Biomedical subjects

Alexander Belenky

Publications and source records attributed to Alexander Belenky.

At least 19 recordsLinked to original sources

PubMed2006

MR angiography for abdominal and thoracic aortic aneurysms: assessment before endovascular repair in patients with impaired renal function.

OBJECTIVE: The aim of the study was to establish the feasibility of using MR angiography as the sole imaging technique before endovascular repair of abdominal or thoracic aortic aneurysms and to compare preprocedural measurements by MR angiography and digital subtraction angiography in patients with impaired renal function. CONCLUSION: MR angiography appears to be effective and reliable for use as the sole imaging method before endovascular repair of aortic aneurysms in patients with renal impairment.

Aged↗

PubMed2005

Embolization of transected vertebral arteries in unstable trauma patients.

The aim of this paper is to report our experience with coil embolization for the treatment of vertebral artery transection in unstable trauma patients. The course of four patients admitted to our units between 1998 and 2003 with traumatic injuries of the upper thorax or neck is described. All had unstable hemodynamic parameters at presentation. Emergent arteriogram revealed vertebral artery transection, which was managed by immediate coil embolization proximal to the injury site. Initial technical success was achieved in all four patients, with hemodynamic improvement. No further treatment or surgery to control the vessel injury was needed. There were no immediate or late complications of the procedure and no neurological sequelae. Emergency coil embolization is an effective endovascular technique for use in unstable patients with angiography findings of a transected vertebral artery.

Adolescent↗

PubMed2005

Intraoperative ultrasonography: a tool for localizing small colonic polyps.

BACKGROUND AND AIMS: Small colonic polyps are difficult to palpate and thus difficult to localize during surgery. Preoperative injection of dyes and "on-the-table colonoscopy" are some of the methods used to allow the surgeon to find the polyps. The aim of the present study was to evaluate the value of intraoperative ultrasound as a tool that may allow detection of small colonic polyps during surgery. RESULTS: The study population consisted of nine consecutive patients referred to surgery for polyps of the large bowel that were not amenable to endoscopic removal. At surgery, the colon was filled with saline and than scanned by linear ultrasound probe. In 8 out of 9 patients, intraoperative ultrasound successfully detected all polyps, even those smaller than 0.5 cm. In one patient with two polyps, one in the right colon was easily localized, but a second flat, 0.4-cm tubular adenoma at the splenic flexure was missed. In three patients, intraoperative ultrasound showed penetration into the muscular coat. These polyps were found on pathology to be invasive cancer. CONCLUSION: Intraoperative ultrasound makes it possible for surgeons to easily localize small nonpalpable polyps of the large bowel. Furthermore, it can determine the aggressive potential of these lesions with great accuracy.

Adult↗

PubMed2005

Percutaneous transluminal angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child after liver transplantation.

Percutaneous transluminal angioplasty is increasingly used in children. We present a case of successful balloon angioplasty of an occluded surgical splenorenal shunt in a 4-year-old child who underwent liver transplantation because of biliary atresia. Percutaneous reopening of the shunt is a relatively safe procedure that may spare patients of surgical intervention.

Angioplasty, Balloon↗

PubMed2005

Sonographic diagnosis of right segmental omental infarction.

PURPOSE: The purpose of this study was to identify the characteristic features of omental infarction so that this entity can be differentiated from other acute conditions in the right lower quadrant of the abdomen. METHODS: A retrospective review was undertaken. We searched our hospital medical records and found 6 patients with the diagnosis of omental infarction in the last 3 years. Clinical, sonographic, and CT findings at the time of hospital admission and at follow-up were studied. RESULTS: In 5 of the 6 patients (83%) sonography demonstrated a moderately hyperechoic, noncompressible ovoid mass located in the omental fat between the umbilicus and the right colon corresponding to the point of maximal tenderness or to the site of a palpable lesion on physical examination. In 1 patient, sonography revealed no abnormalities. In all patients, the diagnosis of omental infarction was confirmed by CT. One patient underwent laparoscopy because of intractable pain; laparoscopy revealed a necrotic segment in the omentum, and pathologic analysis confirmed the original diagnosis. CONCLUSIONS: Omental infarction is a benign self-limited disease that can mimic acute abdomen. The diagnosis can be established preoperatively with sonography and CT, which may avoid unnecessary laparotomy.

Abdomen, Acute↗

PubMed2005

Evaluation of the analytical performance characteristics of the Bayer ACS:180 B-type natriuretic peptide (BNP) assay.

BACKGROUND: B-type natriuretic peptide (BNP) is a cardiac hormone that regulates hemodynamic equilibrium and alleviates ventricular stress. In patients with chronic heart failure, BNP levels increase in proportion to the severity of clinical symptoms and degree of decreased left ventricular ejection fraction. BNP has clinical utility in the evaluation, management, and prognosis of patients with heart failure. METHODS: We evaluated the analytical performance characteristics of the BNP immunochemiluminometric assay in the ACS:180 instrument at three hospital laboratory sites. The analytical performance characteristics evaluated included imprecision, sensitivity (minimum detectable concentration, MDC), analytical measurement range (AMR), dilution linearity/recovery, lot-to-lot reagent variation, high-dose hook effect, and comparison against ADVIA Centaur BNP results on patients' EDTA-plasma samples. RESULTS: Total imprecision was <10% coefficient of variation at BNP concentrations of 43-1830 pg/ml; MDC was 6.9 pg/ml; AMR was 6.9-5000 pg/ml; overall recovery of BNP in samples diluted up to 1:10 was 98%; there was no lot-to-lot reagent variation in BNP results and no high-dose hook effect at BNP concentrations up to 100,000 pg/ml; and, ACS:180 results were highly correlated (r=0.996) with Centaur BNP results. CONCLUSIONS: The ACS:180 BNP assay demonstrated excellent analytical performance characteristics and agreement with BNP results obtained using the Centaur instrument.

Cardiac Output, Low↗

PubMed2005

Balloon angioplasty of popliteal and crural arteries in elderly with critical chronic limb ischemia.

OBJECTIVE: Elderly patients with extensive infrainguinal peripheral vascular disease and critical chronic limb ischemia (CCLI) are poor surgical candidates. Our purpose was to evaluate angiographic and clinical results of popliteal, infrapopliteal, and multi-level disease percutaneous transluminal angioplasty (PTA) in such patients. DESIGN: Retrospective study of angiographic and clinical files in selected group. MATERIALS AND METHODS: Between 1996 and 2002, 38 elderly patients aged 80-94 years old (mean age 83.3) with critical leg ischemia were treated with PTA. All patients were at high surgical risk. 31/38 (81.5%) patients had chronic non-healing wounds, and 14/38 (37%) had multi-level disease of superficial femoral, popliteal and crural arteries. One hundred and two lesions were treated by angioplasty. Immediate angiographic and 1 year clinical results were retrospectively analyzed. RESULTS: The overall procedural success rate was 32/38 (84.2%). There were three major complications (7.9%), but no deaths, and three technical failures, all were of infrapopliteal lesions. After 1 year, 27 patients could be followed, five patients died during the first year of unrelated causes. Twenty-three patients (85.2%), were clinically re-occluded within 1 year, but complete and partial wound healing was achieved in 80% (16/20) and rest pain improvement in 57% (4/7), so that overall limb salvage was 74% (20/27). CONCLUSIONS: Elderly patients with multi-level CCLI have a short patency term following angioplasty of 14.8% after 1 year. Nevertheless, this temporary vascular patency enables wound healing or improvement in 74% of these patients, thus such endovascular interventions are recommended in this age group.

Aged↗

PubMed2005

Uterine artery embolization: a pilot study in a rabbit model.

Eight female adult ex-breeder New Zealand white rabbits underwent bilateral, unilateral, or superselective unilateral uterine artery embolization. The histopathologic changes after embolization in New Zealand white rabbits resemble those in humans, making rabbits an appropriate model for experimental uterine artery embolization.

Animals↗

PubMed2005

Use of peripheral cutting balloon in the management of resistant benign ureteral and biliary strictures.

PURPOSE: To report the initial and midterm results of percutaneous cutting balloon incision and dilation (PCBID) for the treatment of benign ureteral and biliary strictures in patients after failed high-pressure balloon dilation. MATERIALS AND METHODS: The study sample consisted of 11 patients: three with ureteric strictures after renal transplantation, three with biliary anastomotic strictures after liver transplantation, three with pelvic metastatic disease compressing the ureter, one after a failed endoscopic papilla of Vater sphincterotomy, and one with tight stenosis at the choledochojejunal anastomosis. All strictures were resistant to high-pressure balloon dilation. Four patients underwent PCBID immediately after failed high-pressure balloon dilation in the same session, and seven underwent the procedure in a separate session within the subsequent week. The width of the peripheral cutting balloons did not exceed the diameter of the normal lumen (7-8 mm). RESULTS: PCBID was successful in nine patients (82%). One failure occurred in a transplanted ureter and one occurred in a transplanted liver with a choledochocholedochal anastomosis. In both cases, PBCID was performed in the same session as failed high-pressure balloon dilation. There were no periprocedural complications. Patency was confirmed at the 3- and 6-month clinical and ultrasonographic follow-up. CONCLUSION: PCBID is a simple minimally invasive method for the treatment of benign ureteric and biliary strictures. The success rate is high and no complications occurred.

Adult↗

PubMed2005

Epidermoid cyst and teratoma of the testis: sonographic and histologic similarities.

OBJECTIVE: The classic sonographic description of an epidermoid cyst is a mass with a target or onion ring appearance of alternating rings of hyperechogenicity and hypoechogenicity. This study presents a pathologic-sonographic assessment of classic and nonclassic appearances of an epidermoid cyst of the testis and reports the possible similarity between a classic epidermoid cyst and a teratoma on sonography. METHODS: We reviewed the sonographic and histologic features of 8 testicular tumors that either had a classic onion ring pattern or were found at pathologic examination to be epidermoid cysts but did not have the classic sonographic pattern. RESULTS: Three epidermoid cysts had a typical onion ring appearance. Histologic sections of these tumors revealed a squamous epithelial layer lining the cyst and multiple concentric laminated layers of keratin. Two tumors did not have a typical sonographic appearance of epidermoid cysts but were found to be epidermoid cysts at pathologic examination. One was homogeneously hypoechoic, and the other had irregular cystic and solid components, but neither had a target or onion ring appearance. Histologically, both of these tumors consisted of cystic cavities lined by squamous epithelium and contained desquamated keratinized epithelium. Notably, 3 other tumors pathologically diagnosed as teratomas had a sonographic appearance of classic epidermoid cysts. These tumors contained layers of keratin, but the cyst was lined by both squamous cells (ectodermal origin) and cylindrical epithelium (endodermal origin), thereby precluding the diagnosis of epidermoid cysts. CONCLUSIONS: There is considerable overlapping of the sonographic appearances of teratomas and epidermoid cysts of the testis. Although the onion ring appearance of an intratesticular tumor is suggestive of an epidermoid cyst, this appearance may also be found in cases of a teratoma. Whereas the former condition can be treated by local enucleation, the latter requires radical orchiectomy.

Adult↗

PubMed2004

Elevation of serum testosterone and free testosterone after embolization of the internal spermatic vein for the treatment of varicocele in infertile men.

BACKGROUND: To evaluate the effect of internal spermatic vein (ISV) embolization on levels of serum testosterone and free testosterone and on spermatogenesis. METHODS: The files of 83 infertile men treated for varicocele were reviewed for changes in serum testosterone, free testosterone and spermatogenesis after ISV embolization. RESULTS: Mean serum testosterone concentration rose after embolization by 43%, from 12.07 +/- 6.07 nmol/l to 17.22 +/- 8.43 nmol/l (P<0.001). Mean serum free testosterone concentration rose by 72%, from 5.93 +/- 2.44 nmol/l to 10.21 +/- 7.69 nmol/l (P<0.001). Mean sperm concentration increased from 7.49 +/- 1.73 x 10(6)/ml to 18.14 +/- 2.36 x 10(6)/ml (P<0.001); mean sperm motility increased from 21.74 +/- 2.47 to 34.47 +/- 2.27% (P<0.001); and mean sperm morphology increased from 6.63 +/- 1.07 to 13.08 +/- 1.44% (P<0.001). CONCLUSIONS: ISV embolization apparently induces an increase in both serum testosterone and free testosterone concentrations and in sperm parameters in infertile patient with varicocele, regardless of the size of the varicocele.

Adult↗

PubMed2004

Transhepatic balloon dilatation of early biliary strictures in pediatric liver transplantation: successful initial and mid-term outcome.

PURPOSE: To evaluate the initial and mid-term outcomes of transhepatic balloon dilatation for the treatment of early biliary strictures in lateral left-segment liver transplants in young children. METHODS: Between April 1997 and May 2001, seven children aged 9 months to 6 years with nine benign strictures in left-segment liver grafts were treated percutaneously. Sessions of two or three dilations were performed three or four times at average intervals of 10-20 days. In each session, the biliary stenoses were gradually dilated using balloons of 3-7 mm. Follow-up ranged from 12 to 54 months (mean 27 months, median 12 months). Clinical success was defined as resolution of the stenosis, normalization of liver enzymes and lack of clinical symptoms RESULTS: Technical success was achieved in all nine strictures. Hemobilia occurred in one patient and was successfully treated. On follow-up, all patients had complete clinical recovery with normalization of liver function and imaging of patent bile ducts. CONCLUSION: Balloon dilatation is an effective and relatively safe method for the treatment of early biliary strictures in left-segment liver transplantation in young children. We recommend this approach as the initial treatment for early strictures. Metal stents or surgery should be reserved for patients with late appearance of strictures or failure of balloon dilatation.

Anastomosis, Surgical↗

PubMed2004

The effect of class-specific protease inhibitors on the stabilization of B-type natriuretic peptide in human plasma.

BACKGROUND: B-type natriuretic peptide (BNP) is a cardiac hormone that regulates hemodynamic equilibrium. In the circulation, its activity is controlled by proteolytic factors. Accurate measurement of BNP in a patient's plasma may be affected by degradation due to proteolysis. OBJECTIVE: We report on the identification and performance of classes of protease inhibitors that stabilize BNP in plasma. DESIGN AND METHODS: Using the Bayer ADVIA Centaur BNP assay, we measured the effect of arginine, serine and/or specific kallikrein protease inhibitors (PIs) on exogenous spiked or endogenous BNP in patient plasma. RESULTS: Compared to controls without inhibitor, all PIs were capable, to varying degrees, of retarding the rate of proteolytic degradation. The kallikrein-specific inhibitor, D-Phe-Phe-Arg-chloromethylketone (PPACK II) was most effective as a single constituent and was able to eliminate BNP degradation in patient samples for up to 6-10 days when stored at 2-8 degrees C. CONCLUSIONS: The stability of BNP was markedly increased in the presence of kallikrein-specific PPACK II and a broad spectrum of serine PIs. Use of these compounds offers a simple method of extending sample handling and storage of plasma samples containing BNP.

Amino Acid Sequence↗

PubMed2004

Varicocele: a bilateral disease.

OBJECTIVE: To evaluate the prevalence of varicocele in the left and right spermatic veins in infertile men by several methods of examination. DESIGN: Prospective study. SETTING: Andrology unit of a department of obstetrics and gynecology, and interventional radiology unit of the radiology department at a tertiary care facility. PATIENT(S): Two hundred eighty-six infertile men evaluated for varicocele. INTERVENTION(S): Patients underwent evaluation for infertility. Physical examination was followed by contact thermography, Doppler sonography, and venography of both testes. MAIN OUTCOME MEASURE(S): We measured the prevalence of varicocele in the left and right spermatic veins in infertile men, and the response of semen parameters after embolization of internal spermatic vein. RESULT(S): Varicocele was detected by one of the noninvasive methods and confirmed by venography in 255 patients (89.2%): the left site in 45 (17.6%), the right side in 4 (1.5%), and bilaterally in 206 (80.8%). All patients were treated by embolization. Mean sperm concentration increased from 6.12 +/- 1.02 to 21.3 +/- 1.69 million/mL; mean sperm motility from 16.81 +/- 1.51 to 35.90 +/- 1.41%; and mean sperm morphology from 9.75 +/- 0.85 to 16.92 +/- 1.17%. Pregnancy rate was 43.5%. CONCLUSION(S): The present study finds that what was traditionally considered a predominantly unilateral anatomical abnormality apparently has a strikingly high bilateral prevalence (80.7%). This may suggest that we should consider varicocele a bilateral disease. The second finding is the high rate of varicocele detected by venography, thermography, and sonography when compared with physical examination results. Our study may have important implications for treatment, indicating that patients with clinical evidence of unilateral left varicocele should be carefully evaluated for bilateral varicocele.

Functional Laterality↗

PubMed2004

Incidental testicular tumors in infertile men.

OBJECTIVE: To characterize the population of infertile men with an incidental finding of testicular tumor diagnosed during infertility work-up and to describe their unique presentation and pathological findings. DESIGN: Retrospective study of 11 men in whom a testicular tumor was incidentally diagnosed during evaluation for infertility out of 150 patients who underwent orchiectomy over a 10-year period (1992 to 2002). SETTING: University-affiliated urologic referral center. PATIENT(S): Infertile men with an incidental testicular mass who underwent radical orchiectomy. INTERVENTION(S): Description of patient characteristics: age at diagnosis, presentation, history of undescended testis, and type of infertility. MAIN OUTCOME MEASURE(S): Tumor size and location and pathological diagnosis. RESULT(S): Eleven patients met the study's inclusion criteria, 11 tumors were identified and characterized. The tumors were usually small, centrally located and nonpalpable. Histologically, six were malignant germ-cell tumors and three were Leydig-cell tumors; two patients had no histologic evidence of tumor. All patients with a history of undescended testis had malignant germ-cell tumors. CONCLUSION(S): The use of trans-scrotal sonography enables early diagnosis of small nonpalpable tumors. A history of an undescended testis may necessitate a more aggressive approach, as these patients are at increased risk for testis cancer. Further studies are warranted to establish the yield of routine sonographic screening of infertile men and their specific management.

Adult↗

PubMed2004

External-internal nephro-uretero-ileal stents in patients with an ileal conduit: long-term results.

OBJECTIVES: To describe an improved technique for upper urinary tract drainage in patients with ureteroileal anastomotic stricture after radical cystectomy and urinary diversion to an ileal conduit, and to review our experience and long-term results. METHODS: From 1995 to 2002, 16 patients (18 renal units) with ureteroileal anastomotic stricture after radical cystectomy and urinary diversion to an ileal conduit underwent external-internal nephro-uretero-ileal stent placement. The procedure consisted of three stages: insertion of a percutaneous nephrostomy tube; retrograde external-internal stent placement with the help of an antegrade-inserted wire, leaving the stent's port in the stoma bag; and periodic retrograde stent exchange. The median duration of follow-up was 26.6 months. RESULTS: The overall success rate was 94.7%. No serious complications occurred during the procedure or during follow-up. Patient compliance was fairly good. In 75% of the patients, the stent served as the definitive treatment, avoiding the need for surgical revision. CONCLUSIONS: External-internal nephro-uretero-ileal stent placement can be used successfully and safely as a definitive treatment for anastomosis-related complications in patients after radical cystectomy and urinary diversion to an ileal conduit.

Aged↗

PubMed2004

Physical examination may miss the diagnosis of bilateral varicocele: a comparative study of 4 diagnostic modalities.

PURPOSE: We evaluated the sensitivity of 3 noninvasive methods for detecting left and right varicoceles. MATERIALS AND METHODS: Three noninvasive methods for the detection of varicocele in the left and right internal spermatic veins were evaluated in 214 infertile men, namely, physical examination, scrotal contact thermography and ultrasound Doppler. Venography was used as the reference diagnosis. RESULTS: Varicocele was detected in 195 patients (91.1%), on the left side in 37 (19%), on the right side in 3 (1.5%) and bilaterally in 155 (79.5%). Scrotal contact thermography using varicoscreen proved to be the most accurate method. Sensitivity, specificity, accuracy and positive predictive value were 98.9%, 66.6%, 98.5% and 100%, respectively, for left varicocele, and 95.6%, 91.6%, 94.9% and 98%, respectively, for right varicocele. Doppler sonography was associated with the highest number of false-positive results. Accuracy in evaluating retrograde flow was lowest for both sides for physical examination and highest for the combination of Doppler sonography and contact thermography, with a sensitivity, specificity, accuracy and positive predictive value of 100%, 33.3%, 99.0% and 98.9%, respectively, for the left side, and 97.4%, 58.3%, 90.3% and 91.1%, respectively, for the right side. In 165 (85%) of the 195 patients who underwent internal spermatic vein embolization sperm parameters were improved. CONCLUSIONS: The present study yielded 2 major findings. Thermography is more sensitive and accurate for the detection of varicocele than Doppler ultrasound and physical examination, and it can be used for screening as a single modality in infertile men. Doppler ultrasound and thermography are complementary and their combined use yields the highest sensitivity and accuracy.

Adult↗

PubMed2004

Leydig cell tumors of the testis: gray scale and color Doppler sonographic appearance.

OBJECTIVE: To determine the gray scale and color Doppler sonographic features of Leydig cell tumors of the testis in a series of patients. METHODS: We retrospectively analyzed the sonographic appearance of 10 proven Leydig cell tumors in 9 patients aged 26 to 47 years. Sonographic features that were reviewed included the size and echogenicity of the tumors, presence of cystic areas or calcifications, and distribution pattern of detectable blood flow on color or power Doppler imaging. RESULTS: The tumors ranged from 0.4 to 3.0 cm in diameter, but most were less than 1.0 cm in diameter. In 1 testis, 2 discrete Leydig cell tumors were found. Nine (90%) of the 10 tumors were homogeneously hypoechoic. Only 1 tumor was isoechoic with the testis. None of the tumors contained calcifications. Of 8 tumors with color Doppler imaging, 7 (88%) showed a characteristic pattern of increased peripheral blood flow, which was either circumferential or punctate. Only 1 tumor was found with internal hypervascularity. CONCLUSIONS: Peripheral hypervascularity in a hypoechoic testicular tumor that has little or no internal color Doppler flow should suggest the possibility of a Leydig cell tumor, and consideration should be given to testicle-sparing surgery.

Adult↗