Okay, now that we know why some obs and midwives want to deny women the right to vbac based on suturing, let's look at some articles that don't report a difference in the rate of UR in single vs double layer (oh, by the way - there are a LOT more of them!)
Unfortunately I do not have full studies for all of them (I noted whether I had the full study or just the abstract at the beginning of each summary). As I find more studies, I will add them in.
Remember that it appears that suturing type and technique as well as surgeon skill have a lot to do with UR risks! The research suggests that non-locking polyglactin (0-Vicrul) sutures are the best.
STUDY 1 - I reviewed the FULL STUDY
Uterine rupture, perioperative and perinatal morbidity after single-layer and double-layer closure at cesarean delivery
American Journal of Obstetrics and Gynecology Volume 189, Issue 4, Pages 925-929 (October 2003)
authors: Celeste Durnwald, MD, Brian Mercer, MD
Cleveland, Ohio
Objective
This study was undertaken to evaluate the risks and benefits of single-layer uterine closure at cesarean delivery on the index and subsequent pregnancy.
Study design
A retrospective study of women delivered of their first live-born infants by primary low transverse cesarean delivery (1989-2001) and their subsequent pregnancy at our institution was performed.
Criteria for inclusion
- women whose first baby was born by c-section and had a low transverse incision
Criteria for exclusion
- upper uterine segment extension or T-incision
- prior uterine mymetrial sugery
- women who delivered either pregnancy before 24 weeks gestation
Study size: N = 768
Single layer = 267
Double layer = 501
DEFINITIONS
Uterine rupture: a full-thickness defect through myometrium and peritoneum
Single layer suture: 1 continuous running suture applied to the lower uterine segment with additional interrupted hemostratic sutures placed as needed
Double layer suture: second continuous imbricating layer applied over the first layer
Uterine Window: asymptomatic uterine defect with intact overlying peritoneum
Uterine closure: 99.2% were done with polyglactin 910 suture (0-Vicryl)
Blood loss
Single layer = 646 mL
Double layer = 690mL
p<.01
Trial of labor
single layer: 182/267 (68.2%)
double layer: 340/501 (67.9%)
VBAC success (out of the Trial of Labor group)
single layer: 124/182 (68.1%)
double layer: 220/340 (64.7%)
Operative time
Single layer = 46 min
Double layer = 52 min
P<.001
Endometriosis
Single layer = 13.5%
Double layer = 25.5%
P<.001
Postoperative stay
Single layer = 3.5 days
Double layer = 4.1 days
P<.001
Induction*
single layer: 38/182 (20.9%)
double layer: 55/340 (16.2%)
* None of the 4 UR in the study were associated with prostaglandin use
Oxytocin (pitocin) use:
single layer: 111/182 (61.0%)
double layer: 186/340 (54.7%)
Uterine rupture
Single layer = 0 total (0%)
Double layer = 4 total (0.8% of all women in the study with a double layer; 1.2% of those who went through a Trial of Labor)
P=.30
Uterine windows (at subsequent cesarean delivery)
Single layer = 3.5%
Double layer 0.7%
P=.046
Conclusion
Single-layer uterine closure is associated with decreased infectious morbidity in the index surgery, but not uterine rupture or other adverse outcomes in the subsequent gestation.
From the Department of Obstetrics and Gynecology, MetroHealth Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
NOTES
- There were NO UR in the single layer group in this study! 4 UR in the double layer group
- Neither group had placenta accreta nor maternal death
- No cesarean hysterectomies were required
- Study was done at the same hospital instead of gathering data from more than 1 hospital
- Significant reduction in endometriosis and postioperative stay
- Findings were consistent with the Chapman et al study (1997) and the Tucker et al study (1993)
- None of the 4 UR in the study were associated with prostaglandin use
- Major difference between this study and the Bujold et al study (2002) was the type and technique for uterine suture (The Bujold study detected a 4 fold increase in the rate of UR in single layer sutures). This study used polyglactin 910 (0-Vicryl) in a continuous unlocked closure. Bujold et al used a chromic catgut suture in a continuous locked stitch.
- chromic catgut is degraded by proteolytic enzymes and loses half of its tensile strength within 7-10 days; Polyglactin (0-Vicryl) is degraded by hydolysis and maintains all of its tensile strength for at least 7 -10 days.
- It is plausible that a running locked closure leads to vascular occlusion and poorer wound healing
- Mean interdelivery interval with the UR was 2.6 years (only 1 UR case had less than 2 years between deliveries)
- No uterine windows/dehiscences were detected in women who had successful vbacs but only 31% had their uteruses palpated and they may not have been detected anyway
- To adequately evaluate a 2 fold increased risk of UR after single-layer closure from a 1.2% wiht double layer closure with 80% power, they would have needed 3848 women
STUDY 2 - I reviewed the full study
Impact of single layer or double layer closure on uterine rupture in subsequent labour
Shahid Irshad Rao, Bushra Faiz, Saqib Ramzan,
Nishtar Hospital and Medical College, Multan
http://www.pmrc.org.pk/uterine.htm
Pakistan J. Med. Res
Vol 42 No.1, 2003
Objectives: The purpose of this study was to assess the impact of single layer or double layer closure on uterine rupture at subsequent delivery.
METHODS:
Total number of women in the study undergoing trial of labor (TOL): N= 1041
Criteria for inclusion
- one previous transverse lower segment caesarean section and going for trial of labour
- had operative details of previous caesarean delivery.
- spontaneous onset of labour and none had induced labour.
Type of closure
Single closure 457/1041 (43.9)
Double closure 584/1041 (56.1)
VBAC: 802/1041 (77.04%)
Repeat c-section after TOL: 225 (21.6%)
Outcome of Labor
Single layer closure (n=457)
- Vbac: 336/457 (73.5%)
- uterine rupture: 6/457 (1.3%) NOTE: chromic catgut suture was used in 4 cases ; polyglycolic acid (Vicryl-type) suture was used in 2 cases
- c-section: 115/457 (25.2%)
- uterine dehiscence: 9/115 (7.8%)
Double layer closure (n=584)
- Vbac: 466/584 (79.8%)
uterine rupture: 8/584 (1.4%)
- c-section: 110/584 (18.8%)
uterine dehiscence: 10/110 (9.1%)
Uterine Rupture: 14/1041 (1.34%)
single layer: 6/647 (1.3%)
double layer: 8/584 (1.4%)
Conclusion: Single layer uterine closure with polyglycolic acid suture gives as strength to uterine scar as double uterine closure. In addition there is short operative time and less postoperative morbidity observed in single layer closure.
NOTES
- no induction/augmentation
- UR rates are still higher than recent averages.
- chromic catgut used in most UR cases (which is the suturing they used in the negative articles!!)
-suturing in double layer UR cases not stated.
STUDY 3 - I reviewed the FULL STUDY
One- versus two- layer closure of a low transverse cesarean: the next pregnancy
Authors: SJ Chapman, J Owen, and JC Hauth
Obstetrics & Gynecology 1997;89:16-18
© 1997 by The American College of Obstetricians and Gynecologists
Study size: N=164
Single layer suture = 83
Double layer suture = 81
ERCS group = 19/164 (12%)
TOL group = 145/164 (88%)
UTERINE CLOSURE in TOL group
single layer: 70/145 (48.3%)
double layer: 75/145 (51.8%)
OXYTOCIN (PITOCIN) USE
85/145 women undergoing TOL (study does not specify percentages in each group)
UTERINE DEHISCENCE
single layer: 1/70 (1.4%)
double layer: 0/75 (0%)
VBAC success
single layer group: 56/70 (80%)
double layer group: 64/75 (85.3%)
Uterine Rupture: 0% overall
single layer: 0/70
double layer: 0/75
Perinatal death
single layer: 2 (one stillbirth and 1 from extreme prematurity)
double layer: 3 (2 still births and 1 from extreme prematurity
Length of labor, mode of delivery, duration of hospital stay, gestation at delivery, and the incidences of uterine scar dehiscence, chorioamnionitis, postpartum metritis, hemorrhage, transfusion, and abnormal placentation did not differ significantly between the groups. Selected neonatal outcomes, including Apgar scores, cord pH, birth weight, and perinatal death, were similar between groups as well.
CONCLUSIONS: These findings suggest that the type of low transverse cesarean closure does not significantly affect the outcome of the next pregnancy.
NOTES:
- 1-0 chromic catgut used to suture all women
- There were NO uterine ruptures in either group
- study included twin gestations in TOL group (3 in single layer group and 3 in double layer group)
- small sample size limits statistical power
STUDY 4 - I reviewed the abstract only
[Does the suture material and technique have an effect on healing of the uterotomy in cesarean section?]
[Article in Croatian]
SestanoviÄ Z, Mimica M, VuliÄ M, Roje D, TomiÄ S.
Klinika za zenske bolesti i porode KB Split.
OBJECTIVE: To present the influence of different suturing techniques and different materials (catgut plain, Dexon and Vicryl) on healing of lower transverse uterotomy (in further text uterotomy) in Cesarean section (CS).
Uterotomies were sutured by four ways:
Single layer sutures:
Group A: one row interrupted (non-locking)
Group B: one row continuous (locking)
Double layer sutures
Group C: two rows interrupted
Group D: two rows interrupted and continuous
7830 women reviewed in study; 1946 (24.8%) had repeat deliveries and were included in the results (n=1946)
ERCS = 887 (45.0%)
Vbacs = 1059 (55.0%)
There were 15 (0.8%) uterine-rupture dehisences (URD) out of 1946 deliveries
Catgut group (n=302)
11 (3.6%) URD
9 (7.2%) in Group D (n=125)
2 (1.7%) in Group C (n= 20)
0 in Group A (n=57)
Dexon Group (n= 226)
No URD diagnosed
Vicryl Group (n=1486)
4 (0.28%) URD{
- 1 (0.16%) in Group A (n=615)
- 1 (0.3%) in Group B (n=333)
- 1 (0.52%) in Group C (n=190)
- 1 (0.35%) in Group D (n280)
Uterine Rupture overall:
single layer: 2/948 (0.2%) --> both were Vicryl sutures
double layer: 13/615 (2.1%) --> 11 of these used catgut sutures
CONCLUSIONS: The best uterine scar is the one after using one layer interrupted Vicryl and Dexon suture. The worst healing results were obtained after two-row interrupted and continuous sutures using catgut.
NOTES
- induction/augmentation unknown
PMID: 15038214 [PubMed - indexed for MEDLINE]
STUDY 5 - I reviewed the full study
Trial of Labor after a one- or two- layer closure of a low transverse uterine incision
authors: J. Martin Tucker, MD, John C. Hauth, MD, Pam Hodgkins, RN, John Owen, MD, and Carey L. WInkler, MD
Birmingham, AL
Am J of Obstet Gynecol, Feb 1993: 545-546
OBJECTIVE: A retrospective review to evaluate the safey of a trial of labor after a one-layer closure of a low transverse uterine incicion
Inclusion
- only women who underwent a low transverse cesarean section without vertical extension
UTERINE CLOSURE
single layer: 149 women
defined as one continous layer of locking No. 1 chomic catgut suture
double layer: 143 women
defined as 2 continous layers with the first one locked
Uterine Rupture
single layer: 0/149
double layer: 0/143
Uterine scar separation (asymptomatic)*
single layer: 3/149 (2.1%)
double layer: 5/143 (3.5%)
* this may have been higher due to lack of documentation in operative and delivery summaries
CONCLUSION: These data support the premise that a trial of labor should not be altered by whether the patient had a prior one- or two- layer closure of the low transverse cesarean scar.
NOTES
- Very small sample size (n= 292 women)
- No uterine ruptures in either single or double layer group
- No information given on other UR risk such as induction, augmentation, time interval between deliveries and maternal age.
- This appears to be the first study to look at the effect of single vs double layer suturing.
- Study only included women in 1 hospital.
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