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Microsurgical adhesiolysis: a comparative study of the CO2-laser and the microelectrode in experimental animals
Europ. J. Obstet. Gynec. reprod. Biol., 14 (1982) 55-61 Elsevier Biomedical Press
55
Microsurgical adhesiolysis: a comparative study of the CO,-laser and the microelectrode in experimental animals * P. Scheidel, G. Wallwiener Department
and H. Hepp
of Obstetrics and Qmecology, and Institute for Clinical-Experimental Saarland, Saarland, F. R. G. Accepted
for publication
Surgery, University of
28 April 1982
SCHEIDEL, P., WALLWIENER, G. and HEPP, H. (1982): Microsurgical adhesiolysis: a comparative study of the CO,-laser and the microelectrode in experimental animals. Europ. J. Obstet. Gynec. reprod. Biol., 14/l, 55-61. After traumatizing the serosa in 60 white rats, the induced adhesions were dissolved 14 days later using a CO,-laser or a microelectrode under microscopic conditions. A third laparotomy was performed 14 days thereafter to evaluate the postoperative results. Microsurgical adhesiolysis was satisfactory in 22 of 42 rats with severe adhesions. When both methods were compared, the CO,-laser results (14 out of 21) were superior to those of the microelectrode (8 out of 21). CO,-laser;
microsurgery;
adhesiolysis
Introduction Adhesions in the genital region and neighboring organs are found in a high percentage of sterile women. They are considered the primary cause of sterility in approximately 10% of all cases (Gordij, 1975). Schlosser et al. (1979) reported that in 83 cases of microsurgical reconstruction of the oviduct, 49 were combined with an adhesiolysis. In 14 of those cases, adhesiolysis proved to be the only microsurgical procedure performed. Altogether, 63 of 83 (75.9%) patients required the removal of adhesions. The renewed postoperative appearance of adhesions is considered responsible for the failure of more than 40% of all procedures (Gordij, 1975). A multitude of attempts were made to prevent the postoperative development of adhesions. Despite the abundance of scientific research, it is still not possible to explain the exact pathologic-genetic mechanism of adhesion formation. Local ischemia undoubtedly plays a significant role in the development of adhesions. Ischemia generally appears after a trauma of the serosa. Specifically, there seems to be a subsequent decrease in fibrolytic activity (plasminogen activator activity, PAA) (Benzer et al., 1963). It is quite possible that a relationship exists between the reduction of fibrolytic activity and the development of adhesions (Buckman et al., 1976). Animal experiments have shown that the trauma defect was * Supported
by a grant
from the German
0028-2243/82/0000-0000/$02.75
Volkswagen
Foundation.
0 1982 Elsevier Biomedical
Press
56
closed by subperitoneal fibroplasts after the initial cleaning phase of phagocytizing cells was completed. It remains to be seen whether this new mesothelium is a direct result of fibroblast activity, or whether it is the result of monocyte and macrophage activity from the exudate of the surrounding peritoneum (Raftery, 1973). The development of microsurgery and its application in reconstructive tubal surgery strives to reduce the operative trauma by providing exact hemostasis and a minimum of operative preparation. The number of postoperative adhesions have been substantially reduced through preparation under the operative microscope with such special instruments as Swolin’s (1966) microelectrode. Nevertheless, it is inevitable that adhesions will reappear despite scrupulous preparation and a minimum of trauma. The combination of microsurgical procedures with intraoperative cortisone therapy in reconstructive tubal surgery was an attempt to improve on hitherto disappointing .results. Toaff (1976) initiated the use of the CO,-laser in reconstructive tubal surgery using it primarily for adhesiolysis. He noted an obvious improvement over conventional methods after eight operations. A direct comparison to microsurgical techniques could not be conducted. We have therefore attempted to compare the advantages of the CO,-laser to the microelectrode in experimental animals using standardized operative procedures. Materials and methods The initial traumatization of the serosa was performed on 60 white, female rats of with chloral hydrate (3.6% inapproximately 300 g each. After anesthesia traperitoneal), the animals were laparotomized with a midline incision along the abdomen. After sufficient exposure of the uterus, a hard Perlon brush was stroked 10 times on the anterior and 10 times on the posterior sides of the uterus. This procedure served to induce adhesions. Thereafter, the uterus was severed along the middle portion. The distal fragment was attached to the lateral pelvic wall with an 8/O nylon suture. The severing of the uterus was conducted in order to combine the adhesiolysis with a reconstructive procedure (end-to-end anastomosis of the uterus horns) during the second laparotomy 14 days later. This second laparotomy also served as an opportunity to classify the degree of adhesion in the individual animals (Table I). Grades 0 and + were not considered significant adhesions, whereas grades + + and + + + were seen as significant adhesions. Two experimental groups were created by randomly selecting a rat for adhesiolysis by alternating the CO,-laser method with the microelectrode method. Both procedures were conducted under an TABLE I Classification 0 + ++
=
+++
=
= =
of adhesions no adhesions several isolated adhesions between the visceral peritoneum wide, band-like adhesions between the visceral portions of the peritoneum parietal peritoneum (only genital organs included) wide, band-like adhesions beyond the genital region, including intestines bladder
and/or
the
and/or
the
51
operative microscope. During this second laparotomy, the sealed ends of the uterus horns were opened and reanastomized under the operative microscope with 9/O nylon suture material. The CO,-laser utilized in the adhesiolysis was from the Coherent Radiation Co. It was attached to a Zeiss OPMI 1 operative microscope and controlled by a micromanipulator through a mirror-reflex system. The microelectrodes used in this study were from the Gebrtider Martin Co. along with the high frequency device which powers it. No antibiotics, corticosteroids, or other drugs were administered after relaparotomy. A third laparotomy was conducted 14 days later to inspect the operative results, and to repeat the classification of the adhesions according to the above-mentioned categories. Results Severe to very severe adhesions (+ + and + + t) were induced in 42 of 60 animals by the method described previously. The remaining 18 animals also showed obvious evidence of adhesions. Not a single one of the treated animals was completely free of adhesions. The adhesion status was clearly improved in both experimental groups after microsurgical adhesiolysis. Altogether, it was possible to obtain a marked reduction of adhesions in 32 animals. Considering that a pharmaceutical prophylaxis was dispensed with, the results of microsurgical adhesiolysis may be seen as satisfactory (Fig. 1). When examining the difference between the two experimental groups, the laser-adhesiolysis group showed 23 out of 30 animals (76.7%j without adhesions, whereas the microelectrode group showed 17 out of 30 animals (56.7%) in which only a minimal degree of adhesions was found (Figs. 2 and 3). These figures only consider the overall results and not the individual status of the animals prior to the experiment. The laser-treated group also showed a distinct trend towards better results when a reduction in the degree of adhesions was considered (for example: from a preoperative severe degree of adhesions (+ +) to a postoperative adhesion-free status (0) is a reduction of 2 grades, Fig. 4). A reduction of 3 grades was found in 7 (23.3%) of the laser-treated animals. A reduction of 1 grade was found in 10 (33.3%) animals of the laser-treated group. The postoperative result was not different from the initial adhesion status in only 4 (13.3%) of the laser-treated animals. Only 2 (6.6%) animals in this group showed more severe adhesions postoperatively than they had preoperatively. A reduction of 3 grades was achieved in only two cases (6.6%) for the animals treated with the microelectrode method. A reduction of 2 grades was found in 6 (20%) animals and a reduction of 1 grade was found in 7 (23.3%) animals. The number of rats that demonstrated no significant change from their preoperative status was as high as 13 (43.3%) in the microelectrode-treated group. Just as in the laser-treated group, only 2 (6.6%) animals showed a more severe postoperative adhesion status. The results were statistically evaluated through the &i-squared test and the U-test according to Mann-Whitney (P = 0.05). A significant difference could be obtained between the two groups.
58
A n ,.
30 .’
20--
16,7%
lO--
16,7%
0 -0
I
Grade of _.. Aaneslon
lizzBzl preop.
Fig. 1. Total results of microsurgical
postop. adhesiolysis
- microelectrode
and CO,-laser
(n =60).
Discussion The principle problem of any study,dealing with the formation or prevention of adhesions lies in the unavoidable subjective classification of the degree of adhesion. An additional difficulty is encountered when several subgroups are judged. The classification in this study was always made by the same researcher who had no previous knowledge of the operative procedure (laser or microelectrode) performed. Nethertheless, the problem of subjectivity in this study remains. Although a significant difference could be obtained between the two groups, this may not be drawn upon in attempting to prove the superiority of the CO,-laser due to the subjectivity
59
76,6%
20.-
10 ..
133%
lO,O%
0 '.
L
L
++
I
la-
Grade of Adhesion
lzzzza postop.
preop.
Fig. 2. Results of microsurgical
0
adhesiolysis
- CO,-laser
(n = 30).
of the classification. The absence of cord-like, secondary adhesions after the CO,-laser adhesiolysis of peritoneal adhesions was particularly conspicuous. These cord-like secondary adhesions were often found in the microelectrode group. The CO,-laser appears to require more familiarization than any other operative instrument, not only in its manipulation, but also in the correct determination of wattage (0 to 30 W) and the duration of application (pulsating or continuous). In a preparatory series of 10 animals which were not included in this study, three serious injuries were inflicted by the use of the laser. In one case, the vena iliaca was ruptured during adhesiolysis. Two further cases involved injuries to the ureter and the intestines. All three cases undoubtedly involved errors in the manipulation of the CO,-laser. Consequently, our operative results clearly improved with increased experience in laser manipulation. According to this study, the CO,-laser demonstrates its superiority over the microelectrode adhesiolysis, particularly with very severe adhesions (see reductions
60
4 n .
40.0%
-
10 -30,0%
-
23,3%
5 --
0 --
-
-
0
I
tzzzm postop.
preop.
Fig. 3. Results of microsurgical
tirade 01 Adhesion
adhesiolysis
- microelectrode
(electric
needle) (n = 30).
of 3 grades in Fig. 4). A conclusive explanation for this phenomenon cannot be given because the effect of the CO,-laser on different tissues has not been sufficiently investigated. The assumption can be made that improved hemostasis on the one hand, and the minimal depth of penetration (when using an appropriate energy setting) on the other, will result in laser superiority over the microelectrode. In comparison, the microelectrode with its high-frequency current is difficult to steer, and clumsy when attempting to gauge the depth of penetration. The results of this experimental animal study are not sufficient to prove the eventual superiority of the CO,-laser in adhesiolysis. The disadvantages of the laser lies not only in its high initial cost, but in its hazard to neighboring organs. The procedure must therefore be conducted with the utmost caution. The ensuing time-loss will be more than compensated by the ease and rapidity of laser adhesiolysis. The laser is particularly time-saving when dealing with vessels up to 0.5 mm which would then require no additional hemostasis in the form of bipolar coagulation. This would allow the microsurgeon a clear field of operation with fewer complications. The remaining
61
393 -
23,3%
5
6,6%
0 I
-
1 3 Grades
1
2 Grades
1 Grade
] COpLaser
Fig. 4. The reduction in the degree of adhesion microelectrode to the CO,-laser (n = 60).
No Change
WA
after
Worse
Degree 01 Reductm
Mmoelectrode
microsurgical
adhesiolysis:
a comparison
of the
reconstructive steps may be implemented in the usual manner after completion of the laser adhesiolysis. The CO,-laser could play an increased role in gynecological macro- and microsurgery, if it were possible to solve some of the instrumental problems (reducing the focal-point diameter, simplifying the reflex-mirror-arm manipulation, and the angular projection of the laser beam). It is especially noteworthy that an independent microsurgical research team (Tadir et al., 1980) has been able to confirm the results of this study. References Benzer, H., Bliimel, G. and Piza, F. (1963): Zusammenhange zwischen fibrinolytischer Aktivitat des Blutes und aseptischen Wundheilungsstijrungen im Tierexperiment. Langenbecks Arch. klin. Chir., 302, 463. Buckman, R.F., Buckman, P.D., Hufnagel, H.V. and Gervin, AS. (1976): A physiologic basis for the adhesions-free healing of deperitonealized surfaces. J. Surg. Res., 21, 67. Gordij, M. (1975): Pelvic adhesions and sterility. Acta Europ. Fertil., 6, 279. Raftery, A.T. (1973): Regeneration of parietal and visceral peritoneum: A light microscopical study. Brit. J. Surg., 60, 293. Schlosser, H.W., Frantzen, Ch. and Beck, L. (1979): ijber den Stellenwert mikrochirurgischer Techniken bei der operativen Therapie der tubaren Sterilitat. Geburtsh. u. Frauenheilk., 39, 545. Swolin, K. (1975): Electromicrosurgery and salpingostomy: long term results. Amer. J. Obstet. Gynec., 121, 418. Tadir, Y., Margara, R., Ovadia, T. and Winston, R.M.L. Laser Micro-surgery for Lysis of Intraperitoneal Adhesions. X. World Congress on Fertility and Sterility, Madrid. Toaff, R., (1975): The carbon dioxide laser in gynecological surgery. In: Laser Surgery, p. 129. Editor: I. Kaplan. Jerusalem Academic Press, Jerusalem.
55
Microsurgical adhesiolysis: a comparative study of the CO,-laser and the microelectrode in experimental animals * P. Scheidel, G. Wallwiener Department
and H. Hepp
of Obstetrics and Qmecology, and Institute for Clinical-Experimental Saarland, Saarland, F. R. G. Accepted
for publication
Surgery, University of
28 April 1982
SCHEIDEL, P., WALLWIENER, G. and HEPP, H. (1982): Microsurgical adhesiolysis: a comparative study of the CO,-laser and the microelectrode in experimental animals. Europ. J. Obstet. Gynec. reprod. Biol., 14/l, 55-61. After traumatizing the serosa in 60 white rats, the induced adhesions were dissolved 14 days later using a CO,-laser or a microelectrode under microscopic conditions. A third laparotomy was performed 14 days thereafter to evaluate the postoperative results. Microsurgical adhesiolysis was satisfactory in 22 of 42 rats with severe adhesions. When both methods were compared, the CO,-laser results (14 out of 21) were superior to those of the microelectrode (8 out of 21). CO,-laser;
microsurgery;
adhesiolysis
Introduction Adhesions in the genital region and neighboring organs are found in a high percentage of sterile women. They are considered the primary cause of sterility in approximately 10% of all cases (Gordij, 1975). Schlosser et al. (1979) reported that in 83 cases of microsurgical reconstruction of the oviduct, 49 were combined with an adhesiolysis. In 14 of those cases, adhesiolysis proved to be the only microsurgical procedure performed. Altogether, 63 of 83 (75.9%) patients required the removal of adhesions. The renewed postoperative appearance of adhesions is considered responsible for the failure of more than 40% of all procedures (Gordij, 1975). A multitude of attempts were made to prevent the postoperative development of adhesions. Despite the abundance of scientific research, it is still not possible to explain the exact pathologic-genetic mechanism of adhesion formation. Local ischemia undoubtedly plays a significant role in the development of adhesions. Ischemia generally appears after a trauma of the serosa. Specifically, there seems to be a subsequent decrease in fibrolytic activity (plasminogen activator activity, PAA) (Benzer et al., 1963). It is quite possible that a relationship exists between the reduction of fibrolytic activity and the development of adhesions (Buckman et al., 1976). Animal experiments have shown that the trauma defect was * Supported
by a grant
from the German
0028-2243/82/0000-0000/$02.75
Volkswagen
Foundation.
0 1982 Elsevier Biomedical
Press
56
closed by subperitoneal fibroplasts after the initial cleaning phase of phagocytizing cells was completed. It remains to be seen whether this new mesothelium is a direct result of fibroblast activity, or whether it is the result of monocyte and macrophage activity from the exudate of the surrounding peritoneum (Raftery, 1973). The development of microsurgery and its application in reconstructive tubal surgery strives to reduce the operative trauma by providing exact hemostasis and a minimum of operative preparation. The number of postoperative adhesions have been substantially reduced through preparation under the operative microscope with such special instruments as Swolin’s (1966) microelectrode. Nevertheless, it is inevitable that adhesions will reappear despite scrupulous preparation and a minimum of trauma. The combination of microsurgical procedures with intraoperative cortisone therapy in reconstructive tubal surgery was an attempt to improve on hitherto disappointing .results. Toaff (1976) initiated the use of the CO,-laser in reconstructive tubal surgery using it primarily for adhesiolysis. He noted an obvious improvement over conventional methods after eight operations. A direct comparison to microsurgical techniques could not be conducted. We have therefore attempted to compare the advantages of the CO,-laser to the microelectrode in experimental animals using standardized operative procedures. Materials and methods The initial traumatization of the serosa was performed on 60 white, female rats of with chloral hydrate (3.6% inapproximately 300 g each. After anesthesia traperitoneal), the animals were laparotomized with a midline incision along the abdomen. After sufficient exposure of the uterus, a hard Perlon brush was stroked 10 times on the anterior and 10 times on the posterior sides of the uterus. This procedure served to induce adhesions. Thereafter, the uterus was severed along the middle portion. The distal fragment was attached to the lateral pelvic wall with an 8/O nylon suture. The severing of the uterus was conducted in order to combine the adhesiolysis with a reconstructive procedure (end-to-end anastomosis of the uterus horns) during the second laparotomy 14 days later. This second laparotomy also served as an opportunity to classify the degree of adhesion in the individual animals (Table I). Grades 0 and + were not considered significant adhesions, whereas grades + + and + + + were seen as significant adhesions. Two experimental groups were created by randomly selecting a rat for adhesiolysis by alternating the CO,-laser method with the microelectrode method. Both procedures were conducted under an TABLE I Classification 0 + ++
=
+++
=
= =
of adhesions no adhesions several isolated adhesions between the visceral peritoneum wide, band-like adhesions between the visceral portions of the peritoneum parietal peritoneum (only genital organs included) wide, band-like adhesions beyond the genital region, including intestines bladder
and/or
the
and/or
the
51
operative microscope. During this second laparotomy, the sealed ends of the uterus horns were opened and reanastomized under the operative microscope with 9/O nylon suture material. The CO,-laser utilized in the adhesiolysis was from the Coherent Radiation Co. It was attached to a Zeiss OPMI 1 operative microscope and controlled by a micromanipulator through a mirror-reflex system. The microelectrodes used in this study were from the Gebrtider Martin Co. along with the high frequency device which powers it. No antibiotics, corticosteroids, or other drugs were administered after relaparotomy. A third laparotomy was conducted 14 days later to inspect the operative results, and to repeat the classification of the adhesions according to the above-mentioned categories. Results Severe to very severe adhesions (+ + and + + t) were induced in 42 of 60 animals by the method described previously. The remaining 18 animals also showed obvious evidence of adhesions. Not a single one of the treated animals was completely free of adhesions. The adhesion status was clearly improved in both experimental groups after microsurgical adhesiolysis. Altogether, it was possible to obtain a marked reduction of adhesions in 32 animals. Considering that a pharmaceutical prophylaxis was dispensed with, the results of microsurgical adhesiolysis may be seen as satisfactory (Fig. 1). When examining the difference between the two experimental groups, the laser-adhesiolysis group showed 23 out of 30 animals (76.7%j without adhesions, whereas the microelectrode group showed 17 out of 30 animals (56.7%) in which only a minimal degree of adhesions was found (Figs. 2 and 3). These figures only consider the overall results and not the individual status of the animals prior to the experiment. The laser-treated group also showed a distinct trend towards better results when a reduction in the degree of adhesions was considered (for example: from a preoperative severe degree of adhesions (+ +) to a postoperative adhesion-free status (0) is a reduction of 2 grades, Fig. 4). A reduction of 3 grades was found in 7 (23.3%) of the laser-treated animals. A reduction of 1 grade was found in 10 (33.3%) animals of the laser-treated group. The postoperative result was not different from the initial adhesion status in only 4 (13.3%) of the laser-treated animals. Only 2 (6.6%) animals in this group showed more severe adhesions postoperatively than they had preoperatively. A reduction of 3 grades was achieved in only two cases (6.6%) for the animals treated with the microelectrode method. A reduction of 2 grades was found in 6 (20%) animals and a reduction of 1 grade was found in 7 (23.3%) animals. The number of rats that demonstrated no significant change from their preoperative status was as high as 13 (43.3%) in the microelectrode-treated group. Just as in the laser-treated group, only 2 (6.6%) animals showed a more severe postoperative adhesion status. The results were statistically evaluated through the &i-squared test and the U-test according to Mann-Whitney (P = 0.05). A significant difference could be obtained between the two groups.
58
A n ,.
30 .’
20--
16,7%
lO--
16,7%
0 -0
I
Grade of _.. Aaneslon
lizzBzl preop.
Fig. 1. Total results of microsurgical
postop. adhesiolysis
- microelectrode
and CO,-laser
(n =60).
Discussion The principle problem of any study,dealing with the formation or prevention of adhesions lies in the unavoidable subjective classification of the degree of adhesion. An additional difficulty is encountered when several subgroups are judged. The classification in this study was always made by the same researcher who had no previous knowledge of the operative procedure (laser or microelectrode) performed. Nethertheless, the problem of subjectivity in this study remains. Although a significant difference could be obtained between the two groups, this may not be drawn upon in attempting to prove the superiority of the CO,-laser due to the subjectivity
59
76,6%
20.-
10 ..
133%
lO,O%
0 '.
L
L
++
I
la-
Grade of Adhesion
lzzzza postop.
preop.
Fig. 2. Results of microsurgical
0
adhesiolysis
- CO,-laser
(n = 30).
of the classification. The absence of cord-like, secondary adhesions after the CO,-laser adhesiolysis of peritoneal adhesions was particularly conspicuous. These cord-like secondary adhesions were often found in the microelectrode group. The CO,-laser appears to require more familiarization than any other operative instrument, not only in its manipulation, but also in the correct determination of wattage (0 to 30 W) and the duration of application (pulsating or continuous). In a preparatory series of 10 animals which were not included in this study, three serious injuries were inflicted by the use of the laser. In one case, the vena iliaca was ruptured during adhesiolysis. Two further cases involved injuries to the ureter and the intestines. All three cases undoubtedly involved errors in the manipulation of the CO,-laser. Consequently, our operative results clearly improved with increased experience in laser manipulation. According to this study, the CO,-laser demonstrates its superiority over the microelectrode adhesiolysis, particularly with very severe adhesions (see reductions
60
4 n .
40.0%
-
10 -30,0%
-
23,3%
5 --
0 --
-
-
0
I
tzzzm postop.
preop.
Fig. 3. Results of microsurgical
tirade 01 Adhesion
adhesiolysis
- microelectrode
(electric
needle) (n = 30).
of 3 grades in Fig. 4). A conclusive explanation for this phenomenon cannot be given because the effect of the CO,-laser on different tissues has not been sufficiently investigated. The assumption can be made that improved hemostasis on the one hand, and the minimal depth of penetration (when using an appropriate energy setting) on the other, will result in laser superiority over the microelectrode. In comparison, the microelectrode with its high-frequency current is difficult to steer, and clumsy when attempting to gauge the depth of penetration. The results of this experimental animal study are not sufficient to prove the eventual superiority of the CO,-laser in adhesiolysis. The disadvantages of the laser lies not only in its high initial cost, but in its hazard to neighboring organs. The procedure must therefore be conducted with the utmost caution. The ensuing time-loss will be more than compensated by the ease and rapidity of laser adhesiolysis. The laser is particularly time-saving when dealing with vessels up to 0.5 mm which would then require no additional hemostasis in the form of bipolar coagulation. This would allow the microsurgeon a clear field of operation with fewer complications. The remaining
61
393 -
23,3%
5
6,6%
0 I
-
1 3 Grades
1
2 Grades
1 Grade
] COpLaser
Fig. 4. The reduction in the degree of adhesion microelectrode to the CO,-laser (n = 60).
No Change
WA
after
Worse
Degree 01 Reductm
Mmoelectrode
microsurgical
adhesiolysis:
a comparison
of the
reconstructive steps may be implemented in the usual manner after completion of the laser adhesiolysis. The CO,-laser could play an increased role in gynecological macro- and microsurgery, if it were possible to solve some of the instrumental problems (reducing the focal-point diameter, simplifying the reflex-mirror-arm manipulation, and the angular projection of the laser beam). It is especially noteworthy that an independent microsurgical research team (Tadir et al., 1980) has been able to confirm the results of this study. References Benzer, H., Bliimel, G. and Piza, F. (1963): Zusammenhange zwischen fibrinolytischer Aktivitat des Blutes und aseptischen Wundheilungsstijrungen im Tierexperiment. Langenbecks Arch. klin. Chir., 302, 463. Buckman, R.F., Buckman, P.D., Hufnagel, H.V. and Gervin, AS. (1976): A physiologic basis for the adhesions-free healing of deperitonealized surfaces. J. Surg. Res., 21, 67. Gordij, M. (1975): Pelvic adhesions and sterility. Acta Europ. Fertil., 6, 279. Raftery, A.T. (1973): Regeneration of parietal and visceral peritoneum: A light microscopical study. Brit. J. Surg., 60, 293. Schlosser, H.W., Frantzen, Ch. and Beck, L. (1979): ijber den Stellenwert mikrochirurgischer Techniken bei der operativen Therapie der tubaren Sterilitat. Geburtsh. u. Frauenheilk., 39, 545. Swolin, K. (1975): Electromicrosurgery and salpingostomy: long term results. Amer. J. Obstet. Gynec., 121, 418. Tadir, Y., Margara, R., Ovadia, T. and Winston, R.M.L. Laser Micro-surgery for Lysis of Intraperitoneal Adhesions. X. World Congress on Fertility and Sterility, Madrid. Toaff, R., (1975): The carbon dioxide laser in gynecological surgery. In: Laser Surgery, p. 129. Editor: I. Kaplan. Jerusalem Academic Press, Jerusalem.