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Preoperative leuprolide acetate combined with Interceed* optimally reduces uterine adhesions and fibrosis in a rabbit model
FERTILITY AND STERILITY威 VOL. 81, NO. 1, JANUARY 2004 Copyright ©2004 American Society for Reproductive Medicine Published by Elsevier Inc. Printed on acid-free paper in U.S.A.
Preoperative leuprolide acetate combined with Interceed* optimally reduces uterine adhesions and fibrosis in a rabbit model Paul B. Marshburn, M.D.,a James M. Meek, M.D.,a Helen E. Gruber, Ph.D.,b Brian E. Gordon, D.V.M.,c James H. Norton, Ph.D.,d and Bradley S. Hurst, M.D.a Carolinas Medical Center, Charlotte, North Carolina
Received February 25, 2003; revised and accepted July 30, 2003. *Interceed, Johnson & Johnson Medical, Inc., New Brunswick, New Jersey. Supported by a grant from the Carolinas HealthCare System Foundation, Charlotte, North Carolina. Reprint requests: Paul B. Marshburn, M.D., Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, North Carolina 28232 (FAX: 704-355-1941; E-mail: paul.marshburn@ carolinashealthcare.org). a Department of Obstetrics and Gynecology. b Department of Orthopedic Research. c Department of Comparative Medicine. d Department of Biostatistics. 0015-0282/04/$30.00 doi:10.1016/j.fertnstert.2003. 07.009
194
Objective: To determine the optimal approach to prevent adhesions comparing leuprolide acetate (GnRH-a), Interceed (oxidized regenerated cellulose; Johnson & Johnson Medical, Inc., New Brunswick, NJ), and a combination of leuprolide with Interceed in a rabbit uterine horn adhesion model. Design: Prospective, randomized, blinded study. Setting: Certified animal care facility. Animal(s): Twenty-eight sexually mature, female New Zealand White rabbits. Intervention(s): Animals were prospectively randomized (by number generator) to receive GnRH-a or saline. After 6 weeks, standard surgical manipulations were performed at three sites in each uterine horn by [1] suture, [2] unipolar cautery, and [3] superficial abrasion. Interceed was applied over one randomly assigned uterine horn only. Six weeks after surgery, uterine adhesions were assessed visually, and tissue fibrosis was assessed by histology. Main Outcome Measure(s): Presence or absence of adhesions and microscopic tissue fibrosis. Result(s): Gonadotropin–releasing hormone agonist significantly decreased adhesions, whereas Interceed alone did not reduce adhesions. However, GnRH agonist plus Interceed was the most effective measure to reduce tissue fibrosis. Conclusion(s): Preoperative GnRH-a is more effective than Interceed in preventing surgical adhesions in the rabbit uterine horn. However, preoperative GnRH-a plus Interceed may provide optimal results in this animal model, because microscopic tissue fibrosis is minimized with this combination. (Fertil Steril威 2004;81:194-7. ©2004 by American Society for Reproductive Medicine.) Key Words: Adhesion, fibrosis, uterus, leuprolide acetate, GnRH-a, hypo-estrogenism, oxidized regenerated cellulose, Interceed, rabbit
Postoperative adhesions and tissue fibrosis compromise the outcome of reproductive surgery. Both oxidized regenerated cellulose (Interceed; Johnson & Johnson Medical, Inc., New Brunswick, NJ) and the gonadotropin–releasing hormone agonist (GnRH-a) leuprolide acetate have shown a degree of efficacy in adhesion prevention after reproductive surgery (1, 2). The purpose of this study was to examine whether preoperative GnRH-a, with or without Interceed, would reduce postoperative adhesions and tissue fibrosis after controlled surgical manipulations of the uterine horn of rabbits.
MATERIALS AND METHODS Twenty-eight sexually mature, female New Zealand White rabbits (average weight, 3.5 to
4.0 kg) were housed and cared for by standard protocols of the Carolinas Medical Center vivarium. Experiments were performed under the supervision of an in-house veterinarian, after review and approval by the institutional animal care and use committee. A summary of the experimental protocol is shown in Figure 1. The number of rabbits in each group was determined by the expected incidence of pelvic adhesions that was found after surgical trauma in a previous study (3). Animals were housed for 2 weeks before treatment. Twelve animals were prospectively randomized using random number tables to the GnRH-a (depot leuprolide acetate; Lupron, TAP Pharmaceuticals, Inc., Deerfield, IL) group, 12 to the placebo control group, and 4 to the sham-
FIGURE 1 Experimental study groups used to evaluate the effect of GnRH-a and Interceed on adhesions and tissue fibrosis in the rabbit uterine horn. In this figure, Interceed is placed on the left uterine horn. A ⫽ abrasion; B ⫽ cautery; C ⫽ suture.
Marshburn. GnRH-agonist and Interceed for adhesions. Fertil Steril 2004.
operated group. The GnRH-a–treated animals received depot leuprolide acetate (3.75 mg i.m.) every 3 weeks for a 6-week treatment. This regimen induces significant and marked hypoestrogenism in rabbits (4). The control group received an identical volume and frequency of i.m. saline. Of the four animals serving as the nonsurgical controls, two received GnRH-a as above, and two received saline. Standardized surgical uterine horn manipulations were performed 6 weeks after the initiation of GnRH-a or placebo treatment. Surgeons were blinded to the treatment groups. Rabbits were anesthetized with acepromazine (1 mg/kg i.m.) and ketamine (20 mg/kg i.m.), then shaved and prepped with Betadine solution under sterile surgical conditions. A midline vertical abdominal incision was performed, and the uterine horns were identified and gently brought through the incision. No adhesions were noted in any of the animals. In the surgical study groups, three separate standardized surgical manipulations were made on both horns of each animal: suture, cautery, and abrasion. The suture was a 3– 0 polyglycolic acid suture (Vicryl) that was placed in the distal uterine horn and tied with a square knot. The second manipulation of unipolar cautery was used in the middle aspect of each horn, with 30 W of blended current applied to 1 cm in length and 50% of the uterine horn serosa width. The abrasion was created by vigorously rubbing a scalpel upon the proximal horn serosa until modest oozing of FERTILITY & STERILITY威
blood occurred, 1 cm lateral to the uterine bifurcation and 1.5 cm medial to the cautery injury. Interceed was randomly assigned to one horn in each animal and was placed to cover all three manipulation sites after bleeding had stopped. The other manipulated uterine horn served as the non-Interceed control. It is of note that no active bleeding occurred to darken the Interceed membrane with blood. The uterine horns were gently returned to their pelvic location without disrupting Interceed placement. The four sham surgical control animals had laparotomy and treatment similar to the GnRH-a and control groups, except that no surgical manipulations were performed on the uterine horns. Interceed placement on one uterine horn was randomly assigned for each of the sham-operated animals. In all animals, the fascia was closed using 0 – 0 polydioxanone suture, and the skin was closed with metal skin staples. All animals were killed 6 weeks after initial laparotomy, and necropsy was performed through a midline vertical incision. Three observers blinded to treatment groups independently recorded the presence or absence of adhesions for each surgical manipulation site. The uterine horns, ovaries, and adhesions to adjacent tissues were carefully excised en bloc and fixed in 10% neutral buffered formalin solution. The fixed tissue was 195
TABLE 1 Adhesions and fibrosis after surgical manipulations of the rabbit uterine horn. Presence of adhesionsa Manipulation Suture Cautery Abrasion Suture ⫹ Interceed Cautery ⫹ Interceed Abrasion ⫹ Interceed
Fibrosis scoreb
Control
GnRH-a
Control
GnRH-a
3/12 4/12 5/12 3/12 4/12 4/12
1/12 2/12 2/12 1/12 2/12 2/12
2.6 ⫾ 0.3 0.4 ⫾ 0.2 0.7 ⫾ 0.4 2.0 ⫾ 0.4 1.4 ⫾ 0.4 1.2 ⫾ 0.4c
2.2 ⫾ 0.4 0.1 ⫾ 0.1 1.7 ⫾ 0.3 1.6 ⫾ 0.4 0.8 ⫾ 0.4 0.0c
a
GnRH-a reduced postoperative adhesions with (P⫽.03) or without (P⫽.04) Interceed. Using generalized estimating equations logistic regression, GnRH-a significantly decreased adhesions (P⫽.002). There were no statistical differences among the three manipulation sites or between the sites with or without Interceed. b Fibrosis score ⫾ standard deviation (5). No comparison revealed a statistical difference except the combination of GnRH-a with Interceed. c P⫽.001. Marshburn. GnRH-agonist and Interceed for adhesions. Fertil Steril 2004.
embedded in paraffin, and representative sections of the manipulated areas were cut into 5-m sections. Microscopic hematoxylin and eosin–stained sections were evaluated microscopically by two blinded investigators who were familiar with rabbit histology. The severity of tissue fibrosis and inflammation was scored according to established methods as follows: 0 —normal; 1—mild changes, edema; 2—plasma cells, monocytes, edema, congestion; 3—minor fibrosis, minor organized connective tissue dilatation; and 4 —major architectural distortion and extensive damage (5). Statistical testing was performed on the SAS System for Windows, version 8.2. Descriptive statistics, including counts and percentages, were calculated. Multivariate analysis was used to evaluate the incidence of adhesions at multiple sites. Because several treatment sites were evaluated on each rabbit, the data are not independent, and therefore the generalized estimating equations methodology was used. The generalized estimating equations methodology allows the analysis of correlation data from logistic regression when the outcome is dichotomous (adhesion or no adhesion), where six measurements have been taken on each animal (6). The Wilcoxon rank sum test was employed to evaluate the histology measurements that were on the ordinal scale. A P value of ⬍.05 was considered statistically significant.
RESULTS Overall, GnRH-a significantly decreased adhesions (P⫽.002) compared with the case of Interceed and controls (Table 1), according to generalized estimating equations logistic regression. Gonadotropin–releasing hormone agonist pretreatment resulted in a significant decrease in postoperative adhesions compared with the saline control group, both with (P⫽.03) and without (P⫽.04) Interceed. On the other hand, Interceed did not prevent or increase adhesions. No adhesions were found in any of the sham-operated animals (i.e., no uterine lesioning), indicating no independent adhe196
Marshburn et al.
sion formation from the laparotomy alone. No surgical manipulation sites had adhesions to any other uterine site, but rather only to other abdominal structures. In all, 168 sites were evaluated by the three surgeons blinded to treatment, and there was complete agreement 97% of the time. The remaining 3% of the observations were scored according to agreement between two of the three blinded observers. In contrast to the adhesion study, GnRH-a pretreatment combined with Interceed significantly reduced fibrosis and inflammation compared with Interceed or GnRH-a alone (P⬍.001).
DISCUSSION Data from this study support the hypothesis that GnRH-a– induced pituitary suppression reduces adhesions, fibrosis, and inflammation that may occur after pelvic surgery. However, the combination of Interceed and GnRH-a was needed to achieve optimal reduction in adhesions and tissue fibrosis in this study. Because surgically lesioned sites had no adhesions to other lesioned sites, the effects of GnRH-a and Interceed on healing could be evaluated independently. Differences in results from animal to animal variation were minimized in this model because each rabbit served as its own internal control. The mechanism for the GnRH-a–induced reduction of adhesions is not clear, but recent studies have provided evidence that hypoestrogenism can modify the inflammatory response or alter tissue remodeling (7). Interceed alone did not reduce adhesions in our animal model, possibly because of the mild degree of trauma induced by the three uterine manipulations used. Although absolute hemostasis was established before placing the Interceed, it is possible that a small amount of blood at the abrasion site reduced the effectiveness of Interceed (8). Perhaps the inclusion of more rabbits per test group or the use of more traumatic lesioning would have resulted in the detection of a preventive effect of Interceed on postoperative adhesions.
GnRH-agonist and Interceed for adhesions
Vol. 81, No. 1, January 2004
Under the conditions of this study, however, GnRH-a reduced the presence of postoperative adhesions, whereas Interceed did not. Even when macroscopic adhesions do not form, tissue fibrosis may result in organ dysfunction. Grossly normal fallopian tubes from patients with ectopic pregnancies are found to have microscopic evidence of inflammatory change (9). We believe that interventions that reduce tissue fibrosis may enhance the effectiveness of reproductive surgery. In conclusion, GnRH-a pretreatment decreases adhesions, whereas no benefit is seen with Interceed alone. However, adhesions and fibrosis are both reduced when GnRH-a is combined with Interceed. Further study is needed to determine whether GnRH-a pretreatment, alone or in combination with adhesion barriers, enhances reproductive surgery in women.
Acknowledgments: The expert advice and work of Terry Loeb (Carolinas Medical Center) on study design are gratefully acknowledged. The administrative and manuscript preparation was expertly performed by Lillian Lawrence (Carolinas Medical Center).
FERTILITY & STERILITY威
References 1. Mais V, Ajossa S, Piras B, Guerriero S, Marongiu D, Melis GB. Prevention of de novo adhesion formation after laparoscopic myomectomy: a randomized trial to evaluate the effectiveness of an oxidized regenerated cellulose absorbable barrier. Hum Reprod 1995; 10:3133–5. 2. Grow DR, Coddington CC, Hsiu JG, Mikich Y, Hodgen GD. Role of hypoestrogenism or sex steroid antagonism in adhesion formation after myometrial surgery in primates. Fertil Steril 1996;66:140 –6. 3. Boyers SP, Diamond MP, DeCherney AH. Reduction of postoperative pelvic adhesions in the rabbit with Gore-Tex surgical membrane. Fertil Steril 1988;49:1066 –70. 4. Zanagnolo V, Dharmarajan AM, Hesla J, Wallach EE. Effects of gonadotropin releasing hormone analog on rabbit ovarian function. Endocrinology 1996;137:5400 –6. 5. Cross SS. Grading and scoring in histopathology. Histopathology 1998; 33:99 –106. 6. Diggle PJ, Liang KY, Zeger LL. Analysis of longitudinal data. Oxford, United Kingdom: Oxford Science Publications, 1995. 7. Sharpe-Timms KL, Zimmer RL, Jolliff WJ, Wright JA, Nothnick WB, Curry TE. Gonadotropin-releasing hormone agonist (GnRH-a) therapy alters activity of plasminogen activators, matrix metalloproteinases, and their inhibitors in rat models for adhesion formation and endometriosis: potential GnRH-a-regulated mechanisms reducing adhesion formation. Fertil Steril 1998;69:916 –23. 8. Wiseman DM, Gottlick-Iarkowski L, Kamp L. Effect of different barriers of oxidized regenerated cellulose (ORC) on cecal and sidewall adhesions in the presence and absence of bleeding. J Invest Surg 1999; 12:141–6. 9. Cumming DC, Honore LH, Scott JZ, Williams KE. Microscopic evidence of silent inflammation in grossly normal fallopian tubes with ectopic pregnancy. Int J Fertil 1988;33:324 –8.
197
Preoperative leuprolide acetate combined with Interceed* optimally reduces uterine adhesions and fibrosis in a rabbit model Paul B. Marshburn, M.D.,a James M. Meek, M.D.,a Helen E. Gruber, Ph.D.,b Brian E. Gordon, D.V.M.,c James H. Norton, Ph.D.,d and Bradley S. Hurst, M.D.a Carolinas Medical Center, Charlotte, North Carolina
Received February 25, 2003; revised and accepted July 30, 2003. *Interceed, Johnson & Johnson Medical, Inc., New Brunswick, New Jersey. Supported by a grant from the Carolinas HealthCare System Foundation, Charlotte, North Carolina. Reprint requests: Paul B. Marshburn, M.D., Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Carolinas Medical Center, 1000 Blythe Boulevard, Charlotte, North Carolina 28232 (FAX: 704-355-1941; E-mail: paul.marshburn@ carolinashealthcare.org). a Department of Obstetrics and Gynecology. b Department of Orthopedic Research. c Department of Comparative Medicine. d Department of Biostatistics. 0015-0282/04/$30.00 doi:10.1016/j.fertnstert.2003. 07.009
194
Objective: To determine the optimal approach to prevent adhesions comparing leuprolide acetate (GnRH-a), Interceed (oxidized regenerated cellulose; Johnson & Johnson Medical, Inc., New Brunswick, NJ), and a combination of leuprolide with Interceed in a rabbit uterine horn adhesion model. Design: Prospective, randomized, blinded study. Setting: Certified animal care facility. Animal(s): Twenty-eight sexually mature, female New Zealand White rabbits. Intervention(s): Animals were prospectively randomized (by number generator) to receive GnRH-a or saline. After 6 weeks, standard surgical manipulations were performed at three sites in each uterine horn by [1] suture, [2] unipolar cautery, and [3] superficial abrasion. Interceed was applied over one randomly assigned uterine horn only. Six weeks after surgery, uterine adhesions were assessed visually, and tissue fibrosis was assessed by histology. Main Outcome Measure(s): Presence or absence of adhesions and microscopic tissue fibrosis. Result(s): Gonadotropin–releasing hormone agonist significantly decreased adhesions, whereas Interceed alone did not reduce adhesions. However, GnRH agonist plus Interceed was the most effective measure to reduce tissue fibrosis. Conclusion(s): Preoperative GnRH-a is more effective than Interceed in preventing surgical adhesions in the rabbit uterine horn. However, preoperative GnRH-a plus Interceed may provide optimal results in this animal model, because microscopic tissue fibrosis is minimized with this combination. (Fertil Steril威 2004;81:194-7. ©2004 by American Society for Reproductive Medicine.) Key Words: Adhesion, fibrosis, uterus, leuprolide acetate, GnRH-a, hypo-estrogenism, oxidized regenerated cellulose, Interceed, rabbit
Postoperative adhesions and tissue fibrosis compromise the outcome of reproductive surgery. Both oxidized regenerated cellulose (Interceed; Johnson & Johnson Medical, Inc., New Brunswick, NJ) and the gonadotropin–releasing hormone agonist (GnRH-a) leuprolide acetate have shown a degree of efficacy in adhesion prevention after reproductive surgery (1, 2). The purpose of this study was to examine whether preoperative GnRH-a, with or without Interceed, would reduce postoperative adhesions and tissue fibrosis after controlled surgical manipulations of the uterine horn of rabbits.
MATERIALS AND METHODS Twenty-eight sexually mature, female New Zealand White rabbits (average weight, 3.5 to
4.0 kg) were housed and cared for by standard protocols of the Carolinas Medical Center vivarium. Experiments were performed under the supervision of an in-house veterinarian, after review and approval by the institutional animal care and use committee. A summary of the experimental protocol is shown in Figure 1. The number of rabbits in each group was determined by the expected incidence of pelvic adhesions that was found after surgical trauma in a previous study (3). Animals were housed for 2 weeks before treatment. Twelve animals were prospectively randomized using random number tables to the GnRH-a (depot leuprolide acetate; Lupron, TAP Pharmaceuticals, Inc., Deerfield, IL) group, 12 to the placebo control group, and 4 to the sham-
FIGURE 1 Experimental study groups used to evaluate the effect of GnRH-a and Interceed on adhesions and tissue fibrosis in the rabbit uterine horn. In this figure, Interceed is placed on the left uterine horn. A ⫽ abrasion; B ⫽ cautery; C ⫽ suture.
Marshburn. GnRH-agonist and Interceed for adhesions. Fertil Steril 2004.
operated group. The GnRH-a–treated animals received depot leuprolide acetate (3.75 mg i.m.) every 3 weeks for a 6-week treatment. This regimen induces significant and marked hypoestrogenism in rabbits (4). The control group received an identical volume and frequency of i.m. saline. Of the four animals serving as the nonsurgical controls, two received GnRH-a as above, and two received saline. Standardized surgical uterine horn manipulations were performed 6 weeks after the initiation of GnRH-a or placebo treatment. Surgeons were blinded to the treatment groups. Rabbits were anesthetized with acepromazine (1 mg/kg i.m.) and ketamine (20 mg/kg i.m.), then shaved and prepped with Betadine solution under sterile surgical conditions. A midline vertical abdominal incision was performed, and the uterine horns were identified and gently brought through the incision. No adhesions were noted in any of the animals. In the surgical study groups, three separate standardized surgical manipulations were made on both horns of each animal: suture, cautery, and abrasion. The suture was a 3– 0 polyglycolic acid suture (Vicryl) that was placed in the distal uterine horn and tied with a square knot. The second manipulation of unipolar cautery was used in the middle aspect of each horn, with 30 W of blended current applied to 1 cm in length and 50% of the uterine horn serosa width. The abrasion was created by vigorously rubbing a scalpel upon the proximal horn serosa until modest oozing of FERTILITY & STERILITY威
blood occurred, 1 cm lateral to the uterine bifurcation and 1.5 cm medial to the cautery injury. Interceed was randomly assigned to one horn in each animal and was placed to cover all three manipulation sites after bleeding had stopped. The other manipulated uterine horn served as the non-Interceed control. It is of note that no active bleeding occurred to darken the Interceed membrane with blood. The uterine horns were gently returned to their pelvic location without disrupting Interceed placement. The four sham surgical control animals had laparotomy and treatment similar to the GnRH-a and control groups, except that no surgical manipulations were performed on the uterine horns. Interceed placement on one uterine horn was randomly assigned for each of the sham-operated animals. In all animals, the fascia was closed using 0 – 0 polydioxanone suture, and the skin was closed with metal skin staples. All animals were killed 6 weeks after initial laparotomy, and necropsy was performed through a midline vertical incision. Three observers blinded to treatment groups independently recorded the presence or absence of adhesions for each surgical manipulation site. The uterine horns, ovaries, and adhesions to adjacent tissues were carefully excised en bloc and fixed in 10% neutral buffered formalin solution. The fixed tissue was 195
TABLE 1 Adhesions and fibrosis after surgical manipulations of the rabbit uterine horn. Presence of adhesionsa Manipulation Suture Cautery Abrasion Suture ⫹ Interceed Cautery ⫹ Interceed Abrasion ⫹ Interceed
Fibrosis scoreb
Control
GnRH-a
Control
GnRH-a
3/12 4/12 5/12 3/12 4/12 4/12
1/12 2/12 2/12 1/12 2/12 2/12
2.6 ⫾ 0.3 0.4 ⫾ 0.2 0.7 ⫾ 0.4 2.0 ⫾ 0.4 1.4 ⫾ 0.4 1.2 ⫾ 0.4c
2.2 ⫾ 0.4 0.1 ⫾ 0.1 1.7 ⫾ 0.3 1.6 ⫾ 0.4 0.8 ⫾ 0.4 0.0c
a
GnRH-a reduced postoperative adhesions with (P⫽.03) or without (P⫽.04) Interceed. Using generalized estimating equations logistic regression, GnRH-a significantly decreased adhesions (P⫽.002). There were no statistical differences among the three manipulation sites or between the sites with or without Interceed. b Fibrosis score ⫾ standard deviation (5). No comparison revealed a statistical difference except the combination of GnRH-a with Interceed. c P⫽.001. Marshburn. GnRH-agonist and Interceed for adhesions. Fertil Steril 2004.
embedded in paraffin, and representative sections of the manipulated areas were cut into 5-m sections. Microscopic hematoxylin and eosin–stained sections were evaluated microscopically by two blinded investigators who were familiar with rabbit histology. The severity of tissue fibrosis and inflammation was scored according to established methods as follows: 0 —normal; 1—mild changes, edema; 2—plasma cells, monocytes, edema, congestion; 3—minor fibrosis, minor organized connective tissue dilatation; and 4 —major architectural distortion and extensive damage (5). Statistical testing was performed on the SAS System for Windows, version 8.2. Descriptive statistics, including counts and percentages, were calculated. Multivariate analysis was used to evaluate the incidence of adhesions at multiple sites. Because several treatment sites were evaluated on each rabbit, the data are not independent, and therefore the generalized estimating equations methodology was used. The generalized estimating equations methodology allows the analysis of correlation data from logistic regression when the outcome is dichotomous (adhesion or no adhesion), where six measurements have been taken on each animal (6). The Wilcoxon rank sum test was employed to evaluate the histology measurements that were on the ordinal scale. A P value of ⬍.05 was considered statistically significant.
RESULTS Overall, GnRH-a significantly decreased adhesions (P⫽.002) compared with the case of Interceed and controls (Table 1), according to generalized estimating equations logistic regression. Gonadotropin–releasing hormone agonist pretreatment resulted in a significant decrease in postoperative adhesions compared with the saline control group, both with (P⫽.03) and without (P⫽.04) Interceed. On the other hand, Interceed did not prevent or increase adhesions. No adhesions were found in any of the sham-operated animals (i.e., no uterine lesioning), indicating no independent adhe196
Marshburn et al.
sion formation from the laparotomy alone. No surgical manipulation sites had adhesions to any other uterine site, but rather only to other abdominal structures. In all, 168 sites were evaluated by the three surgeons blinded to treatment, and there was complete agreement 97% of the time. The remaining 3% of the observations were scored according to agreement between two of the three blinded observers. In contrast to the adhesion study, GnRH-a pretreatment combined with Interceed significantly reduced fibrosis and inflammation compared with Interceed or GnRH-a alone (P⬍.001).
DISCUSSION Data from this study support the hypothesis that GnRH-a– induced pituitary suppression reduces adhesions, fibrosis, and inflammation that may occur after pelvic surgery. However, the combination of Interceed and GnRH-a was needed to achieve optimal reduction in adhesions and tissue fibrosis in this study. Because surgically lesioned sites had no adhesions to other lesioned sites, the effects of GnRH-a and Interceed on healing could be evaluated independently. Differences in results from animal to animal variation were minimized in this model because each rabbit served as its own internal control. The mechanism for the GnRH-a–induced reduction of adhesions is not clear, but recent studies have provided evidence that hypoestrogenism can modify the inflammatory response or alter tissue remodeling (7). Interceed alone did not reduce adhesions in our animal model, possibly because of the mild degree of trauma induced by the three uterine manipulations used. Although absolute hemostasis was established before placing the Interceed, it is possible that a small amount of blood at the abrasion site reduced the effectiveness of Interceed (8). Perhaps the inclusion of more rabbits per test group or the use of more traumatic lesioning would have resulted in the detection of a preventive effect of Interceed on postoperative adhesions.
GnRH-agonist and Interceed for adhesions
Vol. 81, No. 1, January 2004
Under the conditions of this study, however, GnRH-a reduced the presence of postoperative adhesions, whereas Interceed did not. Even when macroscopic adhesions do not form, tissue fibrosis may result in organ dysfunction. Grossly normal fallopian tubes from patients with ectopic pregnancies are found to have microscopic evidence of inflammatory change (9). We believe that interventions that reduce tissue fibrosis may enhance the effectiveness of reproductive surgery. In conclusion, GnRH-a pretreatment decreases adhesions, whereas no benefit is seen with Interceed alone. However, adhesions and fibrosis are both reduced when GnRH-a is combined with Interceed. Further study is needed to determine whether GnRH-a pretreatment, alone or in combination with adhesion barriers, enhances reproductive surgery in women.
Acknowledgments: The expert advice and work of Terry Loeb (Carolinas Medical Center) on study design are gratefully acknowledged. The administrative and manuscript preparation was expertly performed by Lillian Lawrence (Carolinas Medical Center).
FERTILITY & STERILITY威
References 1. Mais V, Ajossa S, Piras B, Guerriero S, Marongiu D, Melis GB. Prevention of de novo adhesion formation after laparoscopic myomectomy: a randomized trial to evaluate the effectiveness of an oxidized regenerated cellulose absorbable barrier. Hum Reprod 1995; 10:3133–5. 2. Grow DR, Coddington CC, Hsiu JG, Mikich Y, Hodgen GD. Role of hypoestrogenism or sex steroid antagonism in adhesion formation after myometrial surgery in primates. Fertil Steril 1996;66:140 –6. 3. Boyers SP, Diamond MP, DeCherney AH. Reduction of postoperative pelvic adhesions in the rabbit with Gore-Tex surgical membrane. Fertil Steril 1988;49:1066 –70. 4. Zanagnolo V, Dharmarajan AM, Hesla J, Wallach EE. Effects of gonadotropin releasing hormone analog on rabbit ovarian function. Endocrinology 1996;137:5400 –6. 5. Cross SS. Grading and scoring in histopathology. Histopathology 1998; 33:99 –106. 6. Diggle PJ, Liang KY, Zeger LL. Analysis of longitudinal data. Oxford, United Kingdom: Oxford Science Publications, 1995. 7. Sharpe-Timms KL, Zimmer RL, Jolliff WJ, Wright JA, Nothnick WB, Curry TE. Gonadotropin-releasing hormone agonist (GnRH-a) therapy alters activity of plasminogen activators, matrix metalloproteinases, and their inhibitors in rat models for adhesion formation and endometriosis: potential GnRH-a-regulated mechanisms reducing adhesion formation. Fertil Steril 1998;69:916 –23. 8. Wiseman DM, Gottlick-Iarkowski L, Kamp L. Effect of different barriers of oxidized regenerated cellulose (ORC) on cecal and sidewall adhesions in the presence and absence of bleeding. J Invest Surg 1999; 12:141–6. 9. Cumming DC, Honore LH, Scott JZ, Williams KE. Microscopic evidence of silent inflammation in grossly normal fallopian tubes with ectopic pregnancy. Int J Fertil 1988;33:324 –8.
197