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Biomedical subjects

I Goldstein

Publications and source records attributed to I Goldstein.

At least 163 records · Page 9Linked to original sources
PubMed1994

Impotence and chronic renal failure: a study of the hemodynamic pathophysiology.

A retrospective multi-institutional study was performed to document and characterize the arterial vascular disease in the hypogastric-cavernous arterial bed and/or veno-occlusive dysfunction of the corpora cavernosa in patients with end stage renal disease. We evaluated 20 impotent patients (mean age 40 +/- 9 years) with chronic renal failure using pharmaco-cavernosometry and pharmacocavernosography (4 also underwent pharmaco-arteriography). Patients were divided into groups based on the treatment (14 with renal transplantation and 6 with hemodialysis or peritoneal dialysis), as well as by history of vascular risk factors (16 with and 4 without risk factors). Of the patients 19 revealed abnormal intracavernous pressure responses to repeated intracavenous injections of vasoactive agents implying vascular disease of the penis. Cavernous artery occlusive disease was found in 78% of the patients. All patients who underwent arteriography had diffuse atherosclerotic disease of the distal penile arteries. Corporeal veno-occlusive dysfunction was found in 90% of the patients, of whom 60% had diffuse pan-cavernous leakage involving the dorsal, cavernous and crural veins, glans penis and corpus spongiosum. This renal failure-associated vascular disease of the penis was found to occur independently of the presence of known systemic atherosclerotic vascular risk factors. Patients who underwent early treatment of the uremia by renal transplantation had vasculogenic impotence only in the case of rejection of the renal transplant, suggesting that early renal transplantation may delay or prevent the development of the penile vasculopathy. The most likely pathophysiology of the vascular impairment includes renal failure-associated atherosclerosis, and renal failure-associated hypoxia changes of the contractile (smooth muscle) and structural (collagen/elastin) components of the erectile tissue. Strategies for future research and clinical therapies are suggested.

Adult↗
PubMed1994

A positive intracavernous injection test implies normal veno-occlusive but not necessarily normal arterial function: a hemodynamic study.

During impotence evaluations a positive intracavernous injection test has been presumed to signify normal erectile hemodynamics. This premise was tested by obtaining hemodynamic data in 80 patients 17 to 65 years old with positive injection tests: patients achieved maximal circumference responses and equilibrium intracavernous pressures of 80 mmHg or more (range 80 to 136) sustained for 30 minutes or longer. Corporeal veno-occlusive testing revealed that flow-to-maintain (0.5 to 3 ml. per minute) and pressure decay (0 to 47 mmHg) values as well as pharmaco-cavernosography findings (absent or minimal contrast medium in venous structures in 92% of the cases) were all consistent with low outflow erection states. Arterial testing revealed right and/or left cavernous systolic arterial blood pressures always at 80 mmHg or more, consistent with a prerequisite cavernous artery pressure value for a positive injection test. Systemic-cavernous systolic arterial blood pressure gradients were 0 to 24 mmHg, 25 to 34 mmHg and 35 mmHg or more in 47 (59%), 18 (22%) and 15 (19%) patients, respectively. Large systemic-cavernous pressure gradients suggested the presence of arterial occlusive disease. In 8 patients with positive injection tests and gradients of 35 mmHg or more pharmaco-arteriography revealed hemodynamically significant arterial occlusions. In conclusion, hemodynamic data in selected patients with positive injection tests revealed low outflow erection states, threshold cavernous artery pressures and disparities in systemic-cavernous systolic pressure gradients that suggested arterial disease in 19% of the cases. The erectile response in a positive test is equal to or greater than a threshold response, not always the maximum response as determined by the systemic blood pressure. A positive intracavernous injection test did not necessarily signify normal erectile hemodynamics.

Adolescent↗
PubMed1994

Preexisting vascular pathology in donor and recipient vessels during penile microvascular arterial bypass surgery.

The quality of the anastomosed vessels before vascular grafting has been shown to influence long-term patency rates in arterial reconstructive procedures. A study was designed to assess vascular graft quality during microvascular artery bypass procedures for impotence, correlate identified vasculopathy with the clinical history and gain insight into vascular pathophysiological mechanisms. A total of 194 donor or recipient vessel segments was biopsied in 111 patients with impotence who underwent microvascular artery bypass surgery during a 10-year period. A prospective histological grading system was used in a blinded randomized fashion. A preexisting vascular pathological condition was identified in 48% of the patients. Proliferative lesions above the internal elastic lamina with luminal stenosis were identified in 38 of 69 dorsal penile artery segments (55%) and 8 of 69 inferior epigastric artery segments (12%). Venous hypertrophy or sclerosis was observed in 13 of 56 deep dorsal vein segments (23%). Systemic atherosclerosis was likely the underlying pathophysiology of vascular disease in the inferior epigastric artery. Vasculopathy in the deep dorsal vein and the dorsal penile artery segments was probably related to the consequences of blunt trauma to the pelvis, perineum or penis, which was considered to occur following direct vessel wall injury with immediate or delayed vascular disease or indirect vessel wall injury secondary to proximal arterial occlusion and delayed distal vascular disease. Future studies are needed to investigate the relationship between preexisting graft vasculopathy in microvascular artery bypass surgery for impotence and long-term clinical success rates.

Adolescent↗
PubMed1994

Arterial priapism: diagnosis, treatment and long-term followup.

We report on the long-term followup of 7 patients 11 to 50 years old treated for arterial priapism following perineal or penile trauma with arteriographic evidence of contrast medium extravasating from a lacerated cavernous artery into surrounding erectile tissue lacunae (an arterial-lacunar fistula). All patients underwent medical record review and completed a mailed questionnaire. The priapism erections were described as devoid of pain or tenderness, incompletely but constantly rigid and able to increase rigidity with sexual stimulation. Bright red corporeal aspirates were observed in all cases. Color flow Doppler ultrasound findings of focal areas of high flow turbulence correlated with diagnostic arteriography (correlation coefficient 1.00). Initial treatment by mechanical or pharmacological means was unsuccessful when performed. Superselective transcatheter embolization of the ipsilateral common penile artery resolved the priapism in all cases. The interval from onset to resolution of priapism was 4 to 126 days. Full erectile function return was delayed from 2 weeks to 5 months, most likely from resolving clot lysis. Full erection quality was restored in 6 of 7 patients with persistent function and restored frequency of intercourse at 6 to 67 months. Reestablished cavernous artery flow in previously embolized arteries was demonstrated on followup ultrasonography. Surgical treatment was not required in any case. We conclude that arterial priapism occurs in the absence of neurogenic-mediated relaxation, and is sustained by high oxygen tension and shear stress associated with the cavernous artery laceration. Embolization therapy offers effective management of the pathophysiology with high preservation of premorbid erectile function.

Adolescent↗
PubMed1994

Impotence.

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Alprostadil↗
PubMed1994

Fetal responses to maternal exercise: effect on fetal breathing and body movement.

This study was conducted to determine the impact of maternal exercise on fetal breathing and fetal body movement, which are commonly used for assessing fetal well-being. Twelve healthy patients with a range of gestational ages of 26 to 36 weeks, who actively exercised throughout pregnancy, participated in the study. The patients walked on a motorized treadmill using a modified Bruce protocol until the maternal heart rate reached 75% of the age-predicted maximal heart rate. Fetal activities (fetal breathing and fetal body movement) were continuously monitored with real-time ultrasonography for 20 minutes before and after the standardized exercise test. Our results demonstrate that there is a significant increase in maternal heart rate and blood pressure associated with exercise. In addition, there is a significant decrease in the total duration and frequency of fetal breathing and fetal body movements following acute maternal exercise.

Adult↗
PubMed1994

Sonographic measurements of the umbilical cord and vessels during normal pregnancies.

Sonographic measurements of the umbilical cord and vessels were performed in 368 uncomplicated pregnancies, and nomograms of their growth were constructed. All measurements were obtained in appropriate for gestational age fetuses in pregnancies with accurate dating. From the above measurements, an estimate of Wharton's jelly quantity (expressed as square millimeters) was calculated. The nomograms presented add another biometric measurement of normally growing fetuses and may serve to differentiate between them and those who are found to have umbilical cord abnormalities.

Adult↗
PubMed1994

Penile ultrasound.

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Erectile Dysfunction↗
PubMed1994

Transabdominal needle embryofetoscopy: a new technique paving the way for early fetal therapy.

OBJECTIVE: To explore the feasibility of using a newly devised needle endoscope to conduct transabdominal first-trimester endoscopy for both embryonic visualization and blood sampling. METHODS: Following informed consent, 12 patients at 8-12 weeks' gestation undergoing first-trimester termination were invited to participate in this study. Transabdominal needle embryofetoscopy was also performed in one continuing pregnancy. A specially designed 16-gauge, double-barrel instrument sheath equipped with 0.8-mm fiberoptic endoscope and a customized 27-gauge heparinized needle were passed transabdominally under ultrasound guidance through the uterine wall and into the exocoelomic space. RESULTS: Using first-trimester transabdominal needle embryofetoscopy, we were able to identify the normal anatomical landmarks of the embryo and were also able to gain access to the embryonic circulation by advancing the 27-gauge needle into the umbilical vessels. In addition, we were able to infuse indigo carmine dye into the fetal circulation of three subjects. Needle embryofetoscopy was also used in a continuing pregnancy for prenatal diagnosis. CONCLUSION: Our experience establishes the feasibility of first-trimester transabdominal needle embryofetoscopy for embryonic visualization and access to the circulation. This new development is expected to serve as a basis for further studies attempting to diagnose and treat congenital diseases in early pregnancy.

Abdomen↗
PubMed1994

The real-time and color Doppler appearance of adrenal neuroblastoma in a third-trimester fetus.

BACKGROUND: Neuroblastoma is the second most common malignant tumor of childhood. With the increasing use of ultrasound, prenatal recognition of this tumor is becoming more common. CASE: A 33-year-old woman presented at 38 weeks' gestation. A mass at the level of the left fetal renal pole was identified upon ultrasonography. Color Doppler and flow mapping were also evaluated. CONCLUSION: Ultrasound evaluation, color flow mapping, and Doppler flow studies of fetal neuroblastoma may be helpful in both diagnosis and management.

Adrenal Gland Neoplasms↗
PubMed1993

Early experience with the first pre-connected 3-piece inflatable penile prosthesis: the Mentor Alpha-1.

The aim of this clinical investigation was to obtain preliminary treatment outcome data concerning the Mentor Alpha-1, the first 3-piece inflatable penile prosthesis with pre-connected tubing between the pump and the penile cylinders. The study was designed to be the first multi-institutional treatment outcome report for any clinically available penile prosthesis with data analysis to be independent of the participating surgeons. A total of 12 board-certified urologists of mixed surgical training backgrounds and practices implanted the Alpha-1 device in 112 consecutive patients. With a mean of 27 +/- 5 months of followup the surgical complication rate included a 4% mechanical malfunction, 2% infection rate and 9% reoperation rate. Patient experience with the implanted device was computed from information on 96 of the 112 patients who returned a questionnaire. Of the patients 82% stated that the device fulfilled expectations as a treatment for impotence and 83% had improved sexual intercourse by 8 weeks after implantation. Patient satisfaction was computed on a scale of 12 equally weighted interrelated variables. Of the patients 77% recorded 9 or more cumulative satisfaction points. Patient and physician questionnaire data were analyzed for their relation to the cumulative prosthesis satisfaction score. A significant difference in cumulative scores was found for physician reported long-term postoperative problems (mean satisfaction score 8.1 for patients with problems versus 10.2 for patients without problems, p = 0.018). The Alpha-1, with its feature of pre-connected tubing, is a reliable 3-piece inflatable penile prosthesis associated with a high level of patient satisfaction.

Data Collection↗
PubMed1993

Intraluminal device pressures in 3-piece inflatable penile prostheses: the "pathophysiology" of mechanical malfunction.

The role of intraluminal device pressure in the development of mechanical failures in 3-piece inflatable penile prostheses was investigated in a 2-part study. An in vitro study was performed in which mean intraluminal device pressures were recorded in Mentor IPP, Mentor Alpha-1, AMS 700 CX and AMS Ultrex devices. At maximum inflated volumes mean intraluminal device pressures exceeded 600 and 1,000 mm. Hg at rest, and 850 and 1,300 mm. Hg following external loading in Mentor and AMS products, respectively. The AMS 700 CX was associated with the highest mean intraluminal device pressure, with values approaching 1,400 mm. Hg following external loading. A 4-year clinical review at our institution was performed comparing the mechanical malfunctions in 51, 3-piece implants with connectors between the pump and cylinders (AMS 700 CX) to the mechanical malfunctions of 50, 3-piece implants with pre-connected tubing between the pump and cylinders (Mentor Alpha-1). Fluid leaks were identified in 16% of the former and 4% of the latter devices. It is proposed that the high intraluminal device pressures are an important factor in the pathophysiology of the mechanical malfunctions in 3-piece inflatable penile prostheses and that connectors are considered components at risk for pressure-associated fluid leaks. The ideal penile prosthesis should maintain the superior rigidity and cosmetic features of the 3-piece inflatable penile prosthesis. However, the device should be pre-connected and designed to mimic more closely the anatomy of the human penis to achieve functional erections at lower intraluminal device pressure values.

Adult↗
PubMed1993

The native venous architecture is preserved in an arterialized deep dorsal vein graft for arteriogenic impotence: a case report.

Endothelial injury in a deep dorsal vein graft may result from thermal, ischemic or mechanical trauma during surgical preparation or following exposure to systemic blood pressures and flow. We removed a functioning in situ deep dorsal vein graft section 10 months after microvascular arterial bypass surgery due to glans hyperemia. This section was compared and contrasted histomorphologically with a preoperative deep dorsal vein section that was procured for routine histological examination before the arteriovenous anastomosis. Detailed examination of the vein graft tissues by light microscopy, computer morphometrics and immunological staining demonstrated no evidence of vascular pathology. In the normal, healthy deep dorsal vein graft exposure to systemic arterial blood pressures and flow for 10 months did not result in myointimal proliferative lesions. Such histological changes seem more likely to be attributable to endothelial injury following iatrogenic surgical trauma. In situ vein grafts offer the opportunity to use "no-touch" endothelium preserving vascular techniques. Use of these grafts may improve long-term clinical results in penile microvascular arterial bypass surgery for impotence as it has in other vascular beds.

Adult↗
PubMed1993

Priapism of the clitoris: a case report following trazodone use.

We report a case of painful priapism of the clitoris lasting 24 hours, which was believed to be pathophysiologically associated with the administration of trazodone hydrochloride. Drug-induced unusual erectile activity in the clitoris has been described previously. However, to our knowledge this is the first reported case of drug-induced priapism of the clitoris. Management involved discontinuation of the offending agents and administration of adrenergic agonists to induce clitoral smooth muscle contraction. Clitoral function, proposed to be the ability to engorge and enable extrusion of the glans clitoris, was not obviously adversely affected by the priapistic episode.

Adjustment Disorders↗
PubMed1993

Oxygen tension regulates the nitric oxide pathway. Physiological role in penile erection.

Relaxation of the trabecular smooth muscle of the corpus cavernosum (the erectile tissue) of the penis is mediated by nitric oxide released by the nerves and endothelium. We have investigated the physiological role of oxygen tension in the regulation of trabecular smooth muscle tone. In human subjects, measurement of intracavernosal PO2 in blood drawn from corpus cavernosum in the flaccid state was comparable to that of venous blood (25-43 mmHg). Vasodilatation of the resistance arteries and trabecular smooth muscle relaxation by intracavernosal injection of papaverine and phentolamine caused oxygen tension to rise rapidly to arterial levels (PO2 approximately 100 mmHg). Isolated human and rabbit corpus cavernosum tissue strips in organ baths, exposed to arterial-like PO2 relaxed to the endothelium-dependent dilator acetylcholine and to electrical stimulation of the autonomic dilator nerves. These nitric oxide-mediated responses were progressively inhibited as a function of decreasing PO2 to levels measured in the flaccid penis. Reverting to normoxic conditions readily restored endothelium-dependent and neurogenic relaxation. Relaxation to exogenous nitric oxide was not impaired in low PO2. In rabbit corpus cavernosum, low PO2 reduced basal levels of cGMP and prevented cGMP accumulation induced by stimulation of dilator nerves. Furthermore, low PO2 inhibited nitric oxide synthase activity in corpus cavernosum cytosol. It is concluded that physiological concentrations of oxygen modulate penile erection by regulating nitric oxide synthesis in corpus cavernosum tissue.

Amino Acid Oxidoreductases↗
PubMed1992

Sonography of fetal Dandy-Walker malformation: a reappraisal.

Thirty-four cases of fetal Dandy-Walker malformation recognized in utero with ultrasound between 16 and 37 weeks' gestation are reported. In each case a qualitative examination of the posterior fossa structures was performed, including the cerebellar hemispheres, cerebellar vermis, fourth ventricle and cisterna magna. In each case, the transverse cerebellar diameter and the depth of the cisterna magna were measured in a standard transcerebellar view of the fetal brain. The atrial width of the lateral ventricles was also assessed. The transverse cerebellar diameter was abnormal in 15 cases, the cisterna magna depth was abnormal in 33, and the atrial width was abnormal in 30. It is concluded that measurement of the transverse cerebellar diameter is unreliable in predicting fetal Dandy-Walker malformation. Measurements of the cisterna magna and atrium seem to be more valuable, although the real sensitivity remains unclear. In pregnancies at risk for fetal Dandy-Walker malformation, the sonographic examination should not be limited to the cerebral ventricles and transcerebellar view but should include a detailed evaluation of all the different anatomical components of the posterior fossa, especially the fourth ventricle and inferior cerebellar vermis.

Journal Article↗