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Elevated Pressure in the Left Renal Vein in Patients with Varicocele: Preliminary Observations
0022-5347 /80/1234-0512$02.00/0 Vol. 123, April
THE JOURNAL OF UROLOGY
Printed in U.S.A.
Copyright © 1980 by The Williams & Wilkins Co.
ELEVATED PRESSURE IN THE LEFT RENAL VEIN IN PATIENTS WITH VARICOCELE: PRELIMINARY OBSERVATIONS ELIAS A. ZERHOUNI,* STANLEY S. SIEGELMAN, PATRICK C. WALSH
AND
ROBERT I. WHITE
From the Russell H. Morgan Department of Radiology and Radiological Science and the James Buchanan Brady Urological Institute, The Johns Hopkins Medical Institutions, Baltimore, Maryland
ABSTRACT
In 3 patients with varicocele a pressure difference was found between the left renal vein and inferior vena cava. No pressure difference was found between the right renal vein and inferior vena cava in these same patients. In a control group of 5 patients right and left renal veins and inferior vena cava pressures closely approximated each other. These preliminary findings are discussed and found to be in disagreement with current concepts of the pathogenesis of varicocele. V aricocele, a pathologic dilatation of the venous circulation of the testes, is a common condition found in up to 9.5 per cent of the adult male population. 1 The demonstration of a definite relationship between varicocele and infertility and subfertility has revived interest in this condition. 2' 3 Multiple postmortem and venographic studies of varicocele have been reported but to our knowledge none has dealt with the in vivo pressure relationships of the left testicular vein, left and right renal veins and the inferior vena cava. We herein present our preliminary results in such a study and their implications in the pathogenesis of varicocele. MATERIAL AND METHODS
The 3 patients with proved varicocele referred to us for preoperative evaluation and 5 patients without varicocele referred for renal vein renin sampling comprise our study group. None of the patients in the control group was age-matched to the 2 younger patients with varicocele. Pressure measurements were obtained with the transducers at the right atrial level and recorded on a standard physiological recorder. Catheterization was done percutaneously through a femoral vein. Pull back tracings were recorded from the left and right renal veins to the inferior vena cava. In 2 patients with varicocele withdrawal measurements were obtained from the left testicular vein to the left renal vein to the inferior vena cava. Pressures were measured with patients in the supine position in all cases except for 1 patient with varicocele in whom measurements were made in the prone position also. In the patients with varicocele measurements were made before and after injection of contrast material in the left testicular vein, except in 1 in whom they were made only after injection. No catheterization of the left testicular vein was attempted in the patients without varicocele. RESULTS
In the varicocele group high left renal vein pressure (23 and 17 mm. Hg) and high left renal vein-inferior vena cava pressure differences (19 and 16 mm. Hg) were found in the 2 younger patients. In the third patient a 4 mm. Hg left renal vein-inferior vena cava pressure difference was found. In the 2 patients in whom left testicular vein pressures were recorded, left testicular vein and left renal vein pressures were equal (table 1). In the non-varicocele group the highest pressure difference was 3 mm. Hg (table 2). Measurements before and after injections of contrast medium showed no changes. In the patient with pressures recorded while he was in the supine and prone positions no significant change was noted between the 2 positions. In 1 Accepted for publication May 11, 1979. * Requests for reprints: Department of Radiology, The Johns Hopkins Hospital, Baltimore, Maryland 21205.
patient with varicocele the pressure tracing in the left renal vein revealed an arterial configuration with systolic and diastolic components reflecting possible compression by an artery (see figure). DISCUSSION
The currently accepted pathophysiologic mechanism of varicocele is one of reflux into the testicular vein with the patient in the erect posture, owing to absence or incompetence of the valves of the spermatic vein. 4 This explanation is not satisfactory because of several inconsistencies. Ahlberg and associates have shown that valves are absent or incompetent in the gonadal veins in 51 per cent of the cases on the left side and in 45 per cent of the cases on the right side. 5 It would be difficult to account for the incidence of only 9.5 per cent ofvaricocele in the adult male population on this basis. If absent or incompetent valves were of sufficient significance the actual incidence of varicocele would be higher. It has been hypothesized that the flow of blood in the left testicular vein is impaired by the flow in the left renal vein because of the right angle junction of the left testicular vein with the left renal vein. This mechanism is invoked by some authors to explain the higher frequency of varicocele on the left side (98 per cent). 6 However, in the low pressure venous system the single most important factor in hydrostatic pressure differences is height difference. Therefore, with the patient in the upright position both testicles are submitted to the same amount of hydrostatic pressure when the valves are incompetent. This is not affected by the angles of junction of the veins. Consequently, the right angle of junction of the left testicular vein to the left renal vein does not account, in our opinion, for the marked predominance of varicoceles on the left side. These considerations and our findings of elevated left renal vein pressure lead us to suggest that compression of the left renal vein in combination with incompetency of testicular vein valves is the probable cause of varicocele formation. We would hypothesize that there is reversed flow in the left testicular vein in cases of varicocele with blood flowing from the left renal vein into the left testicular vein because of a pressure gradient between the left renal vein and the inferior vena cava. We have not been able to demonstrate the cause of the abnormal pressure gradient in our cases but other investigators have mentioned 3 possible anatomical causes based on autopsy studies. Fagarasanu reported on the compression of the left renal vein between the aorta and the superior mesenteric artery in association with varicocele. He also mentioned the possible role of the ligament of Treitz in compression of the left renal vein. 7 In 1 case of varicocele N otkovich demonstrated that the testicular artery arched over and compressed the left renal vein. 8 Our finding of an arterial configuration to the left renal
512
ELEVATED PRESSURE IN LEFT RENAL VEIN IN PATIENTS WITH VARICOCELE TABLE
1. Varicocele group: pressures (mm. Hg)
Age Pt. No.-(yrs.)
Lt. Testicular Vein
Rt. Renal Vein
Lt. Renal Vein
1-15 2-16 3-34
23 19
6 3 11
23 19 15
Not done TABLE
Lt. Renal Inferior VeinVena Inferior Cava Vena Cava Difference 6 3 11
17 16 4
2. Control group: pressures (mm. Hg)
Age Pt. No.-(yrs.)
Rt. Renal Vein
Lt. Renal
1-38 2-04 3-52 4-29 5-39
10 9 12 10 8
12 10 13 13 11
Vein
Inferior Vena Cava
Lt. Renal VeinInferior Vena Cava Difference
11 10 12
0
10
9
1 1 3 2
EKG
513
pattern of body development are other possible factors that may explain the appearance of varicocele only at puberty. We propose that in patients with varicocele there is an abnormal pressure gradient between the left renal vein and inferior vena cava probably owing to anatomical factors. Consequently, the collateral venous pathways of the left renal vein develop, one of which is through the left testicular venous plexus. It is probable that in our older patient a low pressure gradient was observed because decompression of the left renal vein through its collaterals had occurred already. The eventual decompression of the left renal vein through collateral channels would explain the results of Sayfan and Adam in which no elevation of the left testicular vein pressure was noted in patients with varicocele. 9 In their study age was not mentioned. The valves of the spermatic veins are absent or incompetent as they are in a large percentage of the normal population and probably have no primary role in the pathogenesis ofvaricocele. Further investigations are needed to confirm these preliminary findings and possibly identify their cause(s), which may alter the management of these patients at high risk for infertility problems. REFERENCES 1. Johnson, D. E., Pohl, D. R. and Rivera-Correa, H.: Varicocele: an innocuous condition? South. Med. J., 63: 34, 1970.
30
c,,
20
I
E E
10
Patient 1. Pressure recording during catheter withdrawal from left renal vein (LRV) to inferior vena cava (IVC). Note arterial dynamics of pressure in left renal vein and sharp decrease in pressure as catheter passes into inferior vena cava.
vein pressure in 1 patient would support the concept of compression of the left renal vein by an artery as significant in the etiology of the varicocele in this patient. Perhaps any combination of the 3 previously mentioned possibilities for compression of the left renal vein may be important in the individual patient. These fixed anatomical configurations alone do not explain why varicocele usually appears during adolescence and not before. Body habitus, amount of retroperitoneal fat and
2. Charny, C. W.: Effect of varicocele on fertility. Results of varicocelectomy. Fertil. Steril., 13: 47, 1962. 3. Dubin, L. and Amelar, R. D.: Etiologic factors in 1294 consecutive cases of male infertility. Fertil. Steril., 22: 469, 1971. 4. Glezerman, M., Rakowszczyk, M., Lunenfeld, B., Beer, R. and Goldman, B.: Varicocele in oligospermic patients: pathophysiology and results after ligation and division of the internal spermatic vein. J. Urol., 115: 562, 1976. 5. Ahlberg, N. E., Bartley, 0. and Chidekel, M.: Right and left gonadal veins. An anatomical and statistical study. Acta Rad. [Diagn.] (Stockholm), 4: 593, 1966. 6. Brown, J. S., Dubin, L. and Hotchkiss, R. S.: The varicocele as related to fertility. Fertil. Steril., 18: 46, 1967. 7. Fagarasanu, I.: Recherches Anatomiques sur la veine renale gauche et ses collaterales, leurs rapports avec la pathogenie du varicocele essentiel et des varices du ligament large. Ann. Anat. Path., 15: 9, 1938. 8. Notkovich, H.: Testicular artery arching over renal vein: clinical and pathological considerations with special reference to varicocele. Brit. J. Urol., 27: 267, 1955. 9. Sayfan, J. and Adam, Y. G.: Varicocele subfertility and venous pressure in the left internal spermatic vein. Fertil. Steril., 29: 366, 1978.
THE JOURNAL OF UROLOGY
Printed in U.S.A.
Copyright © 1980 by The Williams & Wilkins Co.
ELEVATED PRESSURE IN THE LEFT RENAL VEIN IN PATIENTS WITH VARICOCELE: PRELIMINARY OBSERVATIONS ELIAS A. ZERHOUNI,* STANLEY S. SIEGELMAN, PATRICK C. WALSH
AND
ROBERT I. WHITE
From the Russell H. Morgan Department of Radiology and Radiological Science and the James Buchanan Brady Urological Institute, The Johns Hopkins Medical Institutions, Baltimore, Maryland
ABSTRACT
In 3 patients with varicocele a pressure difference was found between the left renal vein and inferior vena cava. No pressure difference was found between the right renal vein and inferior vena cava in these same patients. In a control group of 5 patients right and left renal veins and inferior vena cava pressures closely approximated each other. These preliminary findings are discussed and found to be in disagreement with current concepts of the pathogenesis of varicocele. V aricocele, a pathologic dilatation of the venous circulation of the testes, is a common condition found in up to 9.5 per cent of the adult male population. 1 The demonstration of a definite relationship between varicocele and infertility and subfertility has revived interest in this condition. 2' 3 Multiple postmortem and venographic studies of varicocele have been reported but to our knowledge none has dealt with the in vivo pressure relationships of the left testicular vein, left and right renal veins and the inferior vena cava. We herein present our preliminary results in such a study and their implications in the pathogenesis of varicocele. MATERIAL AND METHODS
The 3 patients with proved varicocele referred to us for preoperative evaluation and 5 patients without varicocele referred for renal vein renin sampling comprise our study group. None of the patients in the control group was age-matched to the 2 younger patients with varicocele. Pressure measurements were obtained with the transducers at the right atrial level and recorded on a standard physiological recorder. Catheterization was done percutaneously through a femoral vein. Pull back tracings were recorded from the left and right renal veins to the inferior vena cava. In 2 patients with varicocele withdrawal measurements were obtained from the left testicular vein to the left renal vein to the inferior vena cava. Pressures were measured with patients in the supine position in all cases except for 1 patient with varicocele in whom measurements were made in the prone position also. In the patients with varicocele measurements were made before and after injection of contrast material in the left testicular vein, except in 1 in whom they were made only after injection. No catheterization of the left testicular vein was attempted in the patients without varicocele. RESULTS
In the varicocele group high left renal vein pressure (23 and 17 mm. Hg) and high left renal vein-inferior vena cava pressure differences (19 and 16 mm. Hg) were found in the 2 younger patients. In the third patient a 4 mm. Hg left renal vein-inferior vena cava pressure difference was found. In the 2 patients in whom left testicular vein pressures were recorded, left testicular vein and left renal vein pressures were equal (table 1). In the non-varicocele group the highest pressure difference was 3 mm. Hg (table 2). Measurements before and after injections of contrast medium showed no changes. In the patient with pressures recorded while he was in the supine and prone positions no significant change was noted between the 2 positions. In 1 Accepted for publication May 11, 1979. * Requests for reprints: Department of Radiology, The Johns Hopkins Hospital, Baltimore, Maryland 21205.
patient with varicocele the pressure tracing in the left renal vein revealed an arterial configuration with systolic and diastolic components reflecting possible compression by an artery (see figure). DISCUSSION
The currently accepted pathophysiologic mechanism of varicocele is one of reflux into the testicular vein with the patient in the erect posture, owing to absence or incompetence of the valves of the spermatic vein. 4 This explanation is not satisfactory because of several inconsistencies. Ahlberg and associates have shown that valves are absent or incompetent in the gonadal veins in 51 per cent of the cases on the left side and in 45 per cent of the cases on the right side. 5 It would be difficult to account for the incidence of only 9.5 per cent ofvaricocele in the adult male population on this basis. If absent or incompetent valves were of sufficient significance the actual incidence of varicocele would be higher. It has been hypothesized that the flow of blood in the left testicular vein is impaired by the flow in the left renal vein because of the right angle junction of the left testicular vein with the left renal vein. This mechanism is invoked by some authors to explain the higher frequency of varicocele on the left side (98 per cent). 6 However, in the low pressure venous system the single most important factor in hydrostatic pressure differences is height difference. Therefore, with the patient in the upright position both testicles are submitted to the same amount of hydrostatic pressure when the valves are incompetent. This is not affected by the angles of junction of the veins. Consequently, the right angle of junction of the left testicular vein to the left renal vein does not account, in our opinion, for the marked predominance of varicoceles on the left side. These considerations and our findings of elevated left renal vein pressure lead us to suggest that compression of the left renal vein in combination with incompetency of testicular vein valves is the probable cause of varicocele formation. We would hypothesize that there is reversed flow in the left testicular vein in cases of varicocele with blood flowing from the left renal vein into the left testicular vein because of a pressure gradient between the left renal vein and the inferior vena cava. We have not been able to demonstrate the cause of the abnormal pressure gradient in our cases but other investigators have mentioned 3 possible anatomical causes based on autopsy studies. Fagarasanu reported on the compression of the left renal vein between the aorta and the superior mesenteric artery in association with varicocele. He also mentioned the possible role of the ligament of Treitz in compression of the left renal vein. 7 In 1 case of varicocele N otkovich demonstrated that the testicular artery arched over and compressed the left renal vein. 8 Our finding of an arterial configuration to the left renal
512
ELEVATED PRESSURE IN LEFT RENAL VEIN IN PATIENTS WITH VARICOCELE TABLE
1. Varicocele group: pressures (mm. Hg)
Age Pt. No.-(yrs.)
Lt. Testicular Vein
Rt. Renal Vein
Lt. Renal Vein
1-15 2-16 3-34
23 19
6 3 11
23 19 15
Not done TABLE
Lt. Renal Inferior VeinVena Inferior Cava Vena Cava Difference 6 3 11
17 16 4
2. Control group: pressures (mm. Hg)
Age Pt. No.-(yrs.)
Rt. Renal Vein
Lt. Renal
1-38 2-04 3-52 4-29 5-39
10 9 12 10 8
12 10 13 13 11
Vein
Inferior Vena Cava
Lt. Renal VeinInferior Vena Cava Difference
11 10 12
0
10
9
1 1 3 2
EKG
513
pattern of body development are other possible factors that may explain the appearance of varicocele only at puberty. We propose that in patients with varicocele there is an abnormal pressure gradient between the left renal vein and inferior vena cava probably owing to anatomical factors. Consequently, the collateral venous pathways of the left renal vein develop, one of which is through the left testicular venous plexus. It is probable that in our older patient a low pressure gradient was observed because decompression of the left renal vein through its collaterals had occurred already. The eventual decompression of the left renal vein through collateral channels would explain the results of Sayfan and Adam in which no elevation of the left testicular vein pressure was noted in patients with varicocele. 9 In their study age was not mentioned. The valves of the spermatic veins are absent or incompetent as they are in a large percentage of the normal population and probably have no primary role in the pathogenesis ofvaricocele. Further investigations are needed to confirm these preliminary findings and possibly identify their cause(s), which may alter the management of these patients at high risk for infertility problems. REFERENCES 1. Johnson, D. E., Pohl, D. R. and Rivera-Correa, H.: Varicocele: an innocuous condition? South. Med. J., 63: 34, 1970.
30
c,,
20
I
E E
10
Patient 1. Pressure recording during catheter withdrawal from left renal vein (LRV) to inferior vena cava (IVC). Note arterial dynamics of pressure in left renal vein and sharp decrease in pressure as catheter passes into inferior vena cava.
vein pressure in 1 patient would support the concept of compression of the left renal vein by an artery as significant in the etiology of the varicocele in this patient. Perhaps any combination of the 3 previously mentioned possibilities for compression of the left renal vein may be important in the individual patient. These fixed anatomical configurations alone do not explain why varicocele usually appears during adolescence and not before. Body habitus, amount of retroperitoneal fat and
2. Charny, C. W.: Effect of varicocele on fertility. Results of varicocelectomy. Fertil. Steril., 13: 47, 1962. 3. Dubin, L. and Amelar, R. D.: Etiologic factors in 1294 consecutive cases of male infertility. Fertil. Steril., 22: 469, 1971. 4. Glezerman, M., Rakowszczyk, M., Lunenfeld, B., Beer, R. and Goldman, B.: Varicocele in oligospermic patients: pathophysiology and results after ligation and division of the internal spermatic vein. J. Urol., 115: 562, 1976. 5. Ahlberg, N. E., Bartley, 0. and Chidekel, M.: Right and left gonadal veins. An anatomical and statistical study. Acta Rad. [Diagn.] (Stockholm), 4: 593, 1966. 6. Brown, J. S., Dubin, L. and Hotchkiss, R. S.: The varicocele as related to fertility. Fertil. Steril., 18: 46, 1967. 7. Fagarasanu, I.: Recherches Anatomiques sur la veine renale gauche et ses collaterales, leurs rapports avec la pathogenie du varicocele essentiel et des varices du ligament large. Ann. Anat. Path., 15: 9, 1938. 8. Notkovich, H.: Testicular artery arching over renal vein: clinical and pathological considerations with special reference to varicocele. Brit. J. Urol., 27: 267, 1955. 9. Sayfan, J. and Adam, Y. G.: Varicocele subfertility and venous pressure in the left internal spermatic vein. Fertil. Steril., 29: 366, 1978.