Pocket closure is a critical aspect of cardiac implantable electronic device (CIED) implantation procedures. Pocket infection is the most feared complication of CIED.The more complex CIED system implanted, the higher is the risk of infection. This observational study, conducted between July 2017 and June 2023, aimed to evaluate the safety and effectiveness of pocket closure using single absorbable 3 layers subcuticular suture Vicryl 3-0 in patients undergoing CIED implantation. A total of 564 consecutive patients were included in the study, with pocket closure performed using three layers of single continuous absorbable subcuticular suture Vicryl 3-0 and followed up on average of 3 years and 2 months. Postoperative outcomes, including the incidence of pocket site infections, device salvage success rate, and device explantation incidences were assessed. Results demonstrated a low incidence of pocket site infections (3.75%) and device explantation (0.34%), with satisfactory device salvage rates (81.9%) among infected cases with overall procedural success of 99.64 %. These findings support the safety and efficacy of pocket closure using absorbable subcuticular sutures in reducing postoperative complications and optimizing outcomes following CIED implantation.

Cardiovascular implantable electronic devices (CIEDs) have revolutionized the management of cardiac arrhythmias and heart failure, providing patients with lifesaving therapies and improved quality of life (Naraen et al., 2023). However, despite their clinical benefits, the implantation of CIEDs is associated with certain procedural risks, among which pocket site infection poses a significant challenge (Phillips et al., 2022). Pocket infection, characterized by bacterial colonization of the surgical pocket housing the device, is one of the most feared complications of CIEDs implantation due to its potential for serious morbidity and mortality (Baddour et al., 2010).

The risk of pocket infection is influenced by various factors, such as younger age, depressed renal function, immunocompromised state, and prior CIED procedures, however, the complexity of the CIED system being a key determinant (Olsen et al., 2022; Tarakji et al., 2022). Studies have shown that more complex devices, such as implantable cardioverter- defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds) carry a higher risk of infection compared to pacemakers alone (Senaratne et al., 2022). The reported incidence of pocket infection varies across studies, with recent estimates in a large cohort ranging from 1.7% for ICDs to as high as 9.5% for CRT recipients over a two-year period (Nielsen et al., 2015).

Traditionally, pocket closure techniques have involved the use of interrupted absorbable sutures for subcutaneous tissue and non-absorbable mattress silk sutures or staples for skin closure (Goto et al., 2020). However, emerging evidence suggests that alternative closure methods may offer advantages in terms of infection prevention and wound healing. In particular, the use of single absorbable subcuticular suture, such as Vicryl 3-0, has garnered interest of its potential to reduce the risk of infection and improve overall procedural outcomes, very limited data is available for its efficacy in cardiac surgery (Zhang et al., 2018).

In this study we present our experiences with pocket closure using a single absorbable subcuticular suture, Vicryl 3-0, across various centers in armed forces and civilian settings. The primary aim of this observational study was to assess the effectiveness of pocket closure using single absorbable 3 layers subcuticular suture Vicryl 3-0. 

Study Design and Setting: 

This observational study was conducted across multiple health centres of armed forces institutions in India (depending on operator’s place of posting), over a period of six years. The study protocol was approved by the institutional review board or ethics committee at each participating centre.

Study Population: 

The study included patients of all ages and genders undergoing CIED implantation procedures including pacemakers, ICDs, and CRT-D devices for various indications. A total of 564 cases were included in the analysis, with patients enrolled consecutively during the study period (July 2017 to June 2023) and followed up till March 2024. Patients with a history of previous CIED implantation or those undergoing device revision procedures were excluded from the study. Informed consent was obtained from all included patients prior to their enrolment.

Pocket Closure Technique: 

All CIED implantation procedures were performed by a single operator using a standardized technique. Pocket closure was achieved using three layers of single continuous absorbable subcuticular suture. The primary intervention of interest was the use of Vicryl 3-0, for closure of the surgical pocket following CIED implantation. 

Device Salvage Procedure:

The procedure entailed the removal and cleaning of tissue around the device, followed by the formation of a subpectoral pocket beneath the pectoris major muscle. The CIED was then relocated to this newly created pocket, ensuring complete muscle coverage, and the skin was closed without undue tension.

Data Collection: 

Data on patient demographics, clinical characteristics, procedural details, and post-operative outcomes were collected prospectively. Patients demographics included age, gender, and comorbidities such as diabetes mellitus and anticoagulant therapy. Procedural details encompassed the type of CIED implanted, indication for implantation, and concomitant medications. Postoperative outcomes assessed included the incidences of pocket site infection, device salvage success rate, and device explantation incidences.

Outcome Measures: 

The primary outcomes of interest were the effectiveness of pocket closure and incidences of pocket site infection, defined as the presence of localized erythema, swelling, tenderness or purulent discharge at the surgical site requiring intervention. Secondary outcomes included the success rate of device salvage procedures, defined as the proportion of infected devices salvaged without the need for explantation, and the incidence of device explantation due to pocket site infection or other complications. Device salvage was done by negative pressure wound therapy (NPWT), which is helpful in treating pocket site infections by promoting wound healing through continuous or intermittent negative pressure. This therapy helps remove exudate, reduce edema, increase blood flow and draw the edges of the wound together, thereby reducing the bacterial load and promoting a cleaner wound environment.

Statistical Analysis: 

Descriptive statistics were used to summarize patient’s demographics, clinical characteristics, and procedural outcomes. Continuous variables were presented as mean ± standard deviation or median (interquartile range), while categorial variables were presented as frequencies and percentages. Comparative analysis was performed using appropriate statistical tests, including chi-square tests for categorical variables and t-test or Mann-Whitney U tests for continuous variables. A p-value ≤0.05 was considered statistically significant.

Fig 1: Pocket closure and follow-up

Fig 2: CIED device salvage after infection

Table 1: Patients baseline characteristics

Data are presented as mean standard deviation for continuous variables.

Number in parenthesis are percentage. PCI-Percutaneous coronary intervention, CABG-Coronary artery bypass graft surgery, TAVR-Transcatheter aortic valve replacement

Table 2: Various CIED implanted in patients

AICD- Automated implantable cardioverter- defibrillators, PPI- Permanent pacemaker implantation, CRT- Cardiac resynchronization therapy, PGR- Pulse generator replacement

Table 3: Infection rate among CIED implanted patients

CRT- Cardiac resynchronization therapy, AICD- Automated implantable cardioverter- defibrillators, PGR- Pulse generator replacement

Table 4: Age-wise distribution of patients with CIED pocket infection

Study Population Characteristics:

A total of 564 patients undergoing CIED implantation were included in the study. The median age of the study population was 66 years, with a range from 4 to 92 years, out of which 40.3% were female. Additionally, 27.2% of patients had diabetes mellitus. The proportion of patients on antiplatelet therapy for prior PCI/CABG/TAVR was 14.5%, and 3.36% of patients were on oral anticoagulants, data shown in Table 1. 

The distribution of CIEDs among patients has been depicted in Table 2. The highest number of people received PPI followed by ICD.

Postoperative Management:

The first dose of antibiotics (Injectable Teicoplanin or Linezolid and Amikacin or Ceftriaxone, weight and creatinine clearance-based dosage,) was given intravenously an hour preoperatively and then for 5 consecutive days, and thereafter oral antibiotics (Ceftum and Linezolid) for another 5 days. For the wound care, first dressing was done on day 3 and most of the patients were discharged on 5th day after their 2nd wound dressing. All the patients were called for review after 1 week of discharge and then after a month. The average hospital stay for patients was 5.7 days. The follow up period varied between 6 months to 6 years with no mortality (reference wound closure image shown in Figure 1).

Pocket Infection Rate:

Of the 564 patients included in the study, no patient had early pocket infection (immediate or within first month of device implantation). Though 21 patients (3.75%) developed pocket site infections following CIED implantation after an average of 7±0.27 months (minimum duration of 2 months and maximum of 10 months), with no mortality at average follow up of 3 years and 2 months (minimum follow up duration of 6 months to maximum 6.5 years). 

For every patient presented with infection was confirmed with microbial culture test and mean while broad-spectrum antibiotics (Inj Meropenam 1 gm TDS and Inj Teicoplanin 400mg BD on day 1 f/b 400 mg OD) were prescribed to the patients, and afterwards as per the culture sensitivity report antibiotics were modified to treat the patients. Burkholderia cepacia was one of the common bacteria found positive in the samples. Among these 21 infected patients, 10 cases were superficial, confined to skin and did not communicate with the pocket. These superficial infections were managed with prolonged antibiotic therapy and wound dressing as per the microbial culture findings. These patients required an additional week of hospitalization. The remaining 11 cases were deeper infections involving the surgical pocket.

Among 21 patients with pocket site infection, 11 patients were diabetic, 7 were on antiplatelet therapy and 3 were on anticoagulant therapy. The highest number of infections were observed in patients with ICDs and pacemakers.  These findings have been shown in Table 3. The age-wise distribution of infected patients has been shown in Table 4.

Device Salvage Success Rate:

Of the 11 patients who developed pocket site infections were treated with the help of reconstructive surgeon pocket deep below pectoralis major muscle (sub-pectoral) and with NPWT, 9 patients underwent device salvage procedure with subpectoral pocket creation and NPWT (reference image shown in Figure 2). This resulted in a device salvage success rate of 81.9% among infected cases.

Device Explantation Incidence:

Overall, 2 patients (0.34%) required device explantation due to persistent or severe infection. The indication of device explantation was related to pocket site infection in both cases. One of the patients was 68 years old diabetic and another was of 45 years of age on antiplatelet therapy. 

The use of Vicryl 3-0 in pocket healing for all cardiac implantable electronic devices achieved an overall success rate of 99.64% among patients.

The findings of this study contribute to the evidence supporting the safety and efficacy of pocket closure using absorbable subcuticular sutures in patients undergoing CIED implantation. Our results demonstrate a low incidence of pocket site infections and device explantations, with satisfactory device salvage rates, following the implementation of this closure technique. These findings are consistent with previous studies that have evaluated the utility of absorbable sutures in reducing postoperative complications and improving wound healing outcomes in various surgical procedures (Gurusamy et al., 2014; Sajid et al., 2014).

Several studies have investigated the role of absorbable subcuticular sutures in promoting wound healing and reducing infection rates in surgical patients. For examples, a retrospective study by Zhang et al found that Vicryl sutures were associated with lower rates of wound complications and improved cosmetic outcomes compared to non-absorbable sutures in patients undergoing skin closure after breast surgery. Similarly, a systemic review and meta-analysis by Ahmed et al and Chang et al reported that absorbable sutures were associated with reduced rates of surgical site infections and wound dehiscence in various surgical specialities (Ahmed et al., 2019)

This study extends these findings to the context of CIED implantation, where pocket site infections pose unique challenges due to the presence of implanted electronic devices. By employing absorbable subcuticular sutures for pocket closure, we aimed to minimize tissue trauma, foreign body reaction and suture related complications, thereby facilitating optimal wound healing and reducing the risk of infection.

Device salvage procedures, including subpectoral pocket creation and NPWT, played a crucial role in managing pocket site infections and preserving implanted devices in our study. The success of these salvage techniques highlights the importance of multidisciplinary collaboration and individualized patient management strategies in optimizing outcomes following CIED implantation. Our findings are consistent with previous studies that have demonstrated the efficacy of device salvage procedures in minimizing the need for device explantation and reducing patient morbidity(Chatterjee et al., 2021; Jung et al., 2017) . 

Despite the promising results of our study, several limitations could be acknowledging. The observational nature of the study design precludes casual inference, and the potential for selection bias and confounding factors cannot be entirely ruled out. Additionally, the relatively small sample size and single centre setting may limit the generalizability of the findings. Future research, including randomized controlled trails are warranted to confirm these findings and provide evidence-based practice in CIED procedures.

In conclusion, the pocket closure using absorbable subcuticular sutures, such as Vicryl 3-0, is a safe and effective technique for reducing pocket site infections and device explantation in the patients undergoing CIED implantation. The findings of this study support the adoption of this closure technique in clinical practice and highlight the potential benefits of device salvage procedures in managing pocket infections. By optimizing the pocket closure techniques and individualizing patient management strategies, the clinical outcomes can be improved, and patient satisfaction can be enhanced.

We would like to extend our heartfelt gratitude to all individuals and institutions that have contributed to the successful completion of this research. We are deeply appreciative of the invaluable guidance and insightful feedback provided by Dr Parag Barwad, Additional Professor Cardiology, Advanced Cardiac Centre, PGIMER Chandigarh, India.