Laparotomy, in which the peritoneal cavity is entered through a midline or paramedian abdominal wall incision, remains a cornerstone in the management of a wide range of intra-abdominal pathologies. Despite its routine nature, the procedure carries a persistent risk of postoperative complications, the most frequent and distressing of which is surgical site infection (SSI). SSI prolongs hospital stay, increases healthcare costs and contributes to postoperative morbidity and mortality, and its control is therefore a priority of surgical care, particularly in resource-constrained settings.1-3 In published series, SSI after abdominal surgery has been reported in roughly 5% to 20% of patients, with higher rates after contaminated and emergency operations.4 Its development is multifactorial, depending on patient factors such as obesity, diabetes, anaemia and immunosuppression, and on operative factors such as duration of surgery, degree of wound contamination and surgical technique.5,6 Wound dehiscence is among the most serious complications of laparotomy. It denotes partial or complete separation of the musculo-aponeurotic layers of the abdominal closure, usually within 30 days of surgery, and typically declares itself between the fifth and tenth postoperative day, when the wound is at its weakest phase of healing. It often necessitates re-operation within the same admission and causes marked distress to the patient and the surgeon alike.7 The integrity of the closure during this critical period depends substantially on the control of infection and the prevention of fluid accumulation, particularly in the subcutaneous plane. A subcutaneous seroma or haematoma provides an ideal medium for bacterial growth and compromises the healing process. Fluid collections in the subcutaneous tissue have been linked to delayed healing, wound infection, and subsequent dehiscence or incisional hernia.8 The problem is likely to be greater in India and other developing countries. Malnutrition and anaemia are common and impair collagen synthesis and tissue repair, patients frequently present late with advanced disease and heavily contaminated operative fields, and the associated systemic inflammatory response further disturbs normal wound healing.9-11 The risk of infection is, in addition, related to the virulence of the organisms and the size of the bacterial inoculum introduced during or after surgery. A surgical drain acts on the principle of eliminating the “dead space” created by operative dissection, which otherwise collects interstitial fluid and exudate and serves as a breeding ground for pathogens. By continuously evacuating this fluid, a drain may reduce tissue oedema, improve local perfusion, encourage the formation of granulation tissue and lower the bacterial load.12 Against this, a drain is also a foreign body that provokes a local tissue response, may itself act as a conduit for retrograde infection and can cause discomfort at the insertion site.13,14 It is therefore unsurprising that the evidence is divided. Reviews and meta-analyses have examined subcutaneous drainage extensively,15 a randomised trial in 200 patients found no reduction in SSI with prophylactic subcutaneous Redon drains,16 whereas a more recent randomised trial in contaminated emergency laparotomies reported a substantial reduction.17 Other prophylactic measures, such as incisional negative-pressure wound therapy, have likewise been evaluated with mixed results.18,19 Given this continuing clinical uncertainty, a direct comparison of laparotomy wounds managed with and without a subcutaneous drain is warranted, particularly in a high-risk population such as ours. The present study was designed to determine whether subcutaneous drain placement reduces SSI, seroma and dehiscence after laparotomy, and to assess its effect on hospital stay and its safety, so that postoperative wound care can be guided by evidence. 2. AIM AND OBJECTIVES Aim: To study the use of a subcutaneous drain versus no drain in the reduction of post-laparotomy surgical site infection. Primary objective: To evaluate whether placement of a subcutaneous drain reduces the incidence of wound complications – surgical site infection, wound dehiscence, seroma and haematoma – in patients undergoing laparotomy, compared with standard wound management. Secondary objective: To assess the safety and feasibility of subcutaneous drain placement in laparotomy patients, including adverse events associated with drain insertion and management.

.1 Study design, setting and duration This was a prospective, randomised comparative study with simple randomisation. Patients managed with a subcutaneous suction drain formed the Drain (study) group and those managed without a drain formed the No-drain (control) group. The study was carried out in the Department of General Surgery, K. D. Medical College, Hospital & Research Centre, Mathura, Uttar Pradesh, over a period of 18 months. The hospital is a referral centre for complex cases from Mathura and the surrounding districts, and the study population therefore comprised patients undergoing major gastrointestinal surgery from this catchment area. 3.2 Participants Patients presenting to the Emergency and Outpatient Departments of General Surgery, including those with features suggestive of intestinal obstruction or perforation, were screened against predefined eligibility criteria. Adults aged above 18 years undergoing laparotomy were included. Patients aged below 18 or above 80 years, those with immunocompromised status (HIV infection, or prior radiotherapy or chemotherapy), and those undergoing re-do laparotomy were excluded. 3.3 Sample size and allocation The sample size was calculated using the formula n = Z²pq/d², where Z = 1.96 (standard normal variate at the 5% level of significance), p is the expected proportion based on earlier studies (taken as 6%), q = 1 – p (94%) and d is the absolute precision (5%). This gave n = (1.96)² × 6 × 94 / 5² = 86.6, which was rounded to 87. Eligible patients were allocated by simple randomisation to the Drain group (n = 44) or the No-drain group (n = 43). 3.4 Study procedure and outcome measures Patients in the Drain group had a subcutaneous suction drain placed before skin closure, whereas those in the No-drain group had the wound closed without a drain, in keeping with standard practice. The same surgical team operated wherever feasible, using a uniform operative technique, standardised anaesthesia protocols and consistent postoperative care. The primary outcomes were SSI, seroma, wound dehiscence and length of hospital stay. Secondary outcomes were operative time, intraoperative blood loss, postoperative pain, vital parameters, random blood sugar (RBS), urine output, nausea and vomiting, and drain output. The parameters recorded are listed in Table 1. Table 1. Parameters recorded on the study proforma Phase Parameters Preoperative Age; sex; comorbidities (diabetes, hypertension) with duration and current medication; body mass index; history of previous surgery Intraoperative Presence of adhesions; injury to other organs or regional vessels; duration of surgery; blood loss; drain placed or not Postoperative Pulse rate, blood pressure, temperature, respiratory rate and SpO₂ (1 h, 12 h, 24 h, postoperative day [POD] 1–4); pain on visual analogue scale (VAS) at 1, 4, 12 and 24 h and on days 1–4; nausea/vomiting; RBS; urine output; drain output; signs of wound infection; seroma; wound dehiscence; length of hospital stay 3.5 Data collection, validity and reliability Data were recorded on a pre-designed proforma whose content validity was verified by experts from the Departments of Surgery. Entries were made by a trained research assistant who was blinded to drain status. Internal validity was supported by uniform eligibility criteria, a uniform surgical technique, standardised anaesthesia, calibrated instruments, blinded outcome assessment and consistent postoperative care. Reliability was supported by a structured proforma, staff training, standardised repeated measurements and objective definitions of postoperative complications. Inclusion of both sexes, a wide age range, common comorbidities and a real-world hospital setting was intended to strengthen external validity. A pilot study preceding the main study tested the proforma, recruitment feasibility, the randomisation method and logistics, and helped standardise the surgical and postoperative protocols; pilot patients were not included in the final analysis. 3.6 Ethical considerations The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines. The protocol was reviewed and approved by the Institutional Ethics Committee before enrolment, and written informed consent was obtained from every participant. 3.7 Statistical analysis Continuous variables are presented as mean ± standard deviation (SD) with range, and categorical variables as number (percentage). Categorical variables were compared with the chi-square (χ²) test, or Fisher's exact test where expected cell counts were small. Continuous variables, including operative time and length of hospital stay, were compared with the independent-samples t-test (two-tailed). A p value below 0.05 was considered statistically significant.

A total of 87 patients were analysed: 44 in the Drain group and 43 in the No-drain group. 4.1 Baseline characteristics Age ranged from 19 to 74 years in the Drain group and 19 to 71 years in the No-drain group (Table 2). The mean age was 47.57 ± 15.85 years in the Drain group and 43.14 ± 17.37 years in the No-drain group (p = 0.21), and the distribution across age bands was similar (χ² = 4.24, df = 6, p = 0.64). The commonest age band was 61–70 years in the Drain group (10 patients) and 21–30 years in the No-drain group (10 patients). Table 2. Age distribution of patients in the Drain and No-drain groups Age group (years) Drain (n = 44) No-drain (n = 43) Test / p value ≤ 20 3 (6.8%) 3 (7.0%) χ² = 4.24 21–30 4 (9.1%) 10 (23.3%) df = 6 31–40 9 (20.5%) 7 (16.3%) p = 0.64 41–50 9 (20.5%) 5 (11.6%) 51–60 7 (15.9%) 8 (18.6%) 61–70 10 (22.7%) 8 (18.6%) ≥ 71 2 (4.5%) 2 (4.7%) Mean ± SD (years) 47.57 ± 15.85 43.14 ± 17.37 t = 1.25, p = 0.21 Range (years) 19–74 19–71 Percentages are column percentages. Several age-band cells contain fewer than five patients; the age comparison is therefore best judged from the mean age. Males predominated in both groups: 57 of the 87 patients (65.5%) were male and 30 (34.5%) female. Diabetes was present in 26 patients (29.9%) and hypertension in 22 (25.3%). The groups did not differ significantly in sex, diabetes, hypertension or body mass index (BMI), indicating satisfactory baseline homogeneity (Table 3). Table 3. Baseline demographic and clinical characteristics Characteristic Drain (n = 44) No-drain (n = 43) Test / p value Male sex, n (%) 29 (65.9%) 28 (65.1%) χ² = 0.01, p = 0.94 Female sex, n (%) 15 (34.1%) 15 (34.9%) Diabetes mellitus, n (%) 14 (31.8%) 12 (27.9%) χ² = 0.16, p = 0.69 Hypertension, n (%) 10 (22.7%) 12 (27.9%) χ² = 0.31, p = 0.58 BMI (kg/m²), mean ± SD 24.97 ± 3.86 24.88 ± 3.43 t = 0.11, p = 0.91 BMI range (kg/m²) 17.5–32.7 17.2–31.2 4.2 Intraoperative variables The mean duration of surgery (125.8 ± 27.2 vs 123.9 ± 28.4 minutes; p = 0.75) and mean intraoperative blood loss (412.0 ± 117.4 vs 393.6 ± 115.6 ml; p = 0.46) were comparable between the Drain and No-drain groups (Table 4), so neither is likely to confound the outcome comparisons. Table 4. Duration of surgery and intraoperative blood loss Variable Drain (n = 44) No-drain (n = 43) Test / p value Duration of surgery (min), mean ± SD 125.8 ± 27.2 123.9 ± 28.4 t = 0.32, p = 0.75 Range (min) 83–171 80–178 Blood loss (ml), mean ± SD 412.0 ± 117.4 393.6 ± 115.6 t = 0.74, p = 0.46 Range (ml) 204–596 200–584 4.3 Primary outcomes: SSI, seroma, dehiscence and hospital stay SSI was observed in 18 of the 87 patients. It occurred in 5 of 44 patients (11.4%) in the Drain group and 13 of 43 (30.2%) in the No-drain group, a statistically significant difference (χ² = 4.72, df = 1, p = 0.030; Fisher's exact p = 0.036). This corresponds to an absolute risk reduction of 18.9 percentage points, a relative risk of 0.38 and a number needed to treat of about five (Table 5, Figure 1). Seroma developed in 10 patients overall: 2 of 44 (4.5%) in the Drain group and 8 of 43 (18.6%) in the No-drain group (χ² = 4.23, p = 0.040; Fisher's exact p = 0.049), an absolute risk reduction of 14.1 percentage points. Wound dehiscence was uncommon: 2 of 44 (4.5%) in the Drain group and 3 of 43 (7.0%) in the No-drain group, a difference that was not significant (Fisher's exact p = 0.68). Patients in the Drain group had a significantly shorter hospital stay than those in the No-drain group (8.05 ± 1.78 days, range 6–11, vs 13.02 ± 2.96 days, range 8–17; t = 9.5, p < 0.001), a difference of almost five days (Table 5, Figure 2). The range of stay was also narrower in the Drain group. Table 5. Primary outcomes in the Drain and No-drain groups Outcome Drain (n = 44) No-drain (n = 43) Test / p value Surgical site infection, n (%) 5 (11.4%) 13 (30.2%) χ² = 4.72, p = 0.030* Seroma, n (%) 2 (4.5%) 8 (18.6%) χ² = 4.23, p = 0.040* Wound dehiscence, n (%) 2 (4.5%) 3 (7.0%) Fisher's exact, p = 0.68 Hospital stay (days), mean ± SD 8.05 ± 1.78 13.02 ± 2.96 t = 9.5, p < 0.001* Hospital stay, range (days) 6–11 8–17 * Statistically significant (p < 0.05). Fisher's exact test gave p = 0.036 for SSI and p = 0.049 for seroma 4.4 Postoperative pain Pain scores fell substantially in both groups over the first three days. On postoperative day 1 the mean VAS score was 6.36 ± 0.89 in the Drain group and 6.71 ± 0.77 in the No-drain group (p = 0.053), and on day 3 it was 3.67 ± 0.87 and 3.63 ± 0.86, respectively (p = 0.83), so drain placement did not significantly alter postoperative pain (Table 6). Table 6. Postoperative pain (VAS score, mean ± SD) Time point Drain (n = 44) No-drain (n = 43) p value Postoperative day 1 6.36 ± 0.89 6.71 ± 0.77 0.053 Postoperative day 3 3.67 ± 0.87 3.63 ± 0.86 0.83 4.5 Haemodynamic and physiological parameters Mean pulse rate remained between about 88 and 93 beats per minute in both groups throughout the observation period (Table 7, Figure 3). The Drain group had slightly higher values at 1 and 12 hours and consistently lower values from postoperative day 1 onwards, but no difference was significant at any time point (p > 0.05). Mean systolic blood pressure likewise fluctuated within a narrow range, without a consistent pattern favouring either group (p > 0.05 at all intervals). Table 7. Mean pulse rate (beats/min) and systolic blood pressure (mmHg) over time Time point Pulse: Drain Pulse: No-drain SBP: Drain SBP: No-drain 1 hour 91.3 90.1 116.0 118.3 12 hours 92.6 90.8 122.5 123.3 24 hours 89.8 90.4 118.0 110.3 POD 1 89.6 92.1 122.8 117.8 POD 2 90.1 92.4 124.0 127.3 POD 3 90.2 91.6 121.0 119.0 POD 4 88.7 90.5 118.8 122.8 SBP, systolic blood pressure; POD, postoperative day. No between-group difference was significant (p > 0.05) at any time point. Respiratory rate was similar in the two groups at 1, 12 and 24 hours and on postoperative day 3 (Table 8, Figure 4). It was significantly higher in the Drain group on POD 1 (19.70 ± 2.32 vs 17.00 ± 2.71; p < 0.001) and POD 2 (19.85 ± 3.01 vs 17.60 ± 2.50; p < 0.001), and significantly higher in the No-drain group on POD 4 (20.30 ± 2.00 vs 17.90 ± 2.63; p < 0.001). All values remained within or close to the normal range. Table 8. Respiratory rate (breaths/min, mean ± SD) Time point Drain (n = 44) No-drain (n = 43) p value 1 hour 18.25 ± 2.79 17.40 ± 2.55 0.14 12 hours 18.40 ± 2.54 19.10 ± 2.60 0.21 24 hours 17.80 ± 2.80 17.80 ± 3.19 1.00 POD 1 19.70 ± 2.32 17.00 ± 2.71 < 0.001* POD 2 19.85 ± 3.01 17.60 ± 2.50 < 0.001* POD 3 18.20 ± 2.44 18.80 ± 3.43 0.35 POD 4 17.90 ± 2.63 20.30 ± 2.00 < 0.001* * Statistically significant (independent-samples t-test). Mean body temperature stayed within 36.85–37.20 °C in both groups, with no significant difference at any time point. Mean SpO₂ remained at about 97% throughout; the only significant difference was at 12 hours, when it was marginally higher in the Drain group (97.41 ± 1.30% vs 96.58 ± 1.35%; p = 0.004) (Table 9). Table 9. Temperature (°C) and oxygen saturation (SpO₂, %) (mean ± SD) Time point Temp: Drain Temp: No-drain p SpO₂: Drain SpO₂: No-drain p 1 hour 36.85 ± 0.45 37.00 ± 0.30 0.06 96.68 ± 1.34 97.14 ± 1.41 0.12 12 hours 37.00 ± 0.52 36.88 ± 0.54 0.30 97.41 ± 1.30 96.58 ± 1.35 0.004* 24 hours 37.19 ± 0.45 37.02 ± 0.42 0.07 97.30 ± 1.47 96.95 ± 1.45 0.26 POD 1 37.20 ± 0.33 37.08 ± 0.38 0.12 96.66 ± 1.45 97.09 ± 1.63 0.20 POD 2 36.96 ± 0.34 36.90 ± 0.36 0.42 97.07 ± 1.34 96.91 ± 1.34 0.58 POD 3 37.19 ± 0.38 37.12 ± 0.40 0.39 97.00 ± 1.45 97.09 ± 1.31 0.76 POD 4 36.87 ± 0.45 37.02 ± 0.35 0.09 97.00 ± 1.40 97.02 ± 1.34 0.94 * Statistically significant (independent-samples t-test). 4.6 Random blood sugar and urine output Random blood sugar ranged between about 129 and 143 mg/dl in both groups with no significant difference at any time point (all p > 0.05; Table 10). Urine output was also similar in the two groups at every time point (all p > 0.05; Table 11), indicating comparable fluid balance and renal perfusion. Table 10. Random blood sugar (mg/dl, mean ± SD) Time point Drain (n = 44) No-drain (n = 43) p value 1 hour 134.89 ± 25.62 133.93 ± 25.39 0.86 12 hours 132.75 ± 27.02 133.23 ± 24.91 0.93 24 hours 134.93 ± 28.77 139.21 ± 27.44 0.48 POD 1 135.16 ± 26.62 136.74 ± 27.28 0.79 POD 2 131.34 ± 27.09 140.14 ± 27.60 0.14 POD 3 142.55 ± 23.79 133.28 ± 25.57 0.08 POD 4 129.55 ± 24.28 129.09 ± 23.42 0.93 Table 11. Urine output (ml, mean ± SD) Time point Drain (n = 44) No-drain (n = 43) p value 1 hour 1763 ± 483 1702 ± 533 0.558 12 hours 1534 ± 514 1676 ± 541 0.241 24 hours 1609 ± 499 1673 ± 426 0.572 POD 1 1569 ± 551 1660 ± 511 0.494 POD 2 1601 ± 430 1629 ± 434 0.764 POD 3 1579 ± 475 1707 ± 529 0.201 POD 4 1599 ± 446 1537 ± 468 0.481 4.7 Nausea and vomiting The incidence of nausea and vomiting did not differ significantly between the groups at any time point (Table 12). It was highest on POD 2 in both groups (31.8% vs 32.6%). On POD 3 and POD 4 the No-drain group had numerically higher rates (25.6% vs 13.6% and 34.9% vs 18.2%), but these differences were not significant (p = 0.257 and 0.128). Table 12. Nausea and vomiting, n (%) Time point Drain (n = 44) No-drain (n = 43) p value 1 hour 9 (20.5%) 8 (18.6%) 1.000 12 hours 12 (27.3%) 11 (25.6%) 1.000 24 hours 9 (20.5%) 9 (20.9%) 1.000 POD 1 8 (18.2%) 10 (23.3%) 0.749 POD 2 14 (31.8%) 14 (32.6%) 1.000 POD 3 6 (13.6%) 11 (25.6%) 0.257 POD 4 8 (18.2%) 15 (34.9%) 0.128 Fisher's exact test. 4.8 Drain output In the Drain group the mean recorded drain volume peaked at 72.98 ml at 24 hours and thereafter remained between about 60 and 63 ml through POD 3, with wide inter-patient variability (range 10–118 ml) at every time point (Table 13). Table 13. Drain output in the Drain group (n = 44) Time point Mean (ml) SD Minimum Maximum 1 hour 68.64 33.59 12 117 12 hours 61.95 29.51 12 117 24 hours 72.98 31.09 11 118 POD 1 63.25 33.10 15 118 POD 2 60.16 34.32 13 116 POD 3 61.70 35.13 10 118

Surgical site infection remains one of the commonest and costliest complications after laparotomy, and the role of prophylactic subcutaneous drainage is still debated. In this prospective randomised study of 87 patients, placement of a subcutaneous drain was associated with significantly lower SSI (11.4% vs 30.2%) and seroma (4.5% vs 18.6%) rates and a hospital stay shorter by about five days, with no increase in pain and no adverse effect on vital parameters. The effect on wound dehiscence could not be established because events were few. Valid comparison of two surgical strategies depends on the groups being similar at baseline, and in our study they were: age, sex, diabetes, hypertension and BMI did not differ between groups. This pattern is consistent with other comparative studies of drainage. In a randomised trial of 88 laparotomy patients allocated equally to drain and no-drain groups, mean age was 47.03 ± 16.6 years, close to our 47.57 and 43.14 years, and the arms were balanced for age.20 In a study of 60 patients with peritonitis, males predominated in both arms (70% and 86.7%) without a significant imbalance (p = 0.117), and diabetes (33.3% vs 26.7%), hypertension (30% vs 23.3%) and BMI (25.6 ± 3.9 vs 25.1 ± 3.7 kg/m²) were similarly distributed.21 A study of 100 patients reported a male proportion of 57%, diabetes in 28% and 24%, hypertension in 26% and 24%, and mean BMI of 26.2 and 25.8 kg/m² in the two arms, with no significant differences.22 The male predominance seen in our series (65.5%) mirrors that of these reports. Because diabetes, obesity and advancing age independently predispose to wound infection and poor healing,23 their balanced distribution makes it more likely that the difference in outcomes reflects the intervention rather than patient characteristics. Operative duration and blood loss, which also influence infection risk, were likewise comparable. Published comparisons of subcutaneous drainage seldom report intraoperative blood loss, since drains are intended to influence wound infection and seroma rather than haemostasis; in the randomised study of Farooq et al. in 150 patients, for example, the focus was on SSI, which fell from 46.7% to 13.3% with a drain. Our data indicate that the two groups were operated on under similar conditions. The SSI rate in our Drain group (11.4%) was less than half that of the No-drain group (30.2%). Comparable reductions have been reported by several authors. Farooq et al. found SSI in 13.3% of patients with subcutaneous suction drains versus 46.7% without, in contaminated emergency laparotomies. Barve and Pai reported 20.5% versus 40.9% in a randomised trial, and a study of 100 patients reported 10% versus 42%. In 60 patients operated on for peritonitis, SSI was 16.7% with and 26.7% without subcutaneous negative-suction drainage. A prospective study of 108 emergency laparotomy patients recorded 24% versus 46%.24 The concept has also been explored in colorectal cancer resection,25 ileostomy reversal,26 class IV dirty wounds,27 and in a large single-surgeon series using subfascial drainage,28 and reviews and a large meta-analysis have examined the evidence as a whole. The proposed mechanism is biologically plausible. Dissection creates dead space that fills with serous fluid, blood and exudate, which is an excellent culture medium; continuous evacuation reduces tissue tension and oedema, improves perfusion and removes the bacterial substrate. Our finding that seroma was also significantly less frequent with a drain supports this view, since seroma is the proposed intermediary between dead space and infection. The evidence is, however, not uniform. Baier et al., in a randomised trial of 200 patients, found no significant reduction in SSI with prophylactic subcutaneous Redon drains (9.0% with a drain vs 10.0% without). Such contradictions probably reflect differences in case mix, wound contamination class, baseline infection risk, drain type and duration, and antibiotic and skin-closure practices. A drain is a foreign body that can itself provoke a tissue reaction and act as a route for ascending infection, and the benefit is most plausibly concentrated in high-risk, contaminated or emergency wounds, a point that our study, which did not stratify by contamination class, cannot settle. It should also be noted that the borderline nature of our result calls for caution: the p values for SSI (0.030) and seroma (0.040) are close to the significance threshold, and with Fisher's exact test, which is preferable when expected counts are small, they were 0.036 and 0.049. The direction and size of the effect are encouraging, but the confidence intervals are necessarily wide with 87 patients. Seroma was observed in 4.5% of drained patients and 18.6% of those without a drain. A similar gradient was seen in patients operated on for peritonitis, in whom seroma occurred in none of 30 with a subcutaneous negative-suction drain and in 5 of 30 (16.7%) without one. Studies of closed-suction drainage have likewise addressed seroma prevention after elective abdominal surgery,29 Lichtenstein hernioplasty30 and abdominal closure in obstetric and gynaecological surgery.31 Together with our data, these reports support the role of a drain in preventing subcutaneous fluid accumulation, which is its most direct physiological effect. Wound dehiscence occurred in 4.5% of the Drain group and 7.0% of the No-drain group, a non-significant difference. The number of events (five in all) was too small for a meaningful comparison, and our study was not powered for this outcome. In the 60-patient peritonitis study, dehiscence was likewise not significantly different (about 3.3% vs 6.7%), although SSI was lower with drains. A larger study of 108 emergency laparotomy patients, in contrast, reported dehiscence in 9% with drains and 33% without, a significant difference accompanying a fall in SSI from 46% to 24%. Since infection and fluid collection are important determinants of fascial failure, a benefit of drainage on dehiscence is biologically plausible but requires larger trials to demonstrate. Pain scores did not differ significantly between groups on day 1 (6.36 vs 6.71; p = 0.053) or day 3 (3.67 vs 3.63; p = 0.83). The day-1 p value was borderline and, if anything, pain was numerically lower in the Drain group, which is the opposite of the concern that a drain adds to discomfort.14 A study of subcutaneous drains in class IV laparotomy wounds likewise found no significant effect of the drain on pain while wound infection was reduced.32 These findings suggest that the benefit of drainage does not come at the cost of greater postoperative pain, although few studies have analysed pain in detail. Hospital stay was almost five days shorter with a drain (8.05 vs 13.02 days), with a narrower range, and this was the most statistically robust difference in our study (p < 0.001). A shorter stay with drainage has been reported by others: in the 108-patient study mean stay was 6 days in the drain group and 10 days in controls.24 Shorter stay is plausibly a downstream consequence of fewer SSIs and seromas, which otherwise require wound care, dressings, antibiotics and delayed discharge. However, the size of the difference is larger than that which an absolute 19-percentage-point difference in SSI alone would be expected to produce, and the absolute stay in the No-drain group (13 days) is long. Discharge criteria and the surgeon's willingness to discharge a patient with or without a drain are unblinded decisions and may have contributed. The length-of-stay result should therefore be interpreted together with, and not independently of, the infection data. Pulse rate, blood pressure, temperature, RBS and urine output did not differ significantly between the groups at any of the seven time points, and temperature remained within the normal range in both. This indicates that subcutaneous drainage does not adversely affect haemodynamic stability, glycaemic control or fluid balance, consistent with reports in which wound outcomes differed between drain and no-drain groups without differences in general physiological parameters. Nausea and vomiting were similarly distributed, peaking on POD 2 in both groups. The numerically higher rates in the No-drain group on POD 3 and POD 4 were not significant and may reflect the greater burden of wound complications in that group. Respiratory rate showed statistically significant differences on POD 1, POD 2 and POD 4, in opposite directions, and SpO₂ differed at 12 hours (a gap of under one percentage point). With about 35 comparisons across vital parameters, a few nominally significant differences are expected by chance alone. The values stayed within or close to the physiological range, the direction of the difference changed over time, and neither group showed desaturation. These differences are therefore unlikely to be clinically important, and no correction for multiple testing was applied. Mean drain output was highest at 24 hours (72.98 ml) and remained around 60–63 ml per recorded interval until POD 3, with wide variation between patients. Because the drain was in place and productive through the period in which most SSIs and seromas would be expected to declare themselves, there is a case for protocolised removal, for example on the basis of a defined daily output threshold, rather than removal at the surgeon's discretion. Optimal timing of removal remains unresolved in the literature, and the balance between continued evacuation of fluid and the risk of retrograde infection from a long-standing drain is a question for future trials. Subcutaneous drainage is an adjunct and not a substitute for the established elements of SSI prevention: appropriate antibiotic prophylaxis, meticulous aseptic and atraumatic technique, normothermia, glycaemic control and good perioperative care.33 Within that framework, our findings suggest that a subcutaneous drain is a simple, inexpensive and well-tolerated measure that may lower the burden of wound complications after laparotomy in a high-risk, resource-limited setting. Limitations The following limitations should be considered when interpreting the findings: Single-centre study. The study was conducted at one institution; patient characteristics, surgical technique and perioperative protocols differ between centres, which limits generalisability. Sample size and rare events. The sample size was calculated on a prevalence basis and was insufficient to draw conclusions about infrequent outcomes such as wound dehiscence, or to give narrow confidence intervals for SSI and seroma. Heterogeneity of procedures. The study included a broad range of laparotomies and did not stratify results by type of operation or wound contamination class, which may act as a confounder and conceals possible differences in effect between clean-contaminated and contaminated wounds. Short follow-up. Outcomes were assessed during the immediate postoperative period and hospital stay; long-term complications such as incisional hernia were not evaluated, and infections appearing after discharge may have been missed. Drain protocol. The type of drain, duration of placement and removal criteria were not standardised in the analysis, and variation in these factors could influence outcomes. Blinding and multiplicity. Although the outcome assessor was blinded, the surgeon and usually the patient cannot be blinded to the presence of a drain, which may introduce performance bias, particularly for length of stay. Many secondary parameters were compared without adjustment for multiple testing.

In this prospective randomised study of 87 patients undergoing laparotomy, placement of a subcutaneous drain was associated with a significantly lower incidence of surgical site infection (11.4% vs 30.2%) and seroma (4.5% vs 18.6%) and with a hospital stay shorter by about five days (8.05 vs 13.02 days). The drain did not increase postoperative pain, and pulse rate, blood pressure, temperature, blood sugar, urine output and nausea and vomiting were comparable in the two groups, supporting its safety and tolerability. No significant effect on wound dehiscence could be shown because of the low event rate. On the basis of these results, surgeons may consider subcutaneous drainage in patients undergoing laparotomy, particularly those at high risk of wound complications. Because the study was small, single-centre and unstratified by wound contamination, definitive recommendations require confirmation in large, multicentre randomised trials with standardised drain management. Future studies should also include cost-effectiveness analysis, comparison of drain types and timing of removal, and long-term follow-up for incisional hernia.

1. Sincavage J, Msosa VJ, Katete C, Purcell LN, Charles A. Postoperative complications and risk of mortality after laparotomy in a resource-limited setting. J Surg Res. 2021;260:428-35. 2. Allegranzi B, Bischoff P, de Jonge S, Kubilay NZ, Zayed B, Gomes SM, et al. New WHO recommendations on preoperative measures for surgical site infection prevention: an evidence-based global perspective. Lancet Infect Dis. 2016;16(12):e276-87. 3. Berríos-Torres SI, Umscheid CA, Bratzler DW, Leas B, Stone EC, Kelz RR, et al. Centers for Disease Control and Prevention guideline for the prevention of surgical site infection, 2017. JAMA Surg. 2017;152(8):784-91. 4. Azoury SC, Farrow NE, Hu QL, Soares KC, Hicks CW, Azar F, et al. Postoperative abdominal wound infection – epidemiology, risk factors, identification, and management. Chronic Wound Care Manag Res. 2015:137-48. 5. Seidelman JL, Mantyh CR, Anderson DJ. Surgical site infection prevention: a review. JAMA. 2023;329(3):244-52. 6. Bucataru A, Balasoiu M, Ghenea AE, Zlatian OM, Vulcanescu DD, Horhat FG, et al. Factors contributing to surgical site infections: a comprehensive systematic review of etiology and risk factors. Clin Pract. 2023;14(1):52-68. 7. Sandy-Hodgetts K, Carville K, Leslie GD. Determining risk factors for surgical wound dehiscence: a literature review. Int Wound J. 2015;12(3):265-75. 8. Reiffel AJ, Barie PS, Spector JA. A multi-disciplinary review of the potential association between closed-suction drains and surgical site infection. Surg Infect (Larchmt). 2013;14(3):244-69. 9. Maitra D, Ghosh S, Sarkar S, Ghosh S, Adhikary P, Biswas B. A clinico-microbiological study on assessment of surgical site infection in abdominal and hernia surgery cases admitted in a medical college of Kolkata. J Contemp Clin Pract. 2025;11(6):396-403. 10. Bharati S, Pal M, Sen S, Bharati P. Malnutrition and anaemia among adult women in India. J Biosoc Sci. 2019;51(5):658-68. 11. Larouche J, Sheoran S, Maruyama K, Martino MM. Immune regulation of skin wound healing: mechanisms and novel therapeutic targets. Adv Wound Care. 2018;7(7):209-31. 12. Kosins AM, Scholz T, Cetinkaya M, Evans GR. Evidence-based value of subcutaneous surgical wound drainage: the largest systematic review and meta-analysis. Plast Reconstr Surg. 2013;132(2):443-50. 13. Ward WK. A review of the foreign-body response to subcutaneously-implanted devices: the role of macrophages and cytokines in biofouling and fibrosis. J Diabetes Sci Technol. 2008;2(5):768-77. 14. Gupta P, Kumar R. Role of subcutaneous suction drain in reducing surgical site infections after emergency laparotomy. Int Surg J. 2017;4(8):2717-20. 15. Manzoor B, Heywood N, Sharma A. Review of subcutaneous wound drainage in reducing surgical site infections after laparotomy. Surg Res Pract. 2015;2015:715803. 16. Baier PK, Glück NC, Baumgartner U, Adam U, Fischer A, Hopt UT. Subcutaneous Redon drains do not reduce the incidence of surgical site infections after laparotomy. A randomized controlled trial on 200 patients. Int J Colorectal Dis. 2010;25(5):639-43. 17. Farooq H, Shami AI, Haq BU. Subcutaneous suction drain to reduce surgical site infection in contaminated cases of emergency laparotomy: a randomized controlled trial. Ann PIMS-Shaheed Zulfiqar Ali Bhutto Med Univ. 2025;21(4):683-8. 18. Meyer J, Roos E, Davies RJ, Buchs NC, Ris F, Toso C. Does prophylactic negative-pressure wound therapy prevent surgical site infection after laparotomy? A systematic review and meta-analysis of randomized controlled trials. World J Surg. 2023;47(6):1464-74. 19. Shen P, Blackham AU, Lewis S, Clark CJ, Howerton R, Mogal HD, et al. Phase II randomized trial of negative-pressure wound therapy to decrease surgical site infection in patients undergoing laparotomy for gastrointestinal, pancreatic, and peritoneal surface malignancies. J Am Coll Surg. 2017;224(4):726-37. 20. Barve PM, Pai S. Efficacy of subcutaneous negative pressure suction drainage in preventing superficial surgical site infections following laparotomy: a randomised controlled trial. Karnataka J Surg. 2025;2(2):67-9. 21. Mallaiah B, K BC, J R. A comparative study on subcutaneous negative suction drain vs. no drain in emergency laparotomy wounds for peritonitis. Cureus. 2025;17(5):e84247. 22. Karthick R. A comparative study of subcutaneous single closed suction drain versus simple closure in emergency midline laparotomy wounds [dissertation]. Vellore: Government Vellore Medical College. 23. Manisha, Niharika, Gaur P, Goel R, Lata K, Mishra R. Understanding diabetic wounds: a review of mechanisms, pathophysiology, and multimodal management strategies. Curr Rev Clin Exp Pharmacol. 2024. 24. Ripa MN, Chowdhury N, Quayyum SM, Akbar MA, Azad AK, Wadud F. Effectiveness of subcutaneous suction drain vs. simple skin closure in reducing postoperative surgical site infections after emergency laparotomy. Sch J Appl Med Sci. 2024;10:1386-90. 25. Arslan K, Hasırcı İ, Şimşek G, Ibrahim IA, Şahin A, Eryılmaz MA, et al. Effects of subcutaneous Jackson-Pratt drain on incisional surgical site infection after open colorectal resection for cancer: a prospective, randomized, multicenter clinical study. Indian J Surg. 2021;83(3):712-9. 26. Song JM, Kim JH, Kim MJ, Lim CD, Lee YS. Effectiveness of subcutaneous negative-suction drain on surgical site infection after ileostomy reversal: a propensity score matching analysis. J Clin Med. 2025;14(1):236. 27. Sawada G, Kim HM, Ichikawa Y, Hayashi R, Takata A, Murakami M, et al. Clinical impact of two-week placement of a subcutaneous suction drain in preventing incisional surgical site infection in open gastrointestinal surgery with class 4 dirty wound: a retrospective study. Surg Infect (Larchmt). 2022;23(8):722-8. 28. Isozaki H. Prevention of incisional surgical site infection by subfascial closed suction drainage after open laparotomy: a single surgeon experience in 250 consecutive patients. Patient Saf Surg. 2023;17(1):4. 29. Lasheen AM, Henish MI, Asy AA. Role of subcutaneous suction drain in prevention of wound complications after elective abdominal surgery. Al-Azhar Int Med J. 2023;4(3):33. 30. Sahu V, Saxena A, Agarwal P, Agrawal V, Sharma D. Closed suction drain to prevent postoperative seroma after Lichtenstein hernioplasty in complete inguinal hernia: a comparative study. Greater Mekong Subregion Med J. 2021;1(3):109-14. 31. Vazifdar S, Gavali UG. A prospective interventional study to compare the efficacy of syringe suction drainage system for prevention of subcutaneous seroma formation as compared to abdominal closure without a drain. Int J Reprod Contracept Obstet Gynecol. 2021;10(7):2780-5. 32. Nirupam, Vishwanath G, Shailesh E. A study of effect of subcutaneous drains in class 4 laparotomy wound on clinical outcome. J Indira Gandhi Inst Med Sci. 2020;6(2):153-8. 33. Scott MJ, Aggarwal G, Aitken RJ, Anderson ID, Balfour A, Foss NB, et al. Consensus guidelines for perioperative care for emergency laparotomy Enhanced Recovery After Surgery (ERAS) Society recommendations part 2 – emergency laparotomy: intra- and postoperative care. World J Surg. 2023;47(8):1850-80.