Relevance of intravesical pressures during transurethral procedures

Does sheath size matter: benchtop comparison of flow and pressure across variety of continuous flow endoscopes

INTRODUCTION

Laser enucleation utilizes purpose-built endoscopes for laser stabilization and continuous flow. No evaluation has been done with respect to flow or intravesical pressure with these scopes. We sought to evaluate the effect different endoscopes and sheath sizes on irrigation outflow and intravesical pressure.

METHODS

Using a benchtop model using a silicone bladder model, five outer/inner sheath combinations were assessed: Storz 28/26Fr, Storz 26/26Fr, Wolf 26/24Fr, Wolf 26/22Fr, and Wolf 24/22Fr. A urodynamics pressure transducer was inserted alongside the scope for bladder pressure measurement and outflow from scope to drain was measured using uroflowmetry device. Four 1-minute trials were recorded for each sheath and the steady state flow and pressure was recorded.

RESULTS

The Storz 28 F outer sheath and 26 F inner sheath had the highest outflow (12.4 ± 0.5 mL/s, p < 0.01). The Wolf 24 F outer and 22 F inner had the lowest outflow (7.0 ± 0.0 mL/s, p < 0.01). The steady state bladder pressure was the lowest in the Storz 28/26 (1.5 ± 1.7 cm H2O, p < 0.01)) and the greatest in the Storz 26/26 (24.2 ± 1.9 cm H2O, p < 0.01).

CONCLUSION

The Storz 28/26 combination had best outflow rate and lowest intravesical pressures in our benchtop study. Flow rates generally decreased with smaller sheath sizes and steady state bladder pressures increased as the difference between the outflow and inflow sheath size narrowed. These findings provide initial parameters that could guide sheath selection in future to optimize visualization and success of voiding trials.

Evaluating the efficacy and safety of Holmium laser enucleation of the prostate in patients with obstructive uropathy attributable to bladder outlet obstruction

OBJECTIVE

To evaluate outcomes of Holmium laser enucleation of the prostate (HoLEP) in individuals presenting with obstructive-uropathy (OU) attributable to bladder outlet obstruction (BOO).

METHODS

We performed a retrospective review of patients who underwent HoLEP from August 2017 to January 2023 at our institution. We identified patients with preoperative OU defined by presence of chronic hydronephrosis suggestive of BOO and conducted a matched-pair analysis (1:2) with patients undergoing HoLEP without OU. Patients' demographic, perioperative and postoperative voiding parameters, serum creatinine level, and complications were analyzed up to one-year of follow-up.

RESULTS

Preoperative OU was present in 42 patients. Demographic and preoperative parameters were comparable except median preoperative creatinine (1.245 vs. 1.065 ng/ml, p < 0.001) and catheterization rates (76.2% vs. 25%, p < 0.001) were higher in the OU group. The mean duration of postoperative catheterization was longer in the OU group (3.83 vs. 2.26 days, p = 0.048). Two patients in the OU group developed postoperative acute kidney injury. There was no difference in the rate of postoperative complications, improvement in International Prostate Symptom Score and maximum urinary flow amongst both groups except a higher post-void residual volume at 3- and 12-months (p = 0.001 and p = 0.037, respectively) in OU patients. Patients noted significant improvement in serum creatinine level at 6-12 weeks postoperatively from peak baseline level (P = 0.002).

CONCLUSION

HoLEP is effective and safe in patients with OU suggestive of BOO, though they are at higher risk of postoperative acute kidney injury.

Experts' recommendations in laser use for the treatment of bladder cancer: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training and Research in Urological Surgery and Technology (TRUST)-Group

PURPOSE

To identify laser settings and limits applied by experts during laser vaporization (vapBT) and laser en-bloc resection of bladder tumors (ERBT) and to identify preventive measures to reduce complications.

METHODS

After a focused literature search to identify relevant questions, we conducted a survey (57 questions) which was sent to laser experts. The expert selection was based on clinical experience and scientific contribution. Participants were asked for used laser types, typical laser settings during specific scenarios, and preventive measures applied during surgery. Settings for a maximum of 2 different lasers for each scenario were possible. Responses and settings were compared among the reported laser types.

RESULTS

Twenty-three of 29 (79.3%) invited experts completed the survey. Thulium fiber laser (TFL) is the most common laser (57%), followed by Holmium:Yttrium-Aluminium-Garnet (Ho:YAG) (48%), continuous wave (cw) Thulium:Yttrium-Aluminium-Garnet (Tm:YAG) (26%), and pulsed Tm:YAG (13%). Experts prefer ERBT (91.3%) to vapBT (8.7%); however, relevant limitations such as tumor size, number, and anatomical tumor location exist. Laser settings were generally comparable; however, we could find significant differences between the laser sources for lateral wall ERBT (p = 0.028) and standard ERBT (p = 0.033), with cwTm:YAG and pulsed Tm:YAG being operated in higher power modes when compared to TFL and Ho:YAG. Experts prefer long pulse modes for Ho:YAG and short pulse modes for TFL lasers.

CONCLUSION

TFL seems to have replaced Ho:YAG and Tm:YAG. Most laser settings do not differ significantly among laser sources. For experts, continuous flow irrigation is the most commonly applied measure to reduce complications.

Experts' recommendations in laser use for the endoscopic treatment of prostate hypertrophy: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group

PURPOSE

To identify expert laser settings for BPH treatment and evaluate the application of preventive measures to reduce complications.

METHODS

A survey was conducted after narrative literature research to identify relevant questions regarding laser use for BPH treatment (59 questions). Experts were asked for laser settings during specific clinical scenarios. Settings were compared for the reported laser types, and common settings and preventive measures were identified.

RESULTS

Twenty-two experts completed the survey with a mean filling time of 12.9 min. Ho:YAG, Thulium fiber laser (TFL), continuous wave (cw) Tm:YAG, pulsed Tm:YAG and Greenlight™ lasers are used by 73% (16/22), 50% (11/22), 23% (5/22), 13.6% (3/22) and 9.1% (2/22) of experts, respectively. All experts use anatomical enucleation of the prostate (EEP), preferentially in one- or two-lobe technique. Laser settings differ significantly between laser types, with median laser power for apical/main gland EEP of 75/94 W, 60/60 W, 100/100 W, 100/100 W, and 80/80 W for Ho:YAG, TFL, cwTm:YAG, pulsed Tm:YAG and Greenlight™ lasers, respectively (p = 0.02 and p = 0.005). However, power settings within the same laser source are similar. Pulse shapes for main gland EEP significantly differ between lasers with long and pulse shape modified (e.g., Moses, Virtual Basket) modes preferred for Ho:YAG and short pulse modes for TFL (p = 0.031).

CONCLUSION

Ho:YAG lasers no longer seem to be the mainstay of EEP. TFL lasers are generally used in pulsed mode though clinical applicability for quasi-continuous settings has recently been demonstrated. One and two-lobe techniques are beneficial regarding operative time and are used by most experts.

Initiating Continuous Renal Replacement Therapy in Patients With Transurethral Resection of Prostate Syndrome: A Case Report

With advances and developments in hysteroscopy, cystoscopy, transurethral resection of bladder tumor, and arthroscopy, transurethral resection of prostate (TURP) syndrome has been increasingly reported. TURP syndrome is often accompanied by severe hyponatremia, fluid overload, and a plasma hypotonic state, resulting in heart failure and pulmonary and cerebral edema. Conventional treatment methods, such as intravenous infusion of hyperosmotic saline, can rapidly reverse the downward trend of serum sodium levels in efforts to prevent and treat cerebral edema. However, this may not be suitable for patients with cardiac and renal insufficiency and may induce central pontine myelinolysis due to the possibility of worsening volume load and difficulty in controlling the correction rate of serum sodium. The patient described in this report presented with severe hyponatremia (sodium<100 mmol/L) combined with intraoperative pulmonary edema; his cardiac function and oxygenation status deteriorated after an intravenous infusion of 3% hypertonic saline. He underwent continuous renal replacement therapy (CRRT) to prevent the progression of multiple-organ edema and cardiac insufficiency. CRRT has demonstrated efficacy in the treatment of chronic hyponatremia in patients with renal failure, and can slowly and continuously correct water-electrolyte imbalance, acid-base imbalance, and volume overload. TURP syndrome with severe hyponatremia and pulmonary edema was diagnosed; accordingly, the patient was treated with 3% hypertonic saline, furosemide, and CRRT, without the development of overt neurological sequelae.

Irrigation fluid absorption during transurethral bipolar and laser prostate surgery: a systematic review

PURPOSE

Transurethral endoscopic procedures using bipolar current, or laser energy are nowadays widely accepted and have replaced the traditional monopolar resection. A major advantage of these techniques is the utilization of isotonic saline as irrigation solution, which minimizes side effects such as symptoms associated to classical transurethral resection syndrome (TUR-syndrome). Nonetheless, clinically significant IFA also occurs with saline and is determined by pressure gradients, systemic resistance and by the amount of irrigation fluid. We aimed to investigate the extend of IFA and symptoms due to volume overload during bipolar transurethral resection (bTUR) and laser procedures of the prostate.

METHODS

We performed a systematic literature search using PubMed, restricted to original English-written articles, including animal, artificial model, and human studies. Search terms were TUR, transurethral, laser, HoLEP, ThuLEP, greenlight, enucleation, fluid absorption, fluid uptake, and TUR-syndrome.

RESULTS

Mean and maximum IFA during bTURP ranges between 133 and 915 ml and 1019 ml and 2166 ml, respectively. Absorption during laser procedures can be significant with maximum values up to 4579 ml and mainly occurs during prostate vaporization techniques. Incidence of moderate to severe symptoms from iso-osmolar volume overload reaches 9%.

CONCLUSIONS

Irrigation fluid absorption during bTUR and laser surgery of the prostate is not negligible. Iso-osmolar overhydration with development of non-classical TUR-syndrome should be identified peri- and postoperatively and surgical teams should be aware of complications. Breath ethanol, venous pH, serum chloride, and bicarbonate could be markers for detecting dangerous events of IFA with saline.