Yigal Gat
Rabin Medical Center
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Featured researches published by Yigal Gat.
Urology | 2003
Yigal Gat; Zvi Zukerman; Gil N. Bachar; Dov Feldberg; Michael Gornish
OBJECTIVES To evaluate the incidence of left and right varicocele in adolescents. METHODS The study group consisted of 28 adolescents who underwent evaluation for varicocele at our clinic. In 19 patients, varicocele was detected on routine physical examination, and 9 patients presented with scrotal pain or discomfort. All patients were evaluated by three methods. Physical examination was followed in all cases by contact thermography and venography studies of both testes. RESULTS The rate of left and right retrograde flow in the spermatic veins by the three methods used was as follows: physical examination 92.8% and 10.7%; contact thermography 100% and 89%; and venography 100% and 85.7%, respectively. Varicocele was not detected by physical examination in 2 (7.2%) of the 28 patients on the left side and in 21 (87.5%) of 24 on the right side. CONCLUSIONS The main finding of this study was that varicocele is a bilateral disease in 85.7% of adolescents. The high percentage of bilateral varicocele in our sample may explain the pathophysiologic mechanism whereby what has traditionally been considered a unilateral disease can produce bilateral testicular dysfunction. The high incidence of subclinical bilateral varicocele may indicate that we should consider varicocele a bilateral disease. The second finding was that only 10% of patients with right varicocele were diagnosed by physical examination and more than 85% were diagnosed by thermography, with confirmation by venography. Therefore, we suggest that thermography and venography should play a major role in the diagnosis of varicocele.
Reproductive Biomedicine Online | 2006
Yigal Gat; Michael Gornish; Uri Navon; Joana Chakraborty; Gil N. Bachar; Izhar Ben-Shlomo
Varicocele is considered a predominantly unilateral left-sided disease. However, since male fertility is preserved with only one healthy testis, infertility perforce represents bilateral testicular dysfunction. It was hypothesized that: (i) right varicocele cannot be diagnosed by palpation and therefore has not been treated in the past by the traditional treatment, and (ii) right varicocele causes impaired oxygen supply in the right testicular microcirculation, leading to germ cell degeneration. This study performed venographies of both right and left internal spermatic veins during the treatment of 840 infertile men with varicocele and analysed the results using tools of fluid mechanics. Histopathology of the right testis revealed stagnation of blood flow and degenerative changes attributed to lack of adequate oxygenation in all testicular cell types. Right varicocele was found in the vast majority of the patients. We found that due to the destruction of one-way valves, pathologic hydrostatic pressure is produced in the testicular venous microcirculatory system about five times higher than normal, exceeding arteriolar pressure. The pressure gradient between the arterioles and venules in the testicular tissue is therefore reversed, leading to persistent hypoxia. Right varicocele, although undetected, is prevalent in infertile men with varicocele, hence only bilateral occlusion of the internal spermatic veins, including the associated bypasses, eliminating the pathologic hydrostatic pressure will lead to resumption of arterial blood flow in the testicular microcirculation.
CardioVascular and Interventional Radiology | 2006
Yoel Siegel; Yigal Gat; Gil N. Bacher; Michael Gornish
PurposeTo classify the anatomic types of the right internal spermatic vein (ISV).MethodsWe evaluated venograms obtained in 150 consecutive patients with idiopathic varicocele referred for transfemoral sclerotherapy.ResultsSix anatomic types of the right internal spermatic vein (ISV) were recognized. These were classified by the location of their orifices and the tributary venous patterns. In roughly half the patients (53%), the ISV appeared as a simple vein with no remarkable retroperitoneal interconnections. In the remainder, complex retroperitoneal anastomoses were encountered.ConclusionBy understanding these anatomic variations, the angiographer can approach treatment of right-sided varicocele with foreknowledge of the nature of these types and the presence of valves and collaterals.
CardioVascular and Interventional Radiology | 2008
Michael Gornish; Yigal Gat; Yoel Siegel
We commend Dr. Iaccarino on his extensive experience with treating varicocele. We agree that sclerotherapy is the most effective way of treating the main internal spermatic vein (ISV) and assuring that the ever-present collaterals are also sclerosed, reducing recurrences. Retrograde (transcatheter) transfemoral sclerotherapy in experienced hands is both safe and efficacious, with none of the theoretical complications suggested by Dr. Iaccarino. We do not heparinize our patients, who are mobilized within 30 min of the completion of their treatment and told not to lie in bed after the first 4 h. We have seen no cases of clinical symptoms of thromboembolism, either systemic or portal. (We are somewhat surprised at such a case: Does Dr. Iaccarino have one?) It might be expected in esophageal varices sclerotherapy, but the amounts of sclerosant that we use and the sclerosing characteristics of 3% sodium tetradecyl sulfate are such that this is not a consideration. We disagree with Dr. Iaccarino about the treatment of so-called subclinical varicocele. We have shown in several of our articles that the physical (hydrodynamic) principles which explain the pathophysiology of varicocele require only that there be incompetent ISV valves for the abnormally high venous pressures to be directly transmitted to the testicular microcirculation and interfere with normal perfusion of the testicular parenchyma. The result is hypoxia of the testicular tissue and this has been shown on histopathology of varicocele (also cited in our articles in the References section of our original paper: CVIR, Vol. 29, No. 2, 192– 197, 2006). The presence of varicocele on the right cannot be reliably demonstrated clinically by Valsalva maneuver because of the hydrodynamics of the right ISV: specifically, its direct emptying into the inferior vena cava (IVC). It is not possible to adequately distend the IVC during Valsalva and elevate pressures for a prolonged time without nearly arresting venous return to the heart and causing very rapid syncope. At the same time, the angle between the ISV and the IVC is acute, and the changes in the relationship between these two venous structures during Valsalva maneuver act to close that angle and decrease flow. Only in those patients with direct emptying of the right ISV into the right renal vein (about 8% in our study), in which the configuration nearly mirrors the left anatomy, can this maneuver be relied on to result in reflux. And again, reflux does not have to be massive (as Dr. Iaccarino proposes) for it to cause infertility. We have (as have others using microsurgical techniques) shown a small but significant group of responders to bilateral sclerotherapy in patients with Sertoli cell only. Dr. Iaccarino cites Dr. Nagler’s comments in the Journal of Urology (2004), in which he questions whether treatment is at all effective. This is in keeping with the multicenter study which showed poor results for ISV occlusions—surgical and interventional techniques. Our response to Dr. Nagler was that we agree that the treatment of varicocele as described by the various authorities was not effective (more than medical treatment), but not because varicocele does not affect fertility: rather, because the treatments were essentially inadequate, ignoring the physical basis for the pathophysiology and the presence of significant venous reflux on the right, not just by interscrotal collaterals. M. Gornish (&) Y. Gat Y. Siegel Department of Radiology, Maayanei Hayeshua Medical Center, Bnei Brak, Israel e-mail: [email protected]
Fertility and Sterility | 2004
Yigal Gat; Gil N. Bachar; Zvi Zukerman; Alexander Belenky; Michael Gornish
Human Reproduction | 2005
Yigal Gat; Zvi Zukerman; Joana Chakraborty; Michael Gornish
Human Reproduction | 2005
Yigal Gat; Gil N. Bachar; Karel Everaert; Uriel Levinger; Michael Gornish
The Journal of Urology | 2004
Yigal Gat; Gil N. Bachar; Zvi Zukerman; Alexander Belenky; Michael Gorenish
Israel Medical Association Journal | 2003
Gil N. Bachar; Alexander Belenky; Franklin Greif; Eli Atar; Yigal Gat; Maxim Itkin; Anthony Verstanding
Human Reproduction | 2004
Yigal Gat; Michael Gornish; Alexander Belenky; Gil N. Bachar