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Biomedical subjects

A G Martov

Publications and source records attributed to A G Martov.

At least 19 recordsLinked to original sources
PubMed2001

Contractile function of upper urinary tract after indwelling ureteral prosthesis: experimental investigation.

BACKGROUND: Ureteral endoprostheses are used for dilatation of strictures in order to maintain upper urinary tract (UUT) function for a longer period. MATERIALS AND METHODS: Three kinds of short (3-4-cm) endoprostheses were inserted into the ureter of mongrel dogs with intact UUT or experimental ureter strictures. The UUT function was evaluated by means of radiographic examinations and in terms of following measures of contractility: intraluminal pressure, electroureterography (EUG), and multichannel impedance ureterography (MIUG). Studies were performed 1, 3 to 6 months, and 1 to 3 years after prostheses implantation. RESULTS: Similar urodynamic changes were registered in prosthetically treated ureters of dogs with initially intact UUTs and those with ureteral strictures. These disorders consisted of increased UUT intraluminal pressure and different functioning of the upper and lower regions of the ureter. The bioelectric and contractile activity of the upper UUT regions was reinforced, accelerated, and dysrhythmic, while peristaltic ureter wall function below the endoprosthesis was rare and weak. CONCLUSIONS: The changes observed are typical for ureteral prosthetics. The UUT urodynamic alterations could be attributable entirely to the excluding of the ureteral segment from active contraction and were the result of the local absence of the ureteral wall closing mechanism. One must keep in mind that UUT endoprostheses produce a high load on the ureter wall. The transition from UUT hyperfunction to contractile function decompensation may depend on the intrinsic compensatory reserves of the ureter.

Animals↗
PubMed2000

An endourologic approach to complete ureteropelvic junction and ureteral strictures.

BACKGROUND AND PURPOSE: Complete stricture of the ureteropelvic junction (UPJ), ureter, or both represents a secondary upper tract obstruction and is a challenge for surgical management. The endourologic repair of these complete strictures remains controversial because of the many unsatisfactory results in the literature. The aim of this study was to achieve recanalization of the ureter or the UPJ using endourologic techniques to prove durable success of this technique. PATIENTS AND METHODS: We present data on the 21 patients with complete UPJ or ureteral strictures treated over 5-year period. The length of the obliterated portion of the ureter or UPJ ranged from 0.3 to 1.7 cm. The stricture was at the UPJ level in 12 patients (57%), in the upper ureter in 3, and in the lower ureter in 4. The technique was a combined approach, with antegrade introduction of the guidewire and retrograde cold-knife incision in the majority of the cases. In five cases, the incision was carried out in the reverse direction with a guidewire introduced retrograde up to the stricture level. An originally designed 6F to 7F polyethylene double-J stent with a movable 12F to 16F silicon sheath or percutaneous tube was placed at the completion of the procedure. RESULTS: The follow-up period ranged from 6 to 48 months. Recanalization was achieved in 17 patients (81%), of whom 14 became symptom free. Other surgical outcomes necessitated open surgical intervention (pyeloplasty, nephrectomy) in two patients. One patient developed a clinically significant recurrent urinary tract infection and deterioration of kidney function. Thus, the overall success rate of the endourologic management of the complete UPJ and ureteral strictures was 67% in our series. CONCLUSION: Endourologic management with retrograde or antegrade pyeloureterotomy can be successful in patients with short (up to 1.0-cm) obliterative strictures who are without extensive hydronephrosis and with preserved renal function.

Adolescent↗
PubMed1993

[The effect of upper urinary tract interior drainage on urodynamics and contractile function of the ureteral wall].

S-stents were introduced to the upper urinary tracts of experimental dogs on a period from 1 week to 11 months. It was found mild ureter dilation, the increased ureter pressure, refluxes along the upper urinary tract, the lowered flow resistance during perfusion and diuretic loads. Isolated ureter wall fragments demonstrated the diminished contractility in vitro, and the mode of their contractile force adrenergic regulation was modified. The reduced ureter pressure during large flows after indwelling S-stents to the ureters may be the factor that facilitated the renal and ureter stones removing but the decreased contractility and ureter refluxes emphasized that the period of stent implantation to the upper urinary tracts must be pathogenetically and clinically evident.

Animals↗
PubMed1989

[Shockwave destruction of stones in the kidneys and ureters].

Experience gained in the use of the first Soviet unit and western lithotriptors is based on the treatment of over 2500 patients of different age groups. Comparative characteristics of lithotriptors are provided to mark substantial advantages of the Soviet unit. Distant lithotripsy (DL) is much more effective and atraumatic as compared with conventional surgical interventions. The use of DL provides positive effect in 97-99% of cases. The rate of complications is extremely low, amounting to 5-10%. Indications and contraindications as to the use of DL are given. Contraindications include cases requiring reconstructive surgical interventions and the presence of coral-like calculi and acute inflammation. The Soviet unit appeared especially effective in the treatment of children with urolithiasis. The cure was attained in 97.2% of the patients, no serious complications occurred. Functional studies of the kidneys did not reveal any changes both in the short- and long-term periods after DL.

Adolescent↗
PubMedDate not supplied

[Surgical treatment of urinary bladder cancer].

Ultrasonic transabdominal and transrectal investigations, computed tomography, endoscopic photodynamic studies, polyfocal biopsy of the urinary bladder were used in examination of 1238 patients which were diagnosed to have urinary bladder cancer. 894 patients underwent transurethral resection of the bladder. Morphologically, cancer of the urinary bladder has an inductory effect on intact parts of the bladder mucosa. This means that even most radical resection does not eliminate grounds for a new tumor growth. Radical cystectomy was performed in diffuse papillomatosis, multiple stage T2 tumors of high-grade malignancy, tumors at stage T3, T4, Nx, MO, in rapid recurrent tumors after conservative or operative treatment.

Cystectomy↗
PubMedDate not supplied

[Vaporizing resection - a new treatment of benign prostatic hyperplasia].

Though transurethral resection (TUR) remains a routine treatment for benign prostatic hyperplasia (BPH), its complications observed in up to 18% of patients necessitate active search for novel endoscopic methods. Vaporizing resection (VR) is among them. It makes use of two electrosurgical techniques of tissue removal--resection and vaporization--which provide adequate removal of the tissue and good coagulation. VR was made in 84 BPH patients aged 57-82 years. 19 of them had epicystostomy. 1-year follow up examination showed that complaints index by IPSS scale diminished from 21.9 to 4.6, life quality--from 3.9 to 1.1, urine residual volume--from 118 to 19 ml, maximal urination rate Qmax increased from 6.7 to 18.5 ml/s. Thus, the scheme of BPH patients' examination, the operative technique and indications in VR are the same as in TUR, while the course of the postoperative period, frequency and type of complications are typical for electrovaporization: minimum of hemorrhagic complications, low probability of TUR-syndrome, less severe postoperative period, etc.

Aged↗
PubMedDate not supplied

[Application of resectoscope of Marberger type with cutting and vaporizing loops in the treatment of benign prostatic hyperplasia].

One of the latest achievement in the design of tools for TUR is introduction of a new resectoscope constructed by M. Marberger. Its oval loops can remove 30% more tissue than it is made by a standard resectoscope with semicurcular loops. 203 patients with benign prostatic hyperplasia (BPH) were operated using Marberger resectoscope, 54 BPH patients were operated using a standard resectoscope. 12-month follow up results of both TURs did not differ much. The advantage of the new tool is quicker removal of the tissue.

Electrocoagulation↗
PubMedDate not supplied

[Transurethral rotoresection - a new method of benign prostatic hyperplasia treatment].

Karl Storz company (Germany) offers a novel endoscopic technology in the treatment of benign prostatic hyperplasia (BPH) i.e. rotoresection which combined mechanic and electrosurgical methods of removal of the hyperplastic tissue. The operation is performed with application of a special rotoresectoscope connected with a rotor electrode which, in its turn, is connected with mechanical rotor generator making it to rotate and with powerful electrogenerator (radiotome). The hyperplastic tissue is removed both mechanically (by high-frequency rotation of the rotor tip) and due to electrovaporization with simultaneous coagulation of the underlying tissue layers. Transurethral rotoresection was performed in 40 patients with BPH. Intraoperative and postoperative complications were not observed. Examination at discharge and 1 month after surgery showed a 4-fold decrease in the prostatic symptoms by IPSS scale, residual urine decreased 3-fold, maximal urine flow rate rose 2.5-fold. Transurethral rotoresection combines effective removal of BPH tissue with minimal intraoperative bleeding. It is a good alternative to conventional TUR. For more detailed evaluation further studied are needed.

Cystoscopes↗
PubMedDate not supplied

[Percutaneous paracentric nephrostomy in infants].

The paper describes the technique of transcutaneous paracentetic nephrostomy in infants, emphasizes advantages of this method in infants versus the others used to correct supravesical obstruction (open nephrostomy, ureterocutaneostomy, kidney catheterization, internal stenting), describes relevant indications. The nephrostomy was performed in 16 infants. The results show effectiveness and safety of this method.

Child, Preschool↗
PubMedDate not supplied

[Internal prosthetic appliance of ureter (experimental study)].

In experiment, endoprosthetic appliances were placed in the intact ureters of 5 dogs, in previously created stricture also in 5 dogs. Three types of endoprostheses were used: nitinol thermo-extensible spiral prosthesis (Russia), reticular extensible vascular endoprosthesis Wallstent (Schneider, Switzerland) and tough teflon biliary prosthesis (Olympus, Japan). The dogs were followed up 1-36 months. Regardless of the prosthesis type, in good patency, in all the cases excretory urography and dynamic nephroscintigraphy demonstrated moderate dilatation of the upper urinary tracts, slowing down of urine evacuation. Urodynamic investigations detected arise in intraureteral basal and peristaltic pressure, transient more frequent contractions above the prosthesis and persistent less frequent contractions of the distal ureter, increased amplitude of the contractions. The contractions became arrhythmic, retrograde waves arose. Later, some dogs had chaotic contractions. It is concluded that endoprostheses reestablish patency of the urinary tracts but hinder contractions in part of the ureter thus affecting negatively urodynamics.

Animals↗
PubMedDate not supplied

[Percutaneous intrarenal ultrasonography].

In vivo and in vitro experiments were made to study percutaneous intrarenal ultrasonography (PIU). The transurethral ultrasonic probe (5.5 MHz, 1850 "Bruel&Kjer, Denmark) was inserted through the nephrostomic fistula in the dilated pelvis with the tubus of the nephroscope K. Storz 27093B. Scanning of the cavitary renal system and ureteropelvic zone was conducted by moving the probe in the longitudinal and transverse directions. The experiment on 21 removed kidneys investigated potentialities of PIU in hydronephrotic transformation caused by ureteropelvic stricture (4 kidneys), urolithiasis (7 kidneys), carcinoma of renal parenchyma (5 kidneys), pelvic cancer (1 kidney), combined renal cell and epithelial renal carcinoma (1 kidney); in pyonephrosis (1 kidney) and contracted kidney (2 kidneys). 43 patients (19 males and 24 females aged 7 to 63 years) have undergone PIU in the course of percutaneous nephrolithotripsy (n = 23), percutaneous endopyelotomy (n = 15) and percutaneous endoresection of solitary renal cyst (n = 5). PIU accurately localizes residual and x-ray-negative concrement fragments raising the effectiveness of percutaneous nephrolithotripsy, precisely differentiates internal renal structures, visualizes pelvic wall, vessels and tissues of the renal sinus, provides additional information about ureteropelvic zone and its changes. PIU can find wide application in intraoperative diagnosis of different renal and upper urinary tract diseases.

Adolescent↗
PubMedDate not supplied

[Radiographic-endoscopic diagnosis and treatment of obliterations of the upper urinary tract].

Potentialities of x-ray endoscopic diagnosis and treatment of upper urinary tracts (UUT) obliterations were studied in 26 and 21 patients, respectively. The causes of obliteration were previous urological, surgical, gynecological operations, radiotherapy (one case). Percutaneous or transurethral UUT recanalization was performed in 5 and 16 patients, respectively. The length of the obliteration varied from 0.3 to 1.7 cm. It was located at the level of ureteropelvic segment in 13(62%), in the upper third of the ureter in 4(19%) and in the lower third of the ureter in 4(19%) patients. UUT endoscopic recanalization was successfully performed in 17(81%) patients. The operation took 60-90 minutes. Minor complications were corrected conservatively. Control examination was made after 6 to 15 years follow-up. The result was assessed as positive in the absence of clinical symptoms, recurrent stricture(obliteration), in improvement or no change in renal function. These criteria were met in 14(66.7%) patients. One patient has undergone nephrectomy because of highly deficient renal function and dislocation of the nitinol spiral outside recanalization zone. Two patients live with drained kidney in spite of UUT restored patency. The method proved effective and can be used as first-line therapy in short obliteration (< 1 cm), relatively intact renal function and in the absence of UUT marked hypotonia, more so as the failure does not complicate further surgery. Combined x-ray endoscopic diagnosis is presently most significant in determination of complete stricture(obliteration) of ureteropelvic segment and the ureter, its length and location.

Adolescent↗
PubMedDate not supplied

[Choice of YAG-Nd mode for conduction of interstitial laser coagulation in benign prostatic hyperplasia].

Basing on the results of fundamental and experimental investigations, we have selected the YAG-Nd laser mode for interstitial laser coagulation (ILC) of the prostate using laser unit LAMIN-1 made in Russia. The experiments were performed on cadaver prostates (3 macropreparations of human prostate 50-80 cm3 in volume). The samples were exposed to laser radiation after their immersion into 5% glucose solution. Laser worked with impulse frequency 30 Hz, power 30-50 W, time of exposure 20-50 s. In exposure 30-40 or 20 s recommended power is 30 or 40-50 W, respectively. The resultant coagulation necrosis covers 2.8-2.9 cm3, carbonized layer is absent. The above mode was used in 10 operations in 65-85-year-olds. The duration of the intervention was 10-15 min maximum. The sites were 3-5 in the lateral lobe and 2 in the middle lobe of the prostatic gland. The outcomes were followed up for 12 months. The comparison of the mean control values with those before the procedure provided the following picture after 12 months: preoperative IPSS 21.9 vs 9.3 scores postoperatively; residual urine 140 vs 30 cm3; maximum urination rate 6.7 ml/s vs 13.5 ml/s, respectively. For interstitial laser coagulation we think it valid to use high laser power and short exposure because short duration of the operation, complete hemostasis, minor lesion of the urothelium, unnecessary long-term drainage of the urinary bladder minimize the risk of intra- and postoperative complications.

Age Factors↗
PubMedDate not supplied

[Endoscopic treatment of bladder diverticula].

Transurethral endoscopic incision of the urinary bladder's diverticular neck has been performed in 29 patients aged 44 to 90 years (mean age 65 years). 25(86.2%) patients had verified concomitant diseases and high anesthesia risk prohibiting radical surgery. According to preoperative diagnosis, the volume of the diverticula ranged from 20 to 700 ml, the diameter of the neck--from 0.3 to 2.0 cm. 10 patients had multiple diverticula. Uroflowmetry registered the maximal urinary flow rate (Qmax) within 2.1-5.3 ml/s. In all the patients surgery was performed under epidural anesthesia, simaltaneously with transurethral resection (TUR) of benign prostatic hyperplasia in 18 patients, with TUR of the urinary bladder neck or incision of the prostate because of its sclerosis in 11 patients. In 2 cases there was also TUR of the bladder for papillary cancer involving the bladder wall and the diverticulum, in 6 cases one-stage pneumatic or mechanical cystolithotripsy was performed. No intraoperative complications occurred. After the operation all the patients resumed normal micturition. Control examination after 6-48-month follow-up Qmax rose to 14.1-23.0 ml/s. Neither ultrasound investigation nor cystography detected diverticulum in 13 patients. The size of the diverticulum diminished in size in 16 patients. Residual urine in large diverticula (14 patients) was 50 ml maximum. 12 months after the operation 1 patient developed recurrent sclerosis of the prostate with reappearance of residual urine. He was reoperated (TUR of the prostate) without incision of the neck of the diverticulum. Postoperative complications were the following: mild electric burn of the thigh (1 case), acute epididimitis treated conservatively (1 case) and early postoperative bleeding which required endoscopic revision of the bladder and coagulation of the bleeding vessel from the cut neck of the diverticulum (1 case). Thus, transurethral incision of the bladder's diverticular neck is effective and low-traumatic intervention which in patients with severe somatic pathology is an alternative to the open surgery, while in patients without such pathology it does not complicate open operation (diverticulectomy) if it becomes necessary.

Adult↗