- Email: [email protected]
Blood Gases and pH Determinations in the Internal Spermatic Veins of Subfertile Men with Varicocele
Blood Gases and pH Determinations in the Internal Spermatic Veins of Subfertile Men with Varicocele ROBERT E. DONOHUE, M.D., and JORDAN S. BROWN, M.D.
may impair spermatogenesis. The surgical correction of varicocele often improves semen quality. Tulloch in 1952 first reported the restoration of fertility following varicocelectomy. More recently MacLeod and others2 have documented benefit from this type of surgery. Varicocele is the result of the retrograde flow of venous blood from the renal vein down the internal spermatic vein into the circulation of both testes. To accommodate this increased volume of blood, the veins of the testis become varicosed. The mechanism by which the varicocele impairs the .spermatogenic function has not been ascertained; however, the following possible mechanisms have been suggested: 1. Stasis resulting in tissue destruction very much like that seen in varicose veins of the legs. 2. Abnormalities of the thermoregulatory mechanism. 4 3. The retrograde passage of toxic, metabolic, or endocrine substance from the kidney or adrenal gland into the circulation of the testis. 5 4. Stasis of blood with decreased oxygen tension with poor tissue oxygenation.3
VARICOCELE
Blood gas and pH measurements were .secured in the internal spermatic vein and femoral vein in subfertile patients with varicocele, in an attempt to evaluate the possibility of altered gas content or pH as a cause of spermatogenic depression.
METHOD The subjects were 26 subfertile males with varicocele between the ages of 28 and 45 who, at the time of varicocelectomy, had their internal sperFrom the Department of Urology, New York University Medical Center, New York, N. Y.
365
366
DoNOHUE
&
BRowN
FERTILITY
& STERILITY
matic veins isolated above the internal inguinal ring according to the technique of Palomo. The vein was cannulated with a No. 16 angiocath for a distance of 4 em. in the direction of the kidney and subsequently in the direction of the testis, and the blood pH, P0 2 , and PC0 2 of the specimens were determined. Lastly a specimen of blood was collected from the femoral vein for the same determinations. The determinations were also performed on 1 man, presumably fertile, who did not have a varicocele when he underwent inguinal herniorrhaphy. The operation was performed under general anesthesia while the patient was receiving optimum oxygenation. The table was tilted accordingly to facilitate the collection of· the blood samples and the pH, P0 2 , and PC02 determinations were made within 10 min. of collection, on volumes of 3--5 cc. All measurements were made with the Instrumentation Laboratory Micro pH and blood gas analyzing system.* Attempts to secure specimens of the internal spermatic vein blood from the direction of the testis of sufficient quantity to allow the determinations to be made were not uniformly successful. In 7 of the 26 patients we were unable to secure an adequate sample for the pH, P0 2 , and PC0 2 studies. No difficulty was encountered in obtaining the blood from the direction of the renal vein or the femoral vein. RESULTS
The pH values of the blood obtained from the internal spermatic vein from the kidney are shown in Table 1. The values ranged from 7.23 to 7.45, with a mean value of 7.32. Similar determinations for the blood from the same vein secured in the direction of the testis were pH 7.16-7.35, with a mean of 7.27 (Table 1). The femoral vein pH range was from 7.20 to 7.42, with a mean of 7.33 (Table 1). The PC02 in the internal spermatic vein from the direction of the kidney revealed values of 35-68 mm. Hg, with a mean of 47 (Table 2). In the 21 patients from whom we successfully secured the specimens in the direction of the testis the range was 43-84 mm. Hg, with a mean of 53 (Table 2). The femoral vein values were 37-59 mm. Hg, with a mean of 47 (Table 2). The blood withdrawn from the internal spermatic vein in the direction of *Instrumentation Laboratories, Boston, Mass.
VoL. 20, No. 2, 1969
BLOOD GASES AND
PH
IN VARICOCELE
367
TABLE 1. pH, P02 and PC02 Values in 26 Subfertile Men with Varicocele Internal spermatic vein Direction: kidney Case
1 2 3 4 5 6 7 8 9 10 11
12 13 14 15 16 17 18 19 20
21 22
23 24 25 26
Patient
pH
7.29 7.39 7.34 7.28 7.32 7.30 7.35 7.30 7.39 7.26 7.30 7.30 7.28 7.30 7.23 7.27 7.38 7.30 7.36 7.45 7.25 7.45 7.25 7.32 7.30 7.33 7.34 7.36
H.C. M.E. M.R. R.R. D.J.
L.T. P.M. A.R. E. D.
c.c. D.C. V.D. R.Q. R.R. (L) (R) A.K. J.B. C.R. R.B. (L) (R) A.l. R.B. R.S. J.B. W.K. B.D. B.R. W.K.
PO,
Direction: testis
Femoral vein
PCO,
pH
PO,
PCO,
pH
PO,
PCO.
63 36 48 55 41 47 41 51 50 46
7.27
44
57
7.34 7.37 7.37 7.30 7.27 7.35 7.32 7.32 7.27 7.35 7.27 7.28 7.26 7.31 7.20 7.31 7.37 7.30 7.38 7.42 7.28 7.42 7.30 7.36 7.38 7.31 7.32 7.35
49 87 58 47 64 65 50 48 38 67 52
59 38 45 52 46
83 76 88 48 71
80 83 71
105 80 104 72 62
50
36 58 47 53 44 53 48
68 81 83 101 92 57 73 57 78 83
73 7.28 7.31 7.26 7.27 7.27 7.23 7.16 7.27 7.30 7.21 7.25 7.31 7.28
40
35 46 35 62 47 49 54 39 50
60
105 64 66
7.24 7.30 7.33 7.35 7.31 7.29 7.34
36
50
58
60
47 61 33 48 50
4 78 72 84 41 62 51 53 57 53 35 46 39 35
57 50
55 60 47 58 43 47 68 59 52 35 52 35 59 47 55
65
54
55
54
60
36 76 45 48 77 45 45 39 41 57 73 53 55 36 46
50 50
41 53 39 56 49 42 54 38 58 50 50 44
44 46 37 54 46 46 38 48 52
TABLE 2. Summary of Values Obtained pH
Internal spermatic vein Direction: kidney Direction: testis Femoral vein
P02
PCO,
Range
Mean
Range
Mean
Range
Mean
7.23-7.45 7.16-7.35 7.26-7.42
7.32 7.27 7.33
48-105 35-84 33-87
77 55 53
35-68 43-84 37-59
47 53 47
368
DONOHUE
& BROWN
FERTILITY
& STERILITY
the renal vein had a P02 range of 48-105 mm. Hg, with a mean of 77 (Table 2). The internal spermatic vein specimens taken from the direction of the testis showed measurements of P02 from 35 to 84 mm. Hg, with a mean of 55 (Table 2). The femoral vein values for P02 were from 33 to 87 mm. Hg, with a mean of 53 (Table 2). Specimens of blood secured in the same manner from the patient without clinical varicocele at the time of the repair of his hernia revealed the following: In the sample from the internal spermatic vein in the direction of the kidney, the values were: pH, 7.38; P0 2 , 68 mm. Hg; and PC0 2 , 34 mm. Hg; in the sample from the internal spermatic vein in the direction of the testis, they were: pH, 7.31; P02 , 49 mm. Hg; and PC0 2 , 34 mm. Hg. The femoral vein values were: pH, 7.38; P02 , 42 mm. Hg; and PC0 2 , 55 mm. Hg. DISCUSSION
Under normal physiologic conditions the kidneys receive approximately 25% of the cardiac output. As a result, the oxygen requirements of the kidneys are greatly exceeded by the amounts available and therefore there is a lower oxygen extraction ratio per unit volume of arterial blood, resulting in higher tensions of oxygen in the venous system of the kidney. The renal vein has the highest venous oxygen tension-P0 2 -in the systemic circulation. This is exceeded only by the pulmonary veins which are unique in that they return arterial blood to the heart. The postulation that varicocele impairs fertility by resulting in venous stasis and decreased tissue oxygenation is being challenged. It has heen suggested on the basis of this continuing study that the testis is being bathed in venous blood from the renal vein, a vein whose oxygen tension exceeds that of any other systemic vein and probably approaches arterial tensions. The varicocele may not be decreasing the oxygen tension in the venous plexus of the testis, but may in effect be increasing it. Whether increasing oxygen tension can be in itself deleterious has not been studied at this time. Ahlberg et al. have reported that 50% of all men have retrograde flow. Most of these men do not have varicocele. We believe that the elevated P0 2 in the internal spermatic vein in the 1 control patient studied to date is attributable to retrograde flow. This is probably the only way to account for the discrepancy in the oxygen tensions obtained from the same vein.
VoL. 20, No.2, 1969
BLOOD GAsEs AND PH IN VARICOCELE
369
SUMMARY
The blood pH, P02 , and PC02 were studied in 26 subfertile men with varicocele at the time of varicocelectomy. No significant differences were noted in the pH and PC02 values between the blood in the direction of the kidney and that in the direction of the testis. The internal spermatic vein blood withdrawn from the direction of the renal vein has oxygen tension increased over that of the blood withdrawn from the direction of the testis as well as from the femoral vein blood of these patients. This would tend to minimize the role of hypoxia as a mechanism by which varicocele could impair .spermatogenesis. New York University Medical Center 550 First .4.ve. New York, N.Y. 10016
REFERENCES 1. AHLBERG, N. E., BARTLEY, 0., CHIDEKEL, N., and FRITJOFSON, A. Phlebography in varicocele scroti. Acta Radiol 4:517, 1966. 2. BROWN, J., HOTcHKiss, R., and DUBIN, L. The varicocele as related to fertility. Fertil Steril18:46, 1967. 3. CHARNY, C. W. Effect of varicocele on fertility. Fertil Steril16:135, 1966. 4. DAVIDSON, H. A. Testicular temperature and varicocele. Practitioner 173:703, 1954. 5. MAcLEOD, J. Seminal cytology in the presence of varicocele. Fertil Steril 16:735, 1966. 6. PALOMO, A. Radical cure of varicocele by a new technique. I Urol 61:604, 1949. 7. TULLOCH, W. S. Consideration of sterility. Subfertility in male. (Trans. Edinburgh Obstet Soc). Edinburgh Med I 59:29, 1952.
may impair spermatogenesis. The surgical correction of varicocele often improves semen quality. Tulloch in 1952 first reported the restoration of fertility following varicocelectomy. More recently MacLeod and others2 have documented benefit from this type of surgery. Varicocele is the result of the retrograde flow of venous blood from the renal vein down the internal spermatic vein into the circulation of both testes. To accommodate this increased volume of blood, the veins of the testis become varicosed. The mechanism by which the varicocele impairs the .spermatogenic function has not been ascertained; however, the following possible mechanisms have been suggested: 1. Stasis resulting in tissue destruction very much like that seen in varicose veins of the legs. 2. Abnormalities of the thermoregulatory mechanism. 4 3. The retrograde passage of toxic, metabolic, or endocrine substance from the kidney or adrenal gland into the circulation of the testis. 5 4. Stasis of blood with decreased oxygen tension with poor tissue oxygenation.3
VARICOCELE
Blood gas and pH measurements were .secured in the internal spermatic vein and femoral vein in subfertile patients with varicocele, in an attempt to evaluate the possibility of altered gas content or pH as a cause of spermatogenic depression.
METHOD The subjects were 26 subfertile males with varicocele between the ages of 28 and 45 who, at the time of varicocelectomy, had their internal sperFrom the Department of Urology, New York University Medical Center, New York, N. Y.
365
366
DoNOHUE
&
BRowN
FERTILITY
& STERILITY
matic veins isolated above the internal inguinal ring according to the technique of Palomo. The vein was cannulated with a No. 16 angiocath for a distance of 4 em. in the direction of the kidney and subsequently in the direction of the testis, and the blood pH, P0 2 , and PC0 2 of the specimens were determined. Lastly a specimen of blood was collected from the femoral vein for the same determinations. The determinations were also performed on 1 man, presumably fertile, who did not have a varicocele when he underwent inguinal herniorrhaphy. The operation was performed under general anesthesia while the patient was receiving optimum oxygenation. The table was tilted accordingly to facilitate the collection of· the blood samples and the pH, P0 2 , and PC02 determinations were made within 10 min. of collection, on volumes of 3--5 cc. All measurements were made with the Instrumentation Laboratory Micro pH and blood gas analyzing system.* Attempts to secure specimens of the internal spermatic vein blood from the direction of the testis of sufficient quantity to allow the determinations to be made were not uniformly successful. In 7 of the 26 patients we were unable to secure an adequate sample for the pH, P0 2 , and PC0 2 studies. No difficulty was encountered in obtaining the blood from the direction of the renal vein or the femoral vein. RESULTS
The pH values of the blood obtained from the internal spermatic vein from the kidney are shown in Table 1. The values ranged from 7.23 to 7.45, with a mean value of 7.32. Similar determinations for the blood from the same vein secured in the direction of the testis were pH 7.16-7.35, with a mean of 7.27 (Table 1). The femoral vein pH range was from 7.20 to 7.42, with a mean of 7.33 (Table 1). The PC02 in the internal spermatic vein from the direction of the kidney revealed values of 35-68 mm. Hg, with a mean of 47 (Table 2). In the 21 patients from whom we successfully secured the specimens in the direction of the testis the range was 43-84 mm. Hg, with a mean of 53 (Table 2). The femoral vein values were 37-59 mm. Hg, with a mean of 47 (Table 2). The blood withdrawn from the internal spermatic vein in the direction of *Instrumentation Laboratories, Boston, Mass.
VoL. 20, No. 2, 1969
BLOOD GASES AND
PH
IN VARICOCELE
367
TABLE 1. pH, P02 and PC02 Values in 26 Subfertile Men with Varicocele Internal spermatic vein Direction: kidney Case
1 2 3 4 5 6 7 8 9 10 11
12 13 14 15 16 17 18 19 20
21 22
23 24 25 26
Patient
pH
7.29 7.39 7.34 7.28 7.32 7.30 7.35 7.30 7.39 7.26 7.30 7.30 7.28 7.30 7.23 7.27 7.38 7.30 7.36 7.45 7.25 7.45 7.25 7.32 7.30 7.33 7.34 7.36
H.C. M.E. M.R. R.R. D.J.
L.T. P.M. A.R. E. D.
c.c. D.C. V.D. R.Q. R.R. (L) (R) A.K. J.B. C.R. R.B. (L) (R) A.l. R.B. R.S. J.B. W.K. B.D. B.R. W.K.
PO,
Direction: testis
Femoral vein
PCO,
pH
PO,
PCO,
pH
PO,
PCO.
63 36 48 55 41 47 41 51 50 46
7.27
44
57
7.34 7.37 7.37 7.30 7.27 7.35 7.32 7.32 7.27 7.35 7.27 7.28 7.26 7.31 7.20 7.31 7.37 7.30 7.38 7.42 7.28 7.42 7.30 7.36 7.38 7.31 7.32 7.35
49 87 58 47 64 65 50 48 38 67 52
59 38 45 52 46
83 76 88 48 71
80 83 71
105 80 104 72 62
50
36 58 47 53 44 53 48
68 81 83 101 92 57 73 57 78 83
73 7.28 7.31 7.26 7.27 7.27 7.23 7.16 7.27 7.30 7.21 7.25 7.31 7.28
40
35 46 35 62 47 49 54 39 50
60
105 64 66
7.24 7.30 7.33 7.35 7.31 7.29 7.34
36
50
58
60
47 61 33 48 50
4 78 72 84 41 62 51 53 57 53 35 46 39 35
57 50
55 60 47 58 43 47 68 59 52 35 52 35 59 47 55
65
54
55
54
60
36 76 45 48 77 45 45 39 41 57 73 53 55 36 46
50 50
41 53 39 56 49 42 54 38 58 50 50 44
44 46 37 54 46 46 38 48 52
TABLE 2. Summary of Values Obtained pH
Internal spermatic vein Direction: kidney Direction: testis Femoral vein
P02
PCO,
Range
Mean
Range
Mean
Range
Mean
7.23-7.45 7.16-7.35 7.26-7.42
7.32 7.27 7.33
48-105 35-84 33-87
77 55 53
35-68 43-84 37-59
47 53 47
368
DONOHUE
& BROWN
FERTILITY
& STERILITY
the renal vein had a P02 range of 48-105 mm. Hg, with a mean of 77 (Table 2). The internal spermatic vein specimens taken from the direction of the testis showed measurements of P02 from 35 to 84 mm. Hg, with a mean of 55 (Table 2). The femoral vein values for P02 were from 33 to 87 mm. Hg, with a mean of 53 (Table 2). Specimens of blood secured in the same manner from the patient without clinical varicocele at the time of the repair of his hernia revealed the following: In the sample from the internal spermatic vein in the direction of the kidney, the values were: pH, 7.38; P0 2 , 68 mm. Hg; and PC0 2 , 34 mm. Hg; in the sample from the internal spermatic vein in the direction of the testis, they were: pH, 7.31; P02 , 49 mm. Hg; and PC0 2 , 34 mm. Hg. The femoral vein values were: pH, 7.38; P02 , 42 mm. Hg; and PC0 2 , 55 mm. Hg. DISCUSSION
Under normal physiologic conditions the kidneys receive approximately 25% of the cardiac output. As a result, the oxygen requirements of the kidneys are greatly exceeded by the amounts available and therefore there is a lower oxygen extraction ratio per unit volume of arterial blood, resulting in higher tensions of oxygen in the venous system of the kidney. The renal vein has the highest venous oxygen tension-P0 2 -in the systemic circulation. This is exceeded only by the pulmonary veins which are unique in that they return arterial blood to the heart. The postulation that varicocele impairs fertility by resulting in venous stasis and decreased tissue oxygenation is being challenged. It has heen suggested on the basis of this continuing study that the testis is being bathed in venous blood from the renal vein, a vein whose oxygen tension exceeds that of any other systemic vein and probably approaches arterial tensions. The varicocele may not be decreasing the oxygen tension in the venous plexus of the testis, but may in effect be increasing it. Whether increasing oxygen tension can be in itself deleterious has not been studied at this time. Ahlberg et al. have reported that 50% of all men have retrograde flow. Most of these men do not have varicocele. We believe that the elevated P0 2 in the internal spermatic vein in the 1 control patient studied to date is attributable to retrograde flow. This is probably the only way to account for the discrepancy in the oxygen tensions obtained from the same vein.
VoL. 20, No.2, 1969
BLOOD GAsEs AND PH IN VARICOCELE
369
SUMMARY
The blood pH, P02 , and PC02 were studied in 26 subfertile men with varicocele at the time of varicocelectomy. No significant differences were noted in the pH and PC02 values between the blood in the direction of the kidney and that in the direction of the testis. The internal spermatic vein blood withdrawn from the direction of the renal vein has oxygen tension increased over that of the blood withdrawn from the direction of the testis as well as from the femoral vein blood of these patients. This would tend to minimize the role of hypoxia as a mechanism by which varicocele could impair .spermatogenesis. New York University Medical Center 550 First .4.ve. New York, N.Y. 10016
REFERENCES 1. AHLBERG, N. E., BARTLEY, 0., CHIDEKEL, N., and FRITJOFSON, A. Phlebography in varicocele scroti. Acta Radiol 4:517, 1966. 2. BROWN, J., HOTcHKiss, R., and DUBIN, L. The varicocele as related to fertility. Fertil Steril18:46, 1967. 3. CHARNY, C. W. Effect of varicocele on fertility. Fertil Steril16:135, 1966. 4. DAVIDSON, H. A. Testicular temperature and varicocele. Practitioner 173:703, 1954. 5. MAcLEOD, J. Seminal cytology in the presence of varicocele. Fertil Steril 16:735, 1966. 6. PALOMO, A. Radical cure of varicocele by a new technique. I Urol 61:604, 1949. 7. TULLOCH, W. S. Consideration of sterility. Subfertility in male. (Trans. Edinburgh Obstet Soc). Edinburgh Med I 59:29, 1952.