Title:
Efficacy of Hypochlorous Acid (HOCl) Peritoneal Lavage in Reducing Surgical Site Infections Following Oncologic Laparotomy: A Randomized Controlled Pilot Study

Background:
Surgical site infections (SSIs) remain a significant source of postoperative morbidity and increased healthcare costs in oncologic laparotomy, particularly among patients undergoing gastrointestinal and gynecologic cancer surgeries. Despite adherence to perioperative antibiotic prophylaxis and strict aseptic techniques, the reported incidence of SSIs in this population ranges from 15 to 25 percent. These infections can delay recovery, prolong hospital stay, and potentially compromise oncologic outcomes.

Hypochlorous acid (HOCl) is a naturally occurring antimicrobial compound produced by neutrophils during the respiratory burst. It exhibits potent, broad-spectrum activity against Gram-positive and Gram-negative bacteria, viruses, and fungi, with minimal cytotoxicity to human cells at therapeutic concentrations. Due to its rapid action and excellent tissue compatibility, HOCl has gained increasing attention for use in wound irrigation, topical antisepsis, and biofilm disruption.

Recent studies suggest that intraoperative peritoneal lavage with HOCl may reduce microbial contamination within the surgical field, thereby potentially lowering the risk of SSIs. Compared with saline or conventional antiseptics such as povidone-iodine and chlorhexidine, HOCl demonstrates superior microbial clearance without the adverse tissue reactions associated with those agents.

Given its favorable safety profile and promising antimicrobial properties, this study aims to evaluate the efficacy of HOCl-based peritoneal lavage in reducing SSIs following oncologic laparotomy through a randomized controlled pilot design.

Objectives:

Primary Objective:
To compare the incidence of SSIs within 30 days postoperatively between patients receiving hypochlorous acid peritoneal lavage and those receiving normal saline lavage.

Secondary Objectives:
To assess the severity (superficial, deep, organ or space) and time to onset of SSIs.
To compare postoperative inflammatory markers (CRP, WBC count) between groups.
To evaluate the length of hospital stay and readmission rates.
To assess safety and adverse events related to HOCl use.

Methodology:

Study Design: Randomized controlled double-blind pilot study.
Data Collection Type: Prospective.
Total Duration of Study: 12 months (9 months recruitment and 3 months follow-up and analysis).
Sample Size: 60 patients (30 per arm), powered to detect a 50 percent reduction in SSI rate from 20 percent to 10 percent with 80 percent power and alpha = 0.05.

Subjects:

Inclusion Criteria:
Adults aged 18 to 75 years undergoing elective oncologic laparotomy.
ECOG performance status 0 to 2.
Ability to provide informed consent.

Exclusion Criteria:
Immunocompromised state (for example, neutropenia, HIV).
Perforation or gross fecal contamination at the time of surgery.

Materials and Study Setting:
The study will be conducted in the Departments of Surgical Oncology and Gynecologic Oncology at Aster Hospital, Whitefield, a tertiary care referral center with a dedicated oncology program. All clinical care, surgical interventions, follow-up assessments, and data collection will occur at this single site. Participants will be recruited from inpatients scheduled for elective oncologic laparotomy involving gastrointestinal and gynecologic malignancies. Eligible patients will be screened during the preoperative evaluation by the surgical team.

Randomization and Allocation:
Participants will be randomized 1:1 using a computer-generated block randomization protocol (block size 4 or 6).
Group A (Intervention arm): Intraoperative peritoneal lavage with 500 mL of stabilized hypochlorous acid solution after tumor resection and hemostasis.
Group B (Control arm): Intraoperative peritoneal lavage with 500 mL of sterile normal saline.
Randomization will be implemented using opaque sealed envelopes to ensure allocation concealment.

Blinding:
The study will be double-blind. Both patients and outcome assessors will be blinded to group allocation.

Surgical Technique and Procedure:
All procedures will be performed via midline laparotomy under general anesthesia by experienced surgical oncologists. Standard oncologic resection principles will be followed. After achieving hemostasis, the peritoneal cavity will be irrigated with the assigned solution as follows: instillation of 500 mL of HOCl or saline, dwell time of 2 minutes, and complete suctioning of the fluid prior to closure. Skin preparation and wound closure will be standardized using chlorhexidine prep, absorbable subcutaneous sutures, and either staples or subcuticular skin closure. A closed-suction drain (for example, Romovac) will be placed in all cases and managed per protocol.

Postoperative Assessment and Data Collection:
Daily clinical assessments will be conducted by a blinded infectious disease specialist and a nurse who are not involved in the surgery or randomization process. Wound evaluation will be performed on postoperative day 3, on the day of discharge, and on postoperative day 30 at the outpatient follow-up visit. SSI classification will follow CDC criteria (superficial, deep, organ or space). Suspected wound infections will be documented and sampled for culture and sensitivity. Data will be recorded in structured case record forms and entered into a password-protected database.

Follow-Up Schedule:
Day 0 to discharge: Inpatient monitoring.
Day 3 and Day 7: Inpatient wound inspection.
Day 30: Outpatient wound assessment.
Unscheduled visits: Additional review if infection symptoms arise such as fever or wound discharge.

Laboratory Investigations:
Preoperative: Complete blood count, serum creatinine, liver function tests, and C-reactive protein.
Postoperative: Complete blood count and C-reactive protein as clinically indicated.
Microbiology: Pus or wound swab cultures in cases of suspected SSI.

Outcome Measures:

Primary Outcome:
Incidence of SSIs within 30 days postoperatively (CDC criteria).

Secondary Outcomes:
Classification and timing of SSIs.
Length of hospital stay.
30-day morbidity using the Clavien-Dindo classification.
Drain site infection rate.
Need for antibiotic escalation, readmission, or reoperation.
CRP and WBC trends, severity of SSI, and adverse events.

Impact of the Study:
This study may provide evidence for a low-cost, safe, and effective strategy to reduce SSIs following oncologic laparotomy. If beneficial, hypochlorous acid lavage could be rapidly adopted into surgical practice, improving patient outcomes while reducing antibiotic use, hospital stay, and healthcare costs.