Alexis O-Ring Wound Retractor for the Prevention of Post-cesarean Surgical Site Infections (Alexis)

Alexis O-Ring Wound Retractor for the Prevention of Post-cesarean Surgical Site Infections: A Randomized Controlled Trial

Post cesarean section surgical site infection (SSI) is a common complication that can affect patient recovery and overall outcome. Several approaches have been studied to improve SSI rates such as timing of antibiotic administration and skin preparation. Alexis retractors have been suggested as a reasonable option to decrease SSI. However, to date there is only one randomized controlled study assessing its efficacy. The aim of this study is to whether Alexis wound retractors are beneficial in preventing cesarean section SSI.

Study Overview

• Status: Completed
• Conditions: Surgical Wound Infection
• Intervention / Treatment: Device: Alexis O-Ring Wound Retractor; Other: Standard Surgical Retractors

Detailed Description

The study design was a randomized controlled study to evaluate wound infection rates in patients undergoing a cesarean delivery. The patients were randomized into two sub- groups; the first group received routine hand-held metal retractors as needed by the surgical team, and the second group received an Alexis Wound Retractor. Inclusion criteria included: maternal age of at least 18 years, a gestational age of at least 24 0/7 wks by best obstetric estimate, a viable gestation, a non-emergent cesarean delivery, and a planned transverse skin incision. Deliveries included: primary cesarean for failed induction, maternal request, or other obstetric indications; and repeat cesarean deliveries that were elective or had obstetric indications (such as spontaneous labor in a subject with a term gestation and with history of 2 or more prior cesarean deliveries). Exclusion criteria included chorioamnionitis, chronic corticosteroid therapy, a prior abdominal vertical skin incision scar or planned vertical incision, history of a prior wound infection or separation, a planned cesarean hysterectomy, or maternal or fetal complications requiring an emergent delivery.

Randomization was done using a web-based randomization generator. Variables were allocated as: 1 for Alexis, and 0 for conventional surgical retractors. Packages including consent forms, data sheets, and the randomized allocation were prepared for the entire study and were stored in one office. Study packets were prepared to include a sealed envelope indicating randomization to be opened after the consent form was signed. Only after randomization, the Alexis retractor was opened and placed on the surgical field.

Prior to initiation of the study, in-service sessions were conducted with OB surgical teams to facilitate the use of the retractors. Information provided included optimal use of the retractor and selection of the appropriate retractor size. The primary surgeon of each case was previously trained by the principle investigator in placement of the retractor on actual patients.

Once a decision was made to proceed with cesarean delivery, the subject was approached and offered to participate in the study. After the patient had been enrolled and consent forms signed, an allocated envelope for each study subject determined which arm of the study to which the patient would be randomized; no other management decisions was made as part of the RCT. Surgical decisions were independent of the patient's designated study arm and retractor type. Such decisions included: type of anesthesia, length of transverse skin incision , method of tissue dissection (blunt vs. instrumental), creation of bladder flap, size and nature of uterine incision (transverse, low vertical, classical, J-type, T-incision), surgical material used, exteriorization of the uterus, manual vs. spontaneous delivery of placenta, layer closure techniques (bladder flap, peritoneum, subcutaneous tissue), and skin closure technique (staples, subcuticular sutures). Skin preoperative preparation was performed as standard with ChloraPrep® Applicator (2% Chlorhexidine gluconate and 70% isopropyl alcohol). Intravenous antibiotics were given preoperatively in accordance to national guidelines (12). The primary outcome of this study was the development of a surgical site infection after cesarean delivery within two weeks after cesarean.

Incisions were checked daily in-house. However, the exams that were used in this study to determine the occurrences of SSI were the first exam done in the outpatient setting for removal of staples (post op days 5 - 7), and the two week post partum visit (post op days 14 - 18). SSIs were diagnosed according to the Centers for Disease Control and Prevention (CDC) criteria.(13). The most commonly seen characteristics were purulent drainage or localized swelling and/or redness of the surgical wound.

In addition, other wound complications were also assessed and included: seroma (wounds with clear drainage) and/or hematomas. Other secondary outcomes included skin time to uterine incision (minutes) , exteriorization of the uterus(yes, no), total operative time (minutes), estimated blood loss (mL) estimated by the primary surgeon, and postoperative pain based on a subjective 1-10 pain scale, assessed 4 times daily while hospitalized and at the outpatient visits previously mentioned.

An initial sample size estimate was performed using the frequentist approach with an assumption of power 80% and Type 1 error = 5% (2-sided). The primary outcome of the study is expected to occur in 15% of women in the "usual care" group. In order to detect a 50% reduction (15% to 7.5%) in the rate of wound complications with the use of the Alexis retractor, a total sample size of 564 women will be needed (282 per group). The planned study was to be carried out at two distinct sites: the University of Texas Medical Branch in Galveston (UTMB) and the University of Texas in Houston. The Institutional Review Board of UTMB-Galveston IRB # 10-188 approved the study.

• Study Type: Interventional
• Enrollment (Actual): 564
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• maternal age of at least 18 years
• a gestational age of at least 24 0/7 wks by best obstetric estimate
• a viable gestation
• a non-emergent cesarean delivery
• a planned transverse skin incision
• Deliveries included: primary cesarean for failed induction, maternal request, or other obstetric indications; and repeat cesarean deliveries that were elective or had obstetric indications (such as spontaneous labor in a subject with a term gestation and with history of 2 or more prior cesarean deliveries)

Exclusion Criteria:

• chorioamnionitis
• chronic corticosteroid therapy
• prior abdominal vertical skin incision scar or planned vertical incision
• history of a prior wound infection or separation
• planned cesarean hysterectomy
• maternal or fetal complications requiring an emergent delivery

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Alexis Retractor; This group received an Alexis O-Ring Wound Retractor during cesarean delivery.	Device: Alexis O-Ring Wound Retractor; A flexible self-retaining plastic Alexis retractor was used in place of standard surgical retractors.
Active Comparator: Standard Surgical Retractors; This group received routine hand-held metal retractors as needed by the surgical team during cesarean delivery.	Other: Standard Surgical Retractors; Routine hand-held metal retractors as needed by the surgical team

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surgical Site Infection	Assessed as present or absent. Defined as the development of wound infection, seroma, or other wound disruption in patients who underwent a cesarean delivery	Time of surgery up to 14 post operative days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative pain	Patients are asked to report pain on a scale of 1-10, 1 no pain and 10 the worst pain.	Time of surgery up to 14 post operative days
Estimated blood loss	Defined as the amount of blood loss during the cesarean delivery as estimated by the operating surgeons.	intraoperative assessment
Uterus exteriorization	Quantified as yes or no; defined as whether or not the surgeons' exteriorized the uterus extra-corporally (removed from abdominal cavity) at any time of the cesarean delivery	intraoperative assessment
Total operative time	Defined as the total length of time in minutes required to perform the cesarean delivery from time of initial skin incision to completion of skin closure.	intraoperative assessment

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Apgar scores	Score given by pediatrician or pediatric provider to each infant at 1 and 5 minutes of life	Assessed in every infant at 1 minute and 5 minutes of life
Gestational age at time of delivery	Completed gestational age in weeks	at time of delivery
Infant weight	Infant Weight in kg	At time of delivery
Type of gestation	Singleton or multiple fetus	Noted at the time of delivery
Maternal hypertension	Systolic blood pressure greater than 140 and diastolic blood pressure greater than 90 mmHG	At the time of delivery until 14 days after delivery

Collaborators and Investigators

• Sponsor: The University of Texas Medical Branch, Galveston
• Investigators: Principal Investigator: Gayle L Olson, MD, University of Texas Medical Branch in Galveston; Study Chair: George Saade, MD, University of Texas Medical Branch in Galveston

Publications and helpful links

General Publications

• Stone PW, Braccia D, Larson E. Systematic review of economic analyses of health care-associated infections. Am J Infect Control. 2005 Nov;33(9):501-9. doi: 10.1016/j.ajic.2005.04.246.
• Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for Prevention of Surgical Site Infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control. 1999 Apr;27(2):97-132; quiz 133-4; discussion 96.
• Kirkland KB, Briggs JP, Trivette SL, Wilkinson WE, Sexton DJ. The impact of surgical-site infections in the 1990s: attributable mortality, excess length of hospitalization, and extra costs. Infect Control Hosp Epidemiol. 1999 Nov;20(11):725-30. doi: 10.1086/501572.
• ACOG Practice Bulletin No. 120: Use of prophylactic antibiotics in labor and delivery. Obstet Gynecol. 2011 Jun;117(6):1472-1483. doi: 10.1097/AOG.0b013e3182238c31. No abstract available.
• Menacker F, Hamilton BE. Recent trends in cesarean delivery in the United States. NCHS Data Brief. 2010 Mar;(35):1-8.
• Moir-Bussy B, Hutton R, Thompson J. Wound infection after caesarean section. Nurs Times. 1985 Jun 5-11;81(23):suppl 13-4. No abstract available.
• Rauk PN. Educational intervention, revised instrument sterilization methods, and comprehensive preoperative skin preparation protocol reduce cesarean section surgical site infections. Am J Infect Control. 2010 May;38(4):319-23. doi: 10.1016/j.ajic.2009.10.004. Epub 2010 Feb 19.
• Schneid-Kofman N, Sheiner E, Levy A, Holcberg G. Risk factors for wound infection following cesarean deliveries. Int J Gynaecol Obstet. 2005 Jul;90(1):10-5. doi: 10.1016/j.ijgo.2005.03.020.
• Tran TS, Jamulitrat S, Chongsuvivatwong V, Geater A. Risk factors for postcesarean surgical site infection. Obstet Gynecol. 2000 Mar;95(3):367-71. doi: 10.1016/s0029-7844(99)00540-2.
• Weiss JL, Malone FD, Emig D, Ball RH, Nyberg DA, Comstock CH, Saade G, Eddleman K, Carter SM, Craigo SD, Carr SR, D'Alton ME; FASTER Research Consortium. Obesity, obstetric complications and cesarean delivery rate--a population-based screening study. Am J Obstet Gynecol. 2004 Apr;190(4):1091-7. doi: 10.1016/j.ajog.2003.09.058.
• Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol. 2004 Feb;103(2):219-24. doi: 10.1097/01.AOG.0000107291.46159.00.
• Cheng KP, Roslani AC, Sehha N, Kueh JH, Law CW, Chong HY, Arumugam K. ALEXIS O-Ring wound retractor vs conventional wound protection for the prevention of surgical site infections in colorectal resections(1). Colorectal Dis. 2012 Jun;14(6):e346-51. doi: 10.1111/j.1463-1318.2012.02943.x.

Helpful Links

• NHS Information Centre. HES online: maternity data

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2010
• Primary Completion (Actual): October 1, 2013
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: June 9, 2015
• First Submitted That Met QC Criteria: December 1, 2017
• First Posted (Actual): December 7, 2017

Study Record Updates

• Last Update Posted (Actual): October 19, 2018
• Last Update Submitted That Met QC Criteria: October 17, 2018
• Last Verified: May 1, 2018

More Information

Terms related to this study

• Keywords: Surgical Site Infection; Cesarean delivery infection
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Disease Attributes; Infections; Communicable Diseases; Wounds and Injuries; Surgical Wound; Surgical Wound Infection; Wound Infection
• Other Study ID Numbers: 10-188

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No