circuit. After beginning of CRS, surgeons were once again asked to assess the mobility of the operative field and the conditions for laser lithotripsy. Main ventilation parameters were recorded and compared in both regimens.

RESULTS

A total of 38 patients were included in the study. The mean age was 49 (range 45-53) with a mean stone size of 10 mm (range 10-14) and Hounsfield unit of 1060 (range 930-1190). All patients underwent successful RIRS and no intraoperative complications occurred throughout the duration of the study. A statistically significant difference between ventilation parameters prior to and after CRS institution was detected in all cases, however their clinical impact was negligible. Despite this, assessment via the questionnaire scale point values varied significantly before and after the application of CRS and were 2.3 (2.1; 2.6) and 3.8 (3.7; 4.0) respectively (p < 0.001).

CONCLUSIONS

The novel combined respiratory approach consisting of HFJV and SVMV appears to provide better conditions for stone dusting through reduced respiratory kidney motion and is not associated with adverse health effects or complications.

TRIAL REGISTRATION

NCT03999255 , date of registration: 25th June 2019 (retrospectively registered).