Barbed Suture: A Look at Its Use for Hysterotomy Closure During Cesarean Section
Phase: NA
Conditions: Hysterotomy
Sponsor: Icahn School of Medicine at Mount Sinai

Barbed Suture: A Look at Its Use for Hysterotomy Closure During Cesarean Section  
NCT04622267
PI: Calvin Lambert
Document Date: 8-6-2024

Protocol 
Title: Barbed Suture: A Look at its Use for Hysterotomy Closure During Cesarean Sections
Principal Investigator: Calvin Lambert, MD
Institution: Icahn School of Medicine at Mount Sinai Hospital
Background: Surgical knot tying is a central part of any procedure and a crucial part of surgical 
technique. However, while it is a means of tissue approximation, more importantly, knot tying plays a 
role in anchoring the suture to the tissue. Knot tying also introduces human error and interuser 
variability given the innate differences in ability to tie a secure knot (1). Barbed suture has pioneered the 
way for knot-less surgical technique, thereby decreasing some of the human error associated with the 
process of tying a knot. Bidirectional barbed suture incorporates tiny barbs that distribute the tension 
along the entire suture line rather than the knotted ends as seen with traditional suture material (2).  
With barbed suture, no knots are required. There have been several studies looking at the use of barbed 
suture in gynecology and it is already in wide use in the field of minimally invasive gynecological surgery, 
however very few studies have looked at the use in obstetrics. Currently cesarean sections are the most 
common procedure performed in the United States (6) and at our institution we perform over 8,000 
deliveries per year. The objective of this study is to investigate whether barbed suture conveys a 
decrease in quantitative blood loss when compared to conventional suture. 
General Design: This is a prospective, randomized controlled trial evaluating whether using a barbed 
suture to close a C-section incision can reduce blood loss.  Patients undergoing C-section will be 
randomized with equal allocation to a barbed suture or a standard antimicrobial suture.  The primary 
outcome is quantification of blood loss (QBL). At Mount Sinai Hospital, QBL is calculated by Triton AI 
which captures sponge and canister images to accurately monitor blood loss in real time. Differences 
between the groups will be assessed using a 0.05 level Wilcoxon rank-sum test.  Secondary outcomes 
include time for hysterotomy closure, need for additional hemostatic sutures, rate of endometritis/SSI 
(superficial wound infection, deep wound infection, and endometritis) within 6 weeks postpartum, use 
of hemostatic agents, and differences in pain which will be assessed by a telephone screening in the 
days following delivery. The Mann-Whitney test will be used to compare continuous outcomes between 
the barbed suture and antimicrobial suture groups. Continuous secondary outcomes include time for 
hysterotomy closure (in minutes), and difference in pain between post-surgery day 1 and day 14. The 
Chi-square test of Fisher’s exact test (as appropriate) will be used to compare the incidence rate of 
binary outcomes between the two patient groups. Binary secondary outcomes include need for 
additional hemostatic sutures (Y/N), endometritis or surgical site infection (SSI) within 6 weeks of 
surgery (Y/N), and use of hemostatic agents (Y/N). Inclusion criteria (1) those undergoing an elective 
scheduled cesarean delivery at ≥ 37 weeks’ gestation, (2) those in labor requiring cesarean delivery for usual 
obstetrical indications, or (3) those who failed a trial of labor after a previous cesarean delivery at Mount Sinai 
Hospital ages 18-64. Exclusion criteria include, multifetal gestations, placenta previas, and patients with a known 
coagulopathy (DIC, Von Willebrands Disease, etc). Also excluded are patients with IAI, patients on magnesium 
sulfate, placenta abruption, and PAS.
Sample Size: Sample size is based on a two-sided, equal variance T-test.  Since the distribution of QBL is 
non-normal, the calculation was inflated by 15% to ensure adequate power for the nonparametric 
Wilcoxon rank-sum test as recommended by Lehmann (5).  Based on data from C-section patients seen 
at Mount Sinai from 2018-2019, the distribution of QBL is assumed to have a mean of 534 and a 
standard deviation of 371.  (Figure 1).
Figure 1. Distribution of QBL in C-Section Patients at Mount Sinai from 2018-2019
Effective Date: 8/6/2024
End Date:8/5/2025

Assuming each group has a standard deviation of 371 and the control group has a mean QBL of 534, a 
sample size of 226 patients (113 in each group) provides ~85% power to detect a 30% decrease in mean 
QBL between the groups at the 0.05 significance level.  Sample size for alternative effect sizes are tabled 
below. 300 sutures are requested by the investigators to standardize a double layer closure for all 
patients as is the standard of care for most Obstetricians (113 patients in the barbed suture arm, double 
layer would require 226 suture, we are requesting 452 suture so extra suture is available should 
additional hemostatic sutures be needed. 
Power
Alpha
Mean QBL 
in Control 
Group
Mean QBL in 
Experimental 
Group
Standard 
Deviation in 
Both 
Groups
Absolute 
Difference 
of Means
Relative 
Difference 
of Means
Group N
Total N
0.85
0.05
534
267
371
267
50%
42
84
0.85
0.05
534
320.4
371
213.6
40%
65
130
0.85
0.05
534
373.8
371
160.2
30%
113
226
0.85
0.05
534
427.2
371
106.8
20%
251
502
Effective Date: 8/6/2024
End Date:8/5/2025

Provisions to decrease risk
This study is greater than minimal risk, however there are no reasonably foreseeable risks to 
the subjects and no inconvenience as they are recruited/screened/consented during their 
routine prenatal care. The barbed suture is not being used outside of its scope of use. There is 
always a risk of breach of confidentiality. 
Patients will be recruited by their obstetrical provider. To mitigate the risk of breach of 
confidentiality and ensure confidentiality, the following system will be adhered to: when 
subjects are enrolled in this study, they will be assigned a unique identification code. 
Corresponding medical record numbers for each code (keycode will be stored in a password 
locked documentation the MFM servers that can be accessed only by members of the research 
team. At the conclusion of the data extraction, the outcome variable will be assessed and the 
key codes to the medical record number will no longer be necessary, and that information will 
be permanently erased from the key code file. Electronic data with identifiers will be encrypted 
according to Data Security Standards.
Benefits 
There is no direct benefit.
The benefit to society is that since barbed suture is successfully and routinely used in 
gynecological surgery, establishing its use in obstetrical surgery could demonstrate 
improvements in patient care in the form of shorter operative times, more secure tissue 
approximation without the introduced interuser variability due to knot tying, and decreased 
risk of infection and pain. As cesarean sections are the most common procedure being 
performed in the U.S, any advances in surgical technique would prove extremely useful.
Risk/benefit assessment
This research involves less than minimal risk. To mitigate the risk of breach of confidentiality 
and ensure confidentiality, the following system will be adhered to: when subjects are enrolled 
in this study, they will be assigned a unique identification code. Corresponding medical record 
numbers for each code (keycode will be stored in a password locked documentation the MFM 
servers that can be accessed only by members of the research team. At the conclusion of the 
data extraction, the outcome variable will be assessed and the key codes to the medical record 
number will no longer be necessary, and that information will be permanently erased from the 
key code file. Electronic data with identifiers will be encrypted according to Data Security 
Standards.
Data analysis will be performed at the halfway mark to ensure there is no inadvertent harm to 
the subjects. Additionally, the barbed suture will be used in the capacity of its labeled use. 
Therefore the potential risk to the subject is low. There is no risk to the fetus as it will be 
delivered prior to the intervention
There is no direct benefit.
Effective Date: 8/6/2024
End Date:8/5/2025

Scientific rationale for study designer
This study is extremely feasible given 1/3 of all 8,000 deliveries performed at Mount Sinai are 
cesarean sections.
This is a prospective, randomized controlled trial evaluating whether using a barbed suture to 
close a C-section incision can reduce blood loss. Patients undergoing C-section will be 
randomized with equal allocation to a barbed suture or a standard antimicrobial suture. The 
primary outcome is quantification of blood loss (QBL). Differences between the groups will be 
assessed using a 0.05 level Wilcoxon rank-sum test. Secondary outcomes include time for 
hysterotomy closure, need for additional hemostatic sutures, rate of endometritis, use of 
hemostatic agents, and differences in pain which will be assessed by a telephone screening 2 
weeks following delivery. The patients will be contacted by study personnel 2 weeks after 
delivery(they will be instructed on this upon discharge) to discuss pain control, bowel or 
bladder complaints, and amount of narcotic use necessitated post-operatively. Demographic 
information will be obtained from the electronic medical record.
Recruitment process
Participants will be identified by their obstetrical provider and research staff as meeting 
inclusion criteria. The research will be introduced to the patient by their treating physician. 
Only upon expressed interest will the subject be approached for consent by the study team. 
The research personnel will be notified by the patient's treating physician of the subject's 
interest and the research personnel will then obtain official written consent.
Alternatively, to minimize in-person interaction during the COVID pandemic, research staff will 
identify the patients who are eligible for the study by reviewing the sonography schedule for 
patients having a nuchal translucency appointment at the correct gestational age, and then 
reviewing pregnancy history to identify patients who also have had a previous cesarean 
delivery. A HIPAA Waiver of Authorization has been attached to this submission. We will send a 
MyChart message/email to those patients (attached) regarding the research study, with 
patients being able to opt-out of the study at this time. We will then send a copy of the consent 
form via email (secured RedCap link). They will have the opportunity to review the consent 
form before we call. Next, we will contact them via phone or Mount Sinai Zoom account to 
review the consent form and answer any questions from them. This will be documented in 
EPIC. They can then sign it electronically if they agree to participate. Their participation in the 
study will be documented in their chart via FYI and their consent form will be scanned and 
uploaded into media within EPIC.
The research will be introduced to the participants by the patient’s obstetrical provider. The 
obstetrical provider and research team will assess the patient's eligibility for the study and 
discuss if applicable. A consent form which details the goals and objectives of the study as well 
as the suture materials will be provided by the provider. Patients will be given the material to 
read on their own and if interested in participating, a research personnel will obtain formal 
Effective Date: 8/6/2024
End Date:8/5/2025

written consent and answer any questions. The provider will assess if the patient meets 
inclusion and exclusion criteria for participation.
Participants will undergo a medical and surgical screening prior to enrollment by their 
obstetrical provider. There will be no cold contacts with patients.
Consent process
The patients will be given the study information by their obstetrical provider in the third 
trimester once patient has been identified as meeting the inclusion criteria. If interested, the 
obstetrical provider will notify study personnel and personnel will obtain written consent at 
subsequent visits (i.e when presenting for pre-operative labs at the Martha Stewart 
Laboratory). Alternatively, patients will provide informed consent online and over phone/zoom 
to facilitate consent process while maintaining social distancing.
Product storage and preparation
The device will be stored in the locked office of one of the research personnel and will only be 
handles by the research team until randomization is performed and the patient is allocated to 
the treatment arm. Only at that time would the research personnel go into the locked office 
and obtain the suture material for the subject. The material would be then handed off with 
sterility to the scrub tech who would provide the suture to the surgeon during the procedure
Safety assessments
This research involves less than minimal risk. To mitigate the risk of breach of confidentiality 
and ensure confidentiality, the following system will be adhered to: when subjects are enrolled 
in this study, they will be assigned a unique identification code. Corresponding medical record 
numbers for each code (keycode will be stored in a password locked documentation the MFM 
servers that can be accessed only by members of the research team. At the conclusion of the 
data extraction, the outcome variable will be assessed and the key codes to the medical record 
number will no longer be necessary and that information will be permanently erased from the 
key code file. Electronic data with identifiers will be encrypted according to Data Security 
Standards.
Data handling and storage
When subjects are enrolled in this study, they will be assigned a unique anonymized 
identification code. All data will be entered and coded using this key-code into REDCap, a 
password protected and HIPAA compliant database. Corresponding medical record numbers for 
each code (key-code) will be stored in a password locked document on the MFM server that 
can be accessed only by members of the research team. At the conclusion of the data 
extraction, the outcome variable will be assessed and the key codes to the medical record 
numbers will no longer be necessary, and that information will be permanently erased from the 
key-code file per PPHS guidelines.
Effective Date: 8/6/2024
End Date:8/5/2025

References:
1)
Greenberg, J. A., & Goldman, R. H. (2013). Barbed suture: a review of the technology and clinical 
uses in obstetrics and gynecology. Reviews in obstetrics & gynecology, 6(3-4), 107–115.
2)
Greenberg JA, Einarsson JI. Bidirectional barbed suture for laparoscopic myomectomy. J Minim 
Invasive Gynecol. 2008;15(suppl):S11.
3)
Mohamed A. Zayed, Usama M. Fouda, Khaled A. Elsetohy, Shereef M. Zayed, Ahmed T. Hashem 
& Mohamed A. Youssef (2019) Barbed sutures versus conventional sutures for uterine closure at 
cesarean section; a randomized controlled trial, The Journal of Maternal-Fetal & Neonatal 
Medicine, 32:5, 710-717, DOI: 10.1080/14767058.2017.1388368
4)
Peleg D, Said Ahmad R, Warsof SL, et al. A randomized clinical trial of knotless barbed suture vs 
conventional suture for closure of the uterine incision at cesarean delivery. Am J Obstet Gynecol 
2018;218:343.e1-7.
5)
Erich L. Lehmann, Nonparametrics: Statistical Methods Based on Ranks, Revised, 1998, pages 
76-81.
6)
Pfuntner A, Wier LM, Stocks C. Most Frequent Procedures Performed in U.S. Hospitals, 2010: 
Statistical Brief #149. 2013 Feb. In: Healthcare Cost and Utilization Project (HCUP) Statistical 
Briefs [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2006 
Feb. Available from: https://www.ncbi.nlm.nih.gov/books/NBK132428/
Effective Date: 8/6/2024
End Date:8/5/2025