[Carboxycryobiopsy and carboxycryoextraction of bladder tumor. Experimental study].

AIM: To evaluate the possibility of performing transurethral carboxycryobiopsy (CCB) and carboxycryoextraction (CCE) of a bladder tumor for pathomorphological examination, as well as to perform a comparative analysis of the safety (quality) of biopsy material (tumor tissue) during standard transurethral biopsy and carboxycryobiopsy. MATERIALS AND METHODS: In the first experiment in vitro, CCE of bladder tumor fragments obtained after transurethral resection was performed. In the second pilot study, cystoscopy followed by CCB and CCE in a patient with multiple bladder tumors was done. The procedure was performed by transurethral access. During cryopreservation of the bladder tumor, a biopsy was performed. After freezing, the tumor was removed from the bladder and sent for histological examination. RESULTS: The first experiment showed that cryoextraction of the fragments of a bladder tumor using carbon dioxide (CCE) in vitro is a feasible procedure and allows the evacuation of tumor tissues of various sizes. According to the second experiment, CCB and CCE of the bladder tumor using carbon dioxide allows to obtain a biopsy of a bladder tumor of sufficient size without compression or coagulation artifacts, which contributes to a more accurate histological evaluation. CONCLUSION: Our experiments showed that CCB and CCE of a bladder tumor using carbon dioxide are feasible procedures that contribute to obtaining better biopsy material for pathomorphological examination, and also allows to evaluate the effect of low temperatures of carbon dioxide on the biopsy material (tumor tissue).

[Puncture access with a new atraumatic needle MG for mini-percutaneous nephrolithotomy].

INTRODUCTION: An important aspect of the prevention of complications in percutaneous nephrolithotomy (PCNL) is to reduce the likelihood of injury to the adjacent structures and perirenal tissues. AIM: To determine the efficiency and safety of renal puncture during mini-PCNL with a new atraumatic needle MG. MATERIALS AND METHODS: A total of 67 patients who underwent mini-percutaneous nephrolithotomy at the Institute of Urology and Human Reproductive Health of Sechenov University were included in the prospective study. For the purpose of homogeneity of the groups, those with staghorn nephrolithiasis, nephrostomy, a history of prior kidney surgery (including PCNL), renal and collecting system anomalies, acute pyelonephritis, and blood clotting disorders were not included. The main group consisted of 34 (50.7%) patients who underwent atraumatic kidney puncture with a new needle MG (MIT, Russia), while in the control group there were 33 (49.3%) patients, who underwent standard puncture with Chiba or Troakar needles (Coloplast A/S, Denmark). The outer diameter of all needles was 18 G. RESULTS: In patients with a standard access, a hemoglobin decrease in the early postoperative period was more pronounced (p=0.024). The incidence of complications according to the Clavien-Dindo classification did not differ significantly (p=0.351), however, a JJ stent was placed in two patients from the control group due to impaired urine flow and the development of urinoma. CONCLUSION: Together with a similar stone-free rate, atraumatic needle allows to reduce a hemoglobin drop, as well as less development of severe complications.

[Early urethral catheter removal after robot-assisted radical prostatectomy].

BACKGROUND: Robot-assisted radical prostatectomy (RARP) is a widely used treatment method for patients with clinically localized prostate cancer. Posterior reconstruction of urethrovesical anastomosis (UVA) is one of the techniques that provides early recovery of urinary continence after surgery. Changes in the technique of performing posterior reconstruction of UVA may contribute to further improvement of functional results. AIM: To evaluate the functional results of early removal of the urethral catheter (after 3 days) after RARP using a modified surgical technique of performing posterior reconstruction of UVA compared with the standard catheterization time (7 days after surgery). MATERIALS AND METHODS: Patients who underwent RARP were randomly assigned to early catheter removal (3 days after surgery, main group, n=15) and standard catheterization time (7 days after surgery, control group, n=15). RARP was performed using the Da Vinci Si system. The primary end point was the rate of spontaneous voiding after catheter removal. Secondary endpoints were the incidence of urine leakage into the paravesical tissue during retrograde cystography, as well as complications according to the Clavien-Dindo system. The frequency and severity of stress urinary incontinence after catheter removal was assessed using the International Consultation on Incontinence Questionnaire - Urinary Incontinence Short Form (ICIQ-UI SF). RESULTS: There were no significant differences between groups in terms of baseline and perioperative parameters. After removal of the catheter, no acute urinary retention was observed in both groups. Also, there were no cases of urine leakage into the paravesical tissue during retrograde cystography. The ICIQ-UI SF questionnaire showed no significant differences between the groups at 1, 3, 6, and 12 months after surgery. CONCLUSIONS: The method of modified posterior reconstruction allows to remove the urethral catheter 3 days after RARP. Early removal of the urethral catheter did not adversely affect the early recovery of urinary continence, the quality of UVA, and did not increase the incidence of acute urinary retention. Further studies with longer follow-up periods are needed.

[Kidney carboxycryoablation. Pilot study].

AIM: The aim of this experimental study was to evaluate the effect of low temperatures of carbon dioxide on a "living" blood-supplying organ (pig kidney), to determine the possibility of performing cryoablation of kidney tissue with carbon dioxide (carboxycryoablation), as well as to establish experimentally modes of carboxycryoablation of the kidney. MATERIALS AND METHODS: To carry out this experimental study, a female of the mini-pig line was used. We performed laparoscopic access to the kidney for carboxycryoablation. During the freezing of the kidney, three modes were compared: 60, 90, and 120 s on one kidney of one animal. Immediately after the completion of cryoablation, nephrectomy was performed, and the removed kidney was sent for histological examination. According to the histological study, the results of the use of carbon dioxide during cryoablation of porcine kidney tissue were evaluated. RESULTS: Cryoablation based on carbon dioxide (carboxycryoablation) leads to irreversible death (necrosis) and destruction of the affected tissue. A direct relationship between the exposure mode and the size of the cryonecrosis zone was noted. Thus, the most extensive zone of necrosis with a diameter of 10 mm was achieved when performing cryoablation in the exposure mode of 120 s. CONCLUSION: This experiment showed that carbon dioxide-based cryoablation remains a feasible procedure that leads to irreversible death (necrosis) and destruction of the affected tissue. However, further studies on the safety and efficacy of cryoablation of kidney tissue with carbon dioxide are required.

[Retrograde intrarenal surgery using a 1.94 m superpulsed thulium fiber laser].

INTRODUCTION: surgical treatment of urinary stone disease plays an important role in urological practice. Stone fragmentation can be performed using various lithotripters, from which Holmium fiber laser (Ho: YAG) has currently taken the main place. According to the current literature, a superpulsed thulium fiber laser with a wavelength of 1.94 m and a maximum power output of 40 W showed in vitro higher efficiency compared to Ho: YAG, while having the same safety profile. The use of a thulium fiber laser with a pulse energy of 0.025-6 J and a high repetition rate (up to 1600 Hz) allows to most effectively perform stone dusting during retrograde intrarenal surgery (RIRS). AIM: to improve the performance of RIRS using the 1.94m superpulsed thulium fiber laser. MATERIALS AND METHODS: a total of 152 patients with renal stones who were treated during the period from February 2018 to July 2019 were included in the study. The analysis of the laser settings, their effect on retropulsion and visibility when performing RIRS using a superpulsed thulium fiber laser with a wavelength of 1.94 m and a maximum power output of 40 W, a peak power of 500 W, as well as an assessment of the stone-free rate the first postoperative day and 3 months after the procedure was done. RESULTS: The most frequently used settings were as following: 0.5 J, 30 Hz, 15 W (No. 1), 0.15 J, 200 Hz, 30 W (No. 2), 0.8 J, 31.25 Hz, 25 W (No. 3), 0.8 J, 37.5 Hz, 30 W (No. 4). The statistical analysis of the influence of the settings on the quality of endoscopic imaging and retropulsion was carried out. In addition, the features of each settings were analyzed. The stone-free rate on the first postoperative day was evaluated using low-dose CT. CONCLUSION: A superpulsed thulium fiber laser with a wavelength of 1.94 m and a maximum power of 500 W has shown high efficiency in clinical practice when performing RIRS, since it allows to have good endoscopic imaging, minimal retropulsion, and to perform stone dusting, which had a positive effect on the stone-free rate. Optimization of the settings of thulium fiber lithotripsy may improve the results of surgical treatment of urinary stone disease.

[Complications after PCNL: diagnosis and management].

Percutaneous nephrolithotomy (PCNL) is the gold standard treatment of large and staghorn kidney stones. Despite technological progress and improvement of PCNL technique, this procedure is associated with complications and in some cases remain a challenge for endourologists. According to the time, complications can be divided into intra- and postoperative. Intraoperative complications include bleeding, injury of the renal collecting system, visceral organs, pulmonary complications, thromboembolic disorders, extrarenal migration of the stone fragments and incorrect nephrostomy tube placement. Postoperative complications include infection and sepsis, bleeding, persistent urinary fistula, infundibular stenosis and death of the patient. The different recommendations that might be useful for the timely diagnosis of various complications in patients undergoing PCNL are provided in the review. Additionally, information on treatment algorithms is included.

[Design and materials for ureteral stents: past, present and future].

Ureteral stents have a long history of use. Their main goal is to provide effective drainage of the upper urinary tract. Morbidity is mostly related to low biocompatibility of materials, from which stents are made. Since stent introduction, there have been many stages of evolution and modernization. However, there is a significant problem associated with their widespread use. Despite technological progress, stent-associated symptoms, incrustation, bacterial infection are the problems that still have to be resolved while creating an "ideal" stent. The continued development of new materials and coatings also will lead to the improvement of such an indispensable urological device as the ureteral stent.

[Flexible ureteroscopy for lower pole renal stones: novel superpulse thulium (TM) fiber laser lithotripsy].

INTRODUCTION: The SuperPulse Thulium (Tm) fiber laser (wavelength of 1.94 m) has been recently introduced as a directed-energy source for urology. Preclinical studies have shown a significant potential of the SuperPulse Tm fiber laser (SP TFL) for lithotripsy. However, clinical reports of using SP TFL to treat urolithiasis are still few and limited. Of special interest are challenging cases, e.g., lower pole stones, when extreme deflection of the instrument is required. OBJECTIVE: To evaluate the effectiveness of the SuperPulse Tm fiber laser in the management of lower pole small calyceal stones during flexible ureteroscopy (F-URS). METHOD: s. The SuperPulse Tm fiber laser device (Urolase 2, IRE Polus, Fryazino, Russia) has been cleared for clinical use by the Ministry of Health of Russian Federation. Study protocol has been approved by the Ethical Review Committee. Between January 2018 and February 2019, 130 patients with kidney stones have undergone Thulium fiber laser lithotripsy during F-URS. We retrospectively analyzed 15 of this patients with a single radiopaque lower pole calculus that were included in the present study. Stone size, stone density, lithotripsy time (from the first to last footswitch press) and "lasering" (laser emission) time were measured. The SP TFL was used for stone disintegration with different settings in dusting and fragmentation modes (0.1 - 4J, 7-300Hz, 6-40W) via a fiber with a 200-m core diameter. Low dose CT scanning was performed on POD 90 to assess SFR. RESULTS: Stone size ranged from 4 to 17 mm and stone density varied from 350 to 1459 HU. The average lithotripsy time was 12 min (3-30 min). The average "lasering" time was 1.3 min (0.4-2.5 min) and the mean hospital stay was 1.1+/-0.3 days. In all cases we reached the lower pole stone containing calyx with a laser fiber. The complication rates were evaluated by using the Clavien-Dindo grading system and did not exceed GII (6.6%). SFR on POD 90 was achieved in 86.6% of cases. CONCLUSIONS: F-URS with SuperPulse Tm fiber laser is safe and effective option in the management of lower pole small calyceal stones. The possibility of using small laser fibers gives better instrument deflection which make possible to reach lower pole calyceal stones even with acute lower pole infundibulopelvic angle (IPA).

[Conservative management of rectourethral fistula: modern treatment].

INTRODUCTION: & Objectives. Rectal injury and recto-urethral fistula (RUF) formation are severe complications after surgical treatment of prostate cancer . There are various surgical techniques as well as conservative methods for the treatment of RUF. Nonsurgical approach can be used in nontoxic, minimally symptomatic patients. MATERIALS & METHODS: From 2012 to 2016, 825 patients (mean age 68y) with LPR to be performed were recruited in the study. Postoperatively RUF developed in 7 patients (0.8%) in average in 10 days after surgery. Five cases were uncomplicated presented with pneumaturia, dysuria or urine per rectum. Two patients with fecaluria and previous history of radiotherapy or androgen deprivation were excluded from the study group. Conservative management include: 1)bowel rest 2)broad-spectrum antibiotics after urine culture 3) fully absorbable diet (combination of parenteral and enteral nutrition) 4) bladder drainage (urethral catheter or suprapubic tube). Duration of conservative treatment was 4 weeks. After treatment all patients underwent a voiding cystourethrogram. RESULTS: During the treatment one patient has developed severe UTIs and surgical treatment were perfomed. The remaining 4 patients had spontaneous healing of the fistula and normal cystourethrogram. With the median follow up of 24 month after RUF treatment all 4patients had no fistula signs and they were fully continent. Overall RUF closure using nonsurgical treatment was successful in 4 of 5 cases (80%). CONCLUSIONS: Conservative management of RUF is a highly effective option which can be used to avoid major surgery and temporary colostomy. Nonsurgical treatment is a feasible method in selected patients with RUF.

[Clinical case of delayed diagnosis of tuberous sclerosis].

A clinical case of successful drug treatment of multiple renal angiomyolipomas in patient with tuberous sclerosis is presented, which suggests potential role of medical treatment of benign kidney tumors.

[The potential of endovideosurgical technologies for simultaneous ipsilateral presentation of a kidney tumor and kidney stone].

AIM: To determine the treatment strategy in patients with kidney tumors co-occurring with ipsilateral kidney stones. MATERIALS AND METHODS: During the period from 2006 to 2015, a combination of kidney tumor and urolithiasis was detected in 159 (11.5%) patients. Of these, 61 patients had indications for surgical treatment for both diseases at the time of hospitalization. The article analyzes the surgical treatment results of 14 patients with ipsilateral combination of kidney stone and kidney tumors and shows the potential of endovideosurgical technologies in managing this category of patients. RESULTS: The surgical treatment for stones was initially conducted in 3 (21.4%) patients, 4 (28.6%) patients underwent the kidney tumor surgery at the first stage, and the remaining 7 (50.0%) patients underwent one-stage surgery for both diseases. Despite the co-occurrence of two pathologies in one kidney, only 2 patients (14.3%) underwent an organ-removing operation. DISCUSSION: Combined minimally invasive organ-sparing surgery for unilateral combination of the kidney stone and kidney tumor is the most preferable treatment option, allowing the patient to get rid of both the tumor and the kidney stone within one anesthesia session. One-stage laparoscopic kidney resection with pyelolithotomy or calycolithoextraction allows preventing possible complications associated with the postoperative stone migration and eliminates the need for repeat surgery.

[Renal tumor and urolithiasis: is there a relationship?]

There is conflicting evidence on the impact of urolithiasis on the risk of developing cancer of kidney and upper urinary tract. Most researchers are of the opinion that there is a definite association between the diseases and clinicians should take the necessary measures to detect possible malignancy of the kidney and upper urinary tract in patients with urolithiasis at the earliest stages. However, the pathophysiological mechanisms that may underlie the development of renal cell carcinoma and urothelial cancer in patients with urolithiasis remain unexplored.

[Endoscopic removal of papillary tumors of upper urinary tract].

AIM: To assess the results of organ-sparing endoscopic treatment of patients with tumors of the upper urinary tract (UUT). MATERIALS AND METHODS: Twenty four patients underwent percutaneous and ureteropyeloscopic interventions for tumors of the upper urinary tract and were followed up at the Urology Clinic, I.M. Sechenov First MSMU. Retrograde removal of benign tumors of the renal pelvis and ureter (tumors sized from 5 to 35 mm), percutaneous removal of papillary carcinoma of renal pelvis of a solitary kidney, percutaneous removal of papillary carcinoma of renal pelvis of only one functioning kidney and percutaneous removal of papillary carcinoma of the lower calyx of the L-shaped kidney were performed in 21, 1, 1 and 1 patients, respectively. The patients had stage T1 papillary cancer of the upper urinary tract. There were 7 (29.2%) men and 17 (70.8%) women with mean age 64+/-5 years. Electroresection/vaporization was carried out in 18 patients, and 6 patients were treated using Holmium laser. RESULTS: None of the endoscopic procedures required conversion to open surgery or a more extended surgical operation. There were no recurrences or impaired UUT urinary flow in patients with benign UUT tumors at different points of follow-up. In 3 cases of malignant UUT tumors no recurrences occurred during 12-20 months follow-up. CONCLUSION: and discussion. Nephroureterectomy with resection of the urinary bladder is the standard radical treatment of patients with tumors of the UUT. Technological advances in endoscopic and percutaneous surgery for UUT have allowed for organ-sparing procedures in patients with neoplasms of pelvicalyceal system and ureter. The absolute indications for such organ-sparing operations now include solitary kidney or only one functioning kidney and chronic renal failure. Endoscopic resection of the tumor and renal pelvic wall within healthy tissue, including by holmium laser, with tumor stage not exceeding T1 and followed by trans-fistula chemotherapy can be regarded as an effective treatment for patients with tumors of pelvicalyceal system.