Cesarean Delivery: Original Research
Cesarean Delivery Times and Adhesion Severity Associated With Prior Placement of a Sodium Hyaluronate-Carboxycellulose Barrier Maria Gaspar-Oishi,
MD
and Tod Aeby,
MD, MEd
OBJECTIVE: To evaluate the association between the prior use of a sodium hyaluronate-carboxycellulose adhesion barrier and the incision-to-delivery time and adhesion scores at first repeat cesarean delivery. METHODS: In this cohort study, intraoperative data were prospectively collected at the time of the study participants’ first repeat cesarean delivery. Subsequent retrospective chart review of each patient’s primary cesarean operative note was then performed to determine whether hyaluronate-carboxycellulose barrier film had been used. The primary outcome was incision-todelivery time. Secondary outcomes were adhesion grade and blood loss. RESULTS: A total of 97 patients were analyzed; 71 did not have hyaluronate-carboxycellulose barrier film used during their primary cesarean and 26 did. Mean6standard deviation incision-to-delivery time was 9.564.3 minutes in the no hyaluronate-carboxycellulose barrier film group and 10.665.8 minutes in the hyaluronate-carboxycellulose barrier film group (P5.8). Average blood loss was 5646255 mL and 5636246 mL, respectively (P5.4). There was no difference between the mean fascia adhesion scores (1.45 compared with 1.31 Z 21.06, P5.29) and mean intraperitoneal adhesion scores (1.11 compared with 0.92 Z 21.09, P5.27). Our sample size yielded a power of From the University of Hawaii John A. Burns School of Medicine, Department of Obstetrics, Gynecology and Women’s Health, Honolulu, Hawaii. Presented at the Annual Clinical and Scientific Meeting of the American College of Obstetricians and Gynecologists, April 26–30, 2014, Chicago, Illinois. Corresponding author: Maria Gaspar-Oishi, MD, University of Hawaii John A. Burns School of Medicine, Department of Obstetrics, Gynecology and Women’s Health, 1319 Punahou Street, Suite 824, Honolulu, HI 96826; e-mail: [email protected]. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14
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91% to detect a 5-minute difference in delivery times and 99% for a 1-point difference in adhesion scores. CONCLUSION: Our study showed no difference in the delivery time, blood loss, or adhesion scores at first repeat cesarean delivery between women who had hyaluronatecarboxycellulose barrier film placed at the time of their primary cesarean delivery and those who did not. (Obstet Gynecol 2014;124:679–83) DOI: 10.1097/AOG.0000000000000450
LEVEL OF EVIDENCE: II
P
ostoperative adhesions are the result of tissue trauma and subsequent healing. Tissue trauma triggers a cascade of events resulting in release of histamine and kinins that result in fibrin deposits. In normal tissue healing, this fibrin exudate is broken down within 72 hours; however, when there is decreased fibrinolytic activity, this fibrin exudate remains and adhesion formation occurs.1,2 Adhesions are a known cause of infertility, bowel obstruction, and abdominal and pelvic pain and are associated with increased health care costs.1,3,4 In obstetrics, adhesions are of particular importance, especially in the setting of repeat cesarean deliveries, which have been shown to be associated with increased adhesion development and delivery time.5,6 Of the adhesion barriers available today, only two have been studied specifically in the setting of cesarean deliveries: Interceed (a barrier consisting of oxidized regenerated cellulose) and Seprafilm (a membrane made of sodium hyaluronate-carboxycellulose).7 The two products function similarly by acting as a mechanical barrier against adhesion formation.8 Hyaluronate-carboxycellulose barrier film is of particular interest to our group, because it is used in almost 40% of the cesarean deliveries in our institution. The cost of the barrier film (at an institutional cost of $200
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per sheet) and the paucity of data supporting the efficacy of its use were the impetus for this study.
Table 1. Adhesion Grading for the Level of the Rectus Fascia
MATERIALS AND METHODS
Grade
We conducted this cohort study to determine the effect of hyaluronate-carboxycellulose barrier film on the incision-to-delivery interval and adhesion formation in the setting of the first repeat cesarean deliveries. The trial was conducted between January 2011 and September 2013 in the labor and delivery unit of the Kapiolani Medical Center for Women’s and Children, a tertiary care referral hospital and the main obstetric teaching institution for the University of Hawaii, John A. Burns School of Medicine. Approval for this investigation came from the western institutional review board. Patients undergoing a first repeat cesarean delivery were approached. Women were eligible if they were older than 18 years of age, able to give consent, and if the patient’s physician was a member of the University of Hawaii full-time or clinical faculty. Patients were excluded for a history of pelvic inflammatory disease or any prior laparoscopic or open abdominal or pelvic surgery. Patients were also excluded if clinical circumstances required urgent performance of the repeat cesarean delivery. Written consent was obtained and all surgeries were performed by a resident directly supervised by a faculty attending physician. Once a patient was enrolled in the study, the surgical team was instructed to not refer to the operative note of the primary cesarean delivery, effectively blinding the surgeons to whether an adhesion barrier was used. At the time of the first repeat cesarean delivery, the following prospective data were collected: patient demographics, level of resident performing the surgery, delivery time (defined as lapsed time between the skin incision and the delivery of the neonate), estimated blood loss, and adhesion grades at the fascia and peritoneal level. Resident level was reported in months of training. Two adhesion grades were assigned by the resident performing the surgery, one for adhesions at the level of the fascia and another for adhesions at the peritoneal level. Adhesion grades were modeled after a similar study performed by Chapa et al.9 All of the residents at the University of Hawaii obstetrics and gynecology residency training program underwent training modules to ensure standardization of the grading system (Tables 1 and 2). After the prospective data were collected (for the repeat cesarean delivery), a single investigator performed a chart review of each patient’s primary cesarean operative note to determine whether hyaluronatecarboxycellulose barrier film was used. At the time of the chart review, patients were further excluded if the
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0
1
2
3
Description Planes between fascia, rectus muscles, and peritoneal layer easily separable—similar to a primary cesarean delivery Filmy adhesions between fascia and rectus muscles and peritoneal layer, minimal amount of dissection needed Dense adhesions between fascia and rectus muscles and peritoneal layer adhesions, moderate amount of dissection needed Rectus muscles completely adhered to uterus, extensive dissection needed
aforementioned exclusionary criteria were discovered or if the operative note from the primary cesarean delivery could not be obtained. The investigators and the residents who performed the repeat cesarean delivery, and thus the adhesion grading, were blinded to the operative note from the primary cesarean delivery. Sample size was calculated based on a study performed by Chapa et al9 using a similar adhesion barrier. They found that the mean (6standard deviation) incision-to-delivery time for a repeat cesarean delivery without the adhesion barrier was 15.7 (66.5) minutes, whereas with the adhesion barrier prevention. it was 10.2 (63.3) minutes. We calculated a need for a minimum of 56 patients to have an 80% chance of demonstrating a 5minute difference in delivery time at the .05 level of significance assuming a standard deviation of 6.5. The incision-to-delivery time, estimated blood loss, resident level, and the demographic data were not normally distributed, and so groups (with and without the hyaluronate-carboxycellulose barrier film) were compared using a nonparametric Wilcoxon test. Likewise, ordinal data were also compared using the Wilcoxon test. All tests were two-sided and P,.05 was considered significant. All data were analyzed using JMP Pro 11 JMP 11.0.0.
RESULTS A total of 106 patients were initially approached, but two had a history of abdominal or pelvic surgery Table 2. Adhesion Grading for the Peritoneal Level Grade 0 1 2 3
Description No adhesions Minimal or filmy adhesions Moderate or thick adhesions Absence of free space between uterus and anterior abdominal wall
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(and so were not included) and four declined study participation (Fig. 1). After further chart review, three more patients were excluded, two as a result of previously undisclosed abdominal or pelvic surgery and one as a result of the use of a different adhesion barrier (oxidized regenerated cellulose barrier) at the primary cesarean delivery. Thus, 97 women comprised our cohort: remained in 71 in the no hyaluronatecarboxycellulose barrier film group and 26 in the hyaluronate-carboxycellulose barrier film group. The two groups were similar with respect to maternal age, body mass index, parity, and gestational age at the time of the cesarean delivery (Table 3). Review of the operative notes of the 26 patients who had hyaluronatecarboxycellulose barrier membrane use in the primary cesarean delivery revealed the following: 16 had a hyaluronate-carboxycellulose barrier membrane placed directly on the hysterotomy, one had a hyaluronatecarboxycellulose barrier placed above the fascia, and nine had a hyaluronate-carboxycellulose barrier membrane placed both at the hysterotomy and above the fascia. Approximately 80% of all patients in both groups were of Asian American descent, which mirrors the ethnic distribution of Hawaii as a state. Our primary outcome measure was the time from skin incision to delivery of the neonate. There was no significant difference between the no
hyaluronate-carboxycellulose barrier film group and the hyaluronate-carboxycellulose barrier film group (9.564.3 minutes compared with 10.665.8 minutes, P5.8; Table 4). Experience level of the resident assistant was evaluated as a potential confounding factor and we did not find a statistically or clinically significant difference in the resident level between the two groups (P5.14; Table 4). Our secondary outcomes were estimated blood loss and adhesion severity. Mean6standard deviation estimated blood loss was 5646255 mL in the no hyaluronate-carboxycellulose barrier film group and 5636246 mL in the hyaluronate-carboxycellulose barrier film group (P5.4). There was no significant difference between mean fascial adhesion scores, 1.456 0.7 compared with 1.3160.7 (Wilcoxon, Z 21.06, P5.29) or mean intraperitoneal adhesion score: 1.1160.8 compared with 0.9260.8 (Wilcoxon, Z 21.09, P5.27) between the two groups (Table 5).
DISCUSSION We found that hyaluronate-carboxycellulose barrier film use during a primary cesarean delivery was not associated with adhesion severity in the subsequent repeat cesarean delivery. More importantly, hyaluronate-carboxycellulose barrier film use was not associated with decreased blood loss
Fig. 1. Study design and sample size. Gaspar-Oishi. Cesarean Delivery Times and Adhesion Severity. Obstet Gynecol 2014.
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Table 3. Patient Demographics Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery (N597) Characteristic
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
P
Location
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
31.765.6 33.666.5 1 (1–6) 38.061.8
29.466.5 35.969.2 1 (1–8) 37.962.0
.05 .87 .55 .40
Fascia Peritoneal
1.4560.7 1.1160.8
1.3160.7 0.9260.8
63/71 (0.89) 8/71 (0.11)
20/26 (0.77) 6/26 (0.23)
.14 .14
Age (y) BMI (kg/m2) Parity Gestational age (wk) Race and ethnicity Asian Non-Asian
HA-CC, hyaluronate-carboxycellulose; BMI, body mass index. Data are mean6standard deviation, median (range), or n/N (%) unless otherwise specified.
or shorter incision-to-delivery time. Our results are not concordant with findings of Fushiki et al,10 which is the study the industry uses to support its use and only other prospective study that has looked at hyaluronatecarboxycellulose barrier film use in cesarean deliveries. Their study evaluated incision-to-delivery times and the presence and severity of adhesions prospectively at time of repeat cesarean delivery and concluded that the time from skin incision to the delivery of the neonate was significantly less in the hyaluronate-carboxycellulose barrier film group compared with the no barrier group.10 The study also showed that the adhesion incidence and severity were significantly lower in the hyaluronate-carboxycellulose barrier film group compared with the no barrier group.10 On further analysis of this study, several key differences in the study design were noted, which may explain our contrasting findings. The sample size (27 in each group) was smaller than ours and the study was not blinded (nor randomized). The prospective, standardization of adhesion scores and routine training modules were strengths of our study. The blinded nature of our study resulted in minimized Table 4. Incision-to-Delivery Time, Blood Loss, and Resident Level Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery Results Incision-to-delivery time (min) EBL (mL) Resident level (mo)
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
P
9.564.3
10.665.8
.80
5646255 25.1611.1
5636246 22.0612.6
.49 .14
HA-CC, hyaluronate-carboxycellulose; EBL, estimated blood loss. Data are mean6standard deviation unless otherwise specified.
682
Table 5. Adhesion Scores Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery
Gaspar-Oishi and Aeby
Z
P
21.06 .29 21.09 .27
HA-CC, hyaluronate-carboxycellulose. Data are mean6standard deviation on a 0- to 3-point scale unless otherwise specified.
bias and a more accurate comparison of the use compared with no use of hyaluronate-carboxycellulose barrier film. A limitation of our study is that there were more patients in the no hyaluronate-carboxycellulose barrier film group. Whereas unequal sample sizes had a modest effect on the power of the study, recruiting more patients offset this. Using the actual sample sizes and a standard deviation of 5.8, we calculate that we had a 96% chance of demonstrating a mean 5-minute difference in delivery time, if one existed. Although we made a rigorous attempt at excluding patients who had previous abdominal surgery and pelvic inflammatory disease, we acknowledge the limitation of patient history recollection and chart review. Previous treatments and surgeries could have been missed if the patient did not recall these and they were performed at a different institution. Although the Asian ethnic majority of our study groups reflects that of the state of Hawaii, repeating the study with a more diverse population would allow for more generalized conclusions. The limited amount of data supporting the efficacy of hyaluronate-carboxycellulose barrier film use is concerning, because this product is extensively used in cesarean deliveries and is advertised prevalently in obstetrics and gynecology specialty journals. In our institution alone, with more than 6,000 births a year and a primary cesarean delivery rate of 19%, we estimate that hyaluronate-carboxycellulose barrier film is used in approximately 30–40% of all cesarean deliveries. Its use is associated with increased cost, because each sheet costs the institution $200 and patient costs are certainly higher.11 A recent commentary echoes our concerns: Albright et al aptly stated “the use of adhesion barriers at cesarean deliveries is ill-advised at the present time. The very limited data on the use of such barriers at cesarean delivery fail to support any meaningful short-term clinical benefit..”12 Indeed, the results of our study mirror Albright’s conclusions. At this time, our data do not support the use of hyaluronate-carboxycellulose barrier membranes in cesarean deliveries given the added cost and no demonstrable clinical benefit for the patient.
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REFERENCES 1. Practice Committee of American Society for Reproductive Medicine in collaboration with Society of Reproductive Surgeons. Pathogenesis, consequences, and control of peritoneal adhesions in gynecologic surgery: a committee opinion. Fertil Steril 2013;99:1550–5. 2. Awonuga AO, Fletcher NM, Saed GM, Diamond MP. Postoperative adhesion development following cesarean and open intra-abdominal gynecological operations: a review. Reprod Sci 2011;18:1166–85. 3. Diamond MP, Freeman ML. Clinical implications of postsurgical adhesions. Hum Reprod Update 2001;7:567–76.
7. Bates GW Jr, Shomento S. Adhesion prevention in patients with multiple cesarean deliveries. Am J Obstet Gynecol 2011; 205(suppl):S19–24. 8. Ahmad G, Duffy JM, Farquhar C, Vail A, Vandekerckhove P, Watson A, et al. Barrier agents for adhesion prevention after gynaecological surgery. The Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD000475. DOI: 10.1002/14651858.CD000475. pub2. 9. Chapa HO, Venegas G, Vanduyne CP, Antonetti AG, Sandate JP, Silver L. Peritoneal adhesion prevention at cesarean section: an analysis of the effectiveness of an absorbable adhesion barrier. J Reprod Med 2011;56: 103–9.
4. Lower AM, Hawthorn RJ, Ellis H, O’Brien F, Buchan S, Crowe AM. The impact of adhesions on hospital readmissions over ten years after 8849 open gynaecological operations: an assessment from the Surgical and Clinical Adhesions Research Study. BJOG 2000;107:855–62.
10. Fushiki H, Ikoma T, Kobayashi H, Yoshimoto H. Efficacy of Seprafilm as an adhesion prevention barrier in cesarean sections. Obstet Gynecol Treat 2005;91:557–61.
5. Morales KJ, Gordon MC, Bates GW Jr. Postcesarean delivery adhesions associated with delayed delivery of infant. Am J Obstet Gynecol 2007;196:461.e1–6.
11. Surgical V. Genzyme: Seprafilm 4301-02. 2013. Available at: http://www.valleysurg.com/genzyme-4301-02.html. Retrieved November 17, 2013.
6. Tulandi T, Agdi M, Zarei A, Miner L, Sikirica V. Adhesion development and morbidity after repeat cesarean delivery. Am J Obstet Gynecol 2009;201:56.e1–6.
12. Albright CM, Rouse DJ. Adhesion barriers at cesarean delivery: advertising compared with the evidence. Obstet Gynecol 2011;118:003157–60.
Continuing Medical Education Credits Available for the Clinical Expert Series Continuing medical education (CME) credits for reading the Clinical Expert Series are available through joint sponsorship with The American College of Obstetricians and Gynecologists. Visit http://www.greenjournal.org and click on the “CME” tab to get started. ACCME Accreditation The American College of Obstetricians and Gynecologists is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. AMA PRA Category 1 Credit(s)™ The American College of Obstetricians and Gynecologists designates this enduring material for a maximum of 2 AMA PRA Category 1 Credits.™ Physicians should claim only the credit commensurate with the extent of their participation in the activity. College Cognate Credit(s) The American College of Obstetricians and Gynecologists designates this enduring material for a maximum of 2 Category 1 College Cognate Credits. The College has a reciprocity agreement with the AMA that allows AMA PRA Category 1 Credits™ to be equivalent to College Cognate Credits. rev 3/2014
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Cesarean Delivery Times and Adhesion Severity Associated With Prior Placement of a Sodium Hyaluronate-Carboxycellulose Barrier Maria Gaspar-Oishi,
MD
and Tod Aeby,
MD, MEd
OBJECTIVE: To evaluate the association between the prior use of a sodium hyaluronate-carboxycellulose adhesion barrier and the incision-to-delivery time and adhesion scores at first repeat cesarean delivery. METHODS: In this cohort study, intraoperative data were prospectively collected at the time of the study participants’ first repeat cesarean delivery. Subsequent retrospective chart review of each patient’s primary cesarean operative note was then performed to determine whether hyaluronate-carboxycellulose barrier film had been used. The primary outcome was incision-todelivery time. Secondary outcomes were adhesion grade and blood loss. RESULTS: A total of 97 patients were analyzed; 71 did not have hyaluronate-carboxycellulose barrier film used during their primary cesarean and 26 did. Mean6standard deviation incision-to-delivery time was 9.564.3 minutes in the no hyaluronate-carboxycellulose barrier film group and 10.665.8 minutes in the hyaluronate-carboxycellulose barrier film group (P5.8). Average blood loss was 5646255 mL and 5636246 mL, respectively (P5.4). There was no difference between the mean fascia adhesion scores (1.45 compared with 1.31 Z 21.06, P5.29) and mean intraperitoneal adhesion scores (1.11 compared with 0.92 Z 21.09, P5.27). Our sample size yielded a power of From the University of Hawaii John A. Burns School of Medicine, Department of Obstetrics, Gynecology and Women’s Health, Honolulu, Hawaii. Presented at the Annual Clinical and Scientific Meeting of the American College of Obstetricians and Gynecologists, April 26–30, 2014, Chicago, Illinois. Corresponding author: Maria Gaspar-Oishi, MD, University of Hawaii John A. Burns School of Medicine, Department of Obstetrics, Gynecology and Women’s Health, 1319 Punahou Street, Suite 824, Honolulu, HI 96826; e-mail: [email protected]. Financial Disclosure The authors did not report any potential conflicts of interest. © 2014 by The American College of Obstetricians and Gynecologists. Published by Lippincott Williams & Wilkins. ISSN: 0029-7844/14
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91% to detect a 5-minute difference in delivery times and 99% for a 1-point difference in adhesion scores. CONCLUSION: Our study showed no difference in the delivery time, blood loss, or adhesion scores at first repeat cesarean delivery between women who had hyaluronatecarboxycellulose barrier film placed at the time of their primary cesarean delivery and those who did not. (Obstet Gynecol 2014;124:679–83) DOI: 10.1097/AOG.0000000000000450
LEVEL OF EVIDENCE: II
P
ostoperative adhesions are the result of tissue trauma and subsequent healing. Tissue trauma triggers a cascade of events resulting in release of histamine and kinins that result in fibrin deposits. In normal tissue healing, this fibrin exudate is broken down within 72 hours; however, when there is decreased fibrinolytic activity, this fibrin exudate remains and adhesion formation occurs.1,2 Adhesions are a known cause of infertility, bowel obstruction, and abdominal and pelvic pain and are associated with increased health care costs.1,3,4 In obstetrics, adhesions are of particular importance, especially in the setting of repeat cesarean deliveries, which have been shown to be associated with increased adhesion development and delivery time.5,6 Of the adhesion barriers available today, only two have been studied specifically in the setting of cesarean deliveries: Interceed (a barrier consisting of oxidized regenerated cellulose) and Seprafilm (a membrane made of sodium hyaluronate-carboxycellulose).7 The two products function similarly by acting as a mechanical barrier against adhesion formation.8 Hyaluronate-carboxycellulose barrier film is of particular interest to our group, because it is used in almost 40% of the cesarean deliveries in our institution. The cost of the barrier film (at an institutional cost of $200
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679
per sheet) and the paucity of data supporting the efficacy of its use were the impetus for this study.
Table 1. Adhesion Grading for the Level of the Rectus Fascia
MATERIALS AND METHODS
Grade
We conducted this cohort study to determine the effect of hyaluronate-carboxycellulose barrier film on the incision-to-delivery interval and adhesion formation in the setting of the first repeat cesarean deliveries. The trial was conducted between January 2011 and September 2013 in the labor and delivery unit of the Kapiolani Medical Center for Women’s and Children, a tertiary care referral hospital and the main obstetric teaching institution for the University of Hawaii, John A. Burns School of Medicine. Approval for this investigation came from the western institutional review board. Patients undergoing a first repeat cesarean delivery were approached. Women were eligible if they were older than 18 years of age, able to give consent, and if the patient’s physician was a member of the University of Hawaii full-time or clinical faculty. Patients were excluded for a history of pelvic inflammatory disease or any prior laparoscopic or open abdominal or pelvic surgery. Patients were also excluded if clinical circumstances required urgent performance of the repeat cesarean delivery. Written consent was obtained and all surgeries were performed by a resident directly supervised by a faculty attending physician. Once a patient was enrolled in the study, the surgical team was instructed to not refer to the operative note of the primary cesarean delivery, effectively blinding the surgeons to whether an adhesion barrier was used. At the time of the first repeat cesarean delivery, the following prospective data were collected: patient demographics, level of resident performing the surgery, delivery time (defined as lapsed time between the skin incision and the delivery of the neonate), estimated blood loss, and adhesion grades at the fascia and peritoneal level. Resident level was reported in months of training. Two adhesion grades were assigned by the resident performing the surgery, one for adhesions at the level of the fascia and another for adhesions at the peritoneal level. Adhesion grades were modeled after a similar study performed by Chapa et al.9 All of the residents at the University of Hawaii obstetrics and gynecology residency training program underwent training modules to ensure standardization of the grading system (Tables 1 and 2). After the prospective data were collected (for the repeat cesarean delivery), a single investigator performed a chart review of each patient’s primary cesarean operative note to determine whether hyaluronatecarboxycellulose barrier film was used. At the time of the chart review, patients were further excluded if the
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0
1
2
3
Description Planes between fascia, rectus muscles, and peritoneal layer easily separable—similar to a primary cesarean delivery Filmy adhesions between fascia and rectus muscles and peritoneal layer, minimal amount of dissection needed Dense adhesions between fascia and rectus muscles and peritoneal layer adhesions, moderate amount of dissection needed Rectus muscles completely adhered to uterus, extensive dissection needed
aforementioned exclusionary criteria were discovered or if the operative note from the primary cesarean delivery could not be obtained. The investigators and the residents who performed the repeat cesarean delivery, and thus the adhesion grading, were blinded to the operative note from the primary cesarean delivery. Sample size was calculated based on a study performed by Chapa et al9 using a similar adhesion barrier. They found that the mean (6standard deviation) incision-to-delivery time for a repeat cesarean delivery without the adhesion barrier was 15.7 (66.5) minutes, whereas with the adhesion barrier prevention. it was 10.2 (63.3) minutes. We calculated a need for a minimum of 56 patients to have an 80% chance of demonstrating a 5minute difference in delivery time at the .05 level of significance assuming a standard deviation of 6.5. The incision-to-delivery time, estimated blood loss, resident level, and the demographic data were not normally distributed, and so groups (with and without the hyaluronate-carboxycellulose barrier film) were compared using a nonparametric Wilcoxon test. Likewise, ordinal data were also compared using the Wilcoxon test. All tests were two-sided and P,.05 was considered significant. All data were analyzed using JMP Pro 11 JMP 11.0.0.
RESULTS A total of 106 patients were initially approached, but two had a history of abdominal or pelvic surgery Table 2. Adhesion Grading for the Peritoneal Level Grade 0 1 2 3
Description No adhesions Minimal or filmy adhesions Moderate or thick adhesions Absence of free space between uterus and anterior abdominal wall
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(and so were not included) and four declined study participation (Fig. 1). After further chart review, three more patients were excluded, two as a result of previously undisclosed abdominal or pelvic surgery and one as a result of the use of a different adhesion barrier (oxidized regenerated cellulose barrier) at the primary cesarean delivery. Thus, 97 women comprised our cohort: remained in 71 in the no hyaluronatecarboxycellulose barrier film group and 26 in the hyaluronate-carboxycellulose barrier film group. The two groups were similar with respect to maternal age, body mass index, parity, and gestational age at the time of the cesarean delivery (Table 3). Review of the operative notes of the 26 patients who had hyaluronatecarboxycellulose barrier membrane use in the primary cesarean delivery revealed the following: 16 had a hyaluronate-carboxycellulose barrier membrane placed directly on the hysterotomy, one had a hyaluronatecarboxycellulose barrier placed above the fascia, and nine had a hyaluronate-carboxycellulose barrier membrane placed both at the hysterotomy and above the fascia. Approximately 80% of all patients in both groups were of Asian American descent, which mirrors the ethnic distribution of Hawaii as a state. Our primary outcome measure was the time from skin incision to delivery of the neonate. There was no significant difference between the no
hyaluronate-carboxycellulose barrier film group and the hyaluronate-carboxycellulose barrier film group (9.564.3 minutes compared with 10.665.8 minutes, P5.8; Table 4). Experience level of the resident assistant was evaluated as a potential confounding factor and we did not find a statistically or clinically significant difference in the resident level between the two groups (P5.14; Table 4). Our secondary outcomes were estimated blood loss and adhesion severity. Mean6standard deviation estimated blood loss was 5646255 mL in the no hyaluronate-carboxycellulose barrier film group and 5636246 mL in the hyaluronate-carboxycellulose barrier film group (P5.4). There was no significant difference between mean fascial adhesion scores, 1.456 0.7 compared with 1.3160.7 (Wilcoxon, Z 21.06, P5.29) or mean intraperitoneal adhesion score: 1.1160.8 compared with 0.9260.8 (Wilcoxon, Z 21.09, P5.27) between the two groups (Table 5).
DISCUSSION We found that hyaluronate-carboxycellulose barrier film use during a primary cesarean delivery was not associated with adhesion severity in the subsequent repeat cesarean delivery. More importantly, hyaluronate-carboxycellulose barrier film use was not associated with decreased blood loss
Fig. 1. Study design and sample size. Gaspar-Oishi. Cesarean Delivery Times and Adhesion Severity. Obstet Gynecol 2014.
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Table 3. Patient Demographics Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery (N597) Characteristic
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
P
Location
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
31.765.6 33.666.5 1 (1–6) 38.061.8
29.466.5 35.969.2 1 (1–8) 37.962.0
.05 .87 .55 .40
Fascia Peritoneal
1.4560.7 1.1160.8
1.3160.7 0.9260.8
63/71 (0.89) 8/71 (0.11)
20/26 (0.77) 6/26 (0.23)
.14 .14
Age (y) BMI (kg/m2) Parity Gestational age (wk) Race and ethnicity Asian Non-Asian
HA-CC, hyaluronate-carboxycellulose; BMI, body mass index. Data are mean6standard deviation, median (range), or n/N (%) unless otherwise specified.
or shorter incision-to-delivery time. Our results are not concordant with findings of Fushiki et al,10 which is the study the industry uses to support its use and only other prospective study that has looked at hyaluronatecarboxycellulose barrier film use in cesarean deliveries. Their study evaluated incision-to-delivery times and the presence and severity of adhesions prospectively at time of repeat cesarean delivery and concluded that the time from skin incision to the delivery of the neonate was significantly less in the hyaluronate-carboxycellulose barrier film group compared with the no barrier group.10 The study also showed that the adhesion incidence and severity were significantly lower in the hyaluronate-carboxycellulose barrier film group compared with the no barrier group.10 On further analysis of this study, several key differences in the study design were noted, which may explain our contrasting findings. The sample size (27 in each group) was smaller than ours and the study was not blinded (nor randomized). The prospective, standardization of adhesion scores and routine training modules were strengths of our study. The blinded nature of our study resulted in minimized Table 4. Incision-to-Delivery Time, Blood Loss, and Resident Level Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery Results Incision-to-delivery time (min) EBL (mL) Resident level (mo)
No HA-CC Barrier (n571)
HA-CC Barrier (n526)
P
9.564.3
10.665.8
.80
5646255 25.1611.1
5636246 22.0612.6
.49 .14
HA-CC, hyaluronate-carboxycellulose; EBL, estimated blood loss. Data are mean6standard deviation unless otherwise specified.
682
Table 5. Adhesion Scores Stratified by Hyaluronate-Carboxycellulose Barrier Use in Primary Cesarean Delivery
Gaspar-Oishi and Aeby
Z
P
21.06 .29 21.09 .27
HA-CC, hyaluronate-carboxycellulose. Data are mean6standard deviation on a 0- to 3-point scale unless otherwise specified.
bias and a more accurate comparison of the use compared with no use of hyaluronate-carboxycellulose barrier film. A limitation of our study is that there were more patients in the no hyaluronate-carboxycellulose barrier film group. Whereas unequal sample sizes had a modest effect on the power of the study, recruiting more patients offset this. Using the actual sample sizes and a standard deviation of 5.8, we calculate that we had a 96% chance of demonstrating a mean 5-minute difference in delivery time, if one existed. Although we made a rigorous attempt at excluding patients who had previous abdominal surgery and pelvic inflammatory disease, we acknowledge the limitation of patient history recollection and chart review. Previous treatments and surgeries could have been missed if the patient did not recall these and they were performed at a different institution. Although the Asian ethnic majority of our study groups reflects that of the state of Hawaii, repeating the study with a more diverse population would allow for more generalized conclusions. The limited amount of data supporting the efficacy of hyaluronate-carboxycellulose barrier film use is concerning, because this product is extensively used in cesarean deliveries and is advertised prevalently in obstetrics and gynecology specialty journals. In our institution alone, with more than 6,000 births a year and a primary cesarean delivery rate of 19%, we estimate that hyaluronate-carboxycellulose barrier film is used in approximately 30–40% of all cesarean deliveries. Its use is associated with increased cost, because each sheet costs the institution $200 and patient costs are certainly higher.11 A recent commentary echoes our concerns: Albright et al aptly stated “the use of adhesion barriers at cesarean deliveries is ill-advised at the present time. The very limited data on the use of such barriers at cesarean delivery fail to support any meaningful short-term clinical benefit..”12 Indeed, the results of our study mirror Albright’s conclusions. At this time, our data do not support the use of hyaluronate-carboxycellulose barrier membranes in cesarean deliveries given the added cost and no demonstrable clinical benefit for the patient.
Cesarean Delivery Times and Adhesion Severity
OBSTETRICS & GYNECOLOGY
REFERENCES 1. Practice Committee of American Society for Reproductive Medicine in collaboration with Society of Reproductive Surgeons. Pathogenesis, consequences, and control of peritoneal adhesions in gynecologic surgery: a committee opinion. Fertil Steril 2013;99:1550–5. 2. Awonuga AO, Fletcher NM, Saed GM, Diamond MP. Postoperative adhesion development following cesarean and open intra-abdominal gynecological operations: a review. Reprod Sci 2011;18:1166–85. 3. Diamond MP, Freeman ML. Clinical implications of postsurgical adhesions. Hum Reprod Update 2001;7:567–76.
7. Bates GW Jr, Shomento S. Adhesion prevention in patients with multiple cesarean deliveries. Am J Obstet Gynecol 2011; 205(suppl):S19–24. 8. Ahmad G, Duffy JM, Farquhar C, Vail A, Vandekerckhove P, Watson A, et al. Barrier agents for adhesion prevention after gynaecological surgery. The Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD000475. DOI: 10.1002/14651858.CD000475. pub2. 9. Chapa HO, Venegas G, Vanduyne CP, Antonetti AG, Sandate JP, Silver L. Peritoneal adhesion prevention at cesarean section: an analysis of the effectiveness of an absorbable adhesion barrier. J Reprod Med 2011;56: 103–9.
4. Lower AM, Hawthorn RJ, Ellis H, O’Brien F, Buchan S, Crowe AM. The impact of adhesions on hospital readmissions over ten years after 8849 open gynaecological operations: an assessment from the Surgical and Clinical Adhesions Research Study. BJOG 2000;107:855–62.
10. Fushiki H, Ikoma T, Kobayashi H, Yoshimoto H. Efficacy of Seprafilm as an adhesion prevention barrier in cesarean sections. Obstet Gynecol Treat 2005;91:557–61.
5. Morales KJ, Gordon MC, Bates GW Jr. Postcesarean delivery adhesions associated with delayed delivery of infant. Am J Obstet Gynecol 2007;196:461.e1–6.
11. Surgical V. Genzyme: Seprafilm 4301-02. 2013. Available at: http://www.valleysurg.com/genzyme-4301-02.html. Retrieved November 17, 2013.
6. Tulandi T, Agdi M, Zarei A, Miner L, Sikirica V. Adhesion development and morbidity after repeat cesarean delivery. Am J Obstet Gynecol 2009;201:56.e1–6.
12. Albright CM, Rouse DJ. Adhesion barriers at cesarean delivery: advertising compared with the evidence. Obstet Gynecol 2011;118:003157–60.
Continuing Medical Education Credits Available for the Clinical Expert Series Continuing medical education (CME) credits for reading the Clinical Expert Series are available through joint sponsorship with The American College of Obstetricians and Gynecologists. Visit http://www.greenjournal.org and click on the “CME” tab to get started. ACCME Accreditation The American College of Obstetricians and Gynecologists is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. AMA PRA Category 1 Credit(s)™ The American College of Obstetricians and Gynecologists designates this enduring material for a maximum of 2 AMA PRA Category 1 Credits.™ Physicians should claim only the credit commensurate with the extent of their participation in the activity. College Cognate Credit(s) The American College of Obstetricians and Gynecologists designates this enduring material for a maximum of 2 Category 1 College Cognate Credits. The College has a reciprocity agreement with the AMA that allows AMA PRA Category 1 Credits™ to be equivalent to College Cognate Credits. rev 3/2014
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