Incisional Negative-Pressure Wound Therapy for Perineal Wounds After Abdominoperineal Resection for Rectal Cancer, a Pilot Study

Abstract

Objective: Abdominoperineal resection (APR) is associated with high incidence of surgical wound infections. The use of incisional negative-pressure wound therapy (iNPWT) is known to reduce wound infections for several surgical indications. The aim of this pilot study was to investigate the potential of a new portable negative-pressure therapy device on perineal wound healing in patients undergoing APR.

Approach: A new single-use incisional negative-pressure therapy device was applied in 10 patients. A negative pressure of −80 mmHg was continued for 7 days postsurgery. Incidence of wound complications and time to wound healing were compared with a historical control group of 10 patients undergoing APR in 2014, treated with conventional wound care.

Results: Patient characteristics were comparable in both groups. Mean 1.6 dressings were used per patient. A wound complication was diagnosed in seven patients versus six in the control group. Wound infections were diagnosed median 11.5 days after surgery, compared with 10.5 days in the control group. Duration of wound healing was shorter in the study group (median 8.5 weeks vs. 13 weeks).

Innovation: This is the first study to report on the use of this iNPWT device for patients who underwent APR for rectal cancer.

Conclusion: In this study, iNPWT did not reduce wound complications. Wound infections occurred slightly later and seemed to have a less severe clinical course. After treatment with iNPWT, the duration of wound healing was shorter.

Introduction

Surgical resection of the rectum for rectal cancer via abdominoperineal resection (APR) is associated with high rates of perineal wound complications, reported to be 14–80%.¹ This may be caused by the large cavity in the pelvis that exists after resection, where blood and fluid can accumulate and accelerated bacterial growth can occur subsequently. Furthermore, neoadjuvant treatment for rectal cancer is a known risk factor for perineal wound complications.² Other patient-related risk factors for perineal wound complications include diabetes mellitus, malnutrition in cancer patients, obesity, smoking, hypertension, and hypercholesterolemia.^3–5 Perineal wound infections are known to lead to decreased postsurgical quality of life, prolonged hospital stay, intensive wound care, and sometimes, even require reconstructive surgery.⁶

Clinical problem addressed

Perineal wound complications after APR for rectal cancer occur frequently and are known to have a prolonged impact on postoperative recovery and quality of life. The use of negative-pressure wound therapy (NPWT) to support wound healing has been described for many indications, including acute and chronic wounds.⁷ Over the last two decades, there has been an increase in development of commercially available negative-pressure devices, including devices that can be applied to closed incisions to prevent wound complications, so-called incisional NPWT (iNPWT).

The aim of this study was to evaluate the potential of a new portable NPWT device in reducing wound complications and accelerating wound healing for patients undergoing APR for rectal cancer.

Materials and Methods

This is a single center prospective feasibility study conducted between January 1st and December 31st 2015 at IJsselland Hospital, The Netherlands. The use of the disposable PICO™-device was evaluated in 10 patients undergoing laparoscopic APR for rectal cancer. Patients undergoing extralevator APR or treated with a perineal subcutaneous drain were excluded. Primary endpoint was the incidence of wound complications. Secondary endpoints were wound complication severity score assessed with the Clavien–Dindo classification (CD)⁸ and time to wound healing, defined as time to complete closure of the wound. Outcomes were compared with a historical control group of patients undergoing APR in 2014 and treated with conventional wound care.

A new portable iNPWT device

The PICO system (Smith & Nephew, London, United Kingdom) is a disposable NPWT device, designed for open and closed surgical incisions. The PICO pump generates a preset negative pressure of −80 mmHg and is designed for 7-day use. This device is portable, ultralight, and canister-free. The PICO system was shown to be effective in reducing wound healing problems in small series of various specialties: orthopedic surgery, cardiothoracic surgery, and plastic reconstruction.^9–12 The work-mechanism of the PICO-NPWT is different from other NPWT systems, as it is canister-free, but it is similar with regard to fluid evacuation, tissue contraction, and changes in blood flow.¹³

Surgical procedure

All patients underwent elective laparoscopic APR for distal rectal cancer. Patients received one dose of antibiotic prophylaxis before surgery. The pelvic floor defect was reconstructed primarily or using biologic mesh. For closure of the perineal incisions both absorbable and nonabsorbable stitches could be used. Immediately after closure of the perineal incision, an iNPWT device was applied, in presence of a trained delegate of Smith & Nephew and a surgeon (Fig. 1).

Figure 1.

Application of the PICO™ pump directly after surgery.

A negative pressure of −80 mmHg was applied with an intentional duration of 7 days. In female patients a “bridge” between perineal wound and posterior vagina wall was constructed using foam strips to ensure an airtight seal. During postoperative hospital admission, all patients were assessed daily by staff surgeon and specialized nurses. In case of vacuum failure, leakage, or dressing saturation, the dressing was changed. In case of repeated device failure, iNPWT was aborted. Hospital admission was not prolonged for study-related assessments or interventions.

Outcomes

The data of both groups were collected using digital and paper patient records. For statistical analysis of comparison of two means, a two-sided unpaired T-test was used. For comparison of two medians, a Kruskal–Wallis test was used.

Results

Patient characteristics of the study group and the control group were comparable (Table 1). In five patients, the perineal incision was closed using nonabsorbable transcutaneous sutures, and in the other patients, absorbable intradermal sutures were used. In the control group, eight patients were treated with a postoperative intra-abdominal drain, and in four patients, a perineal drain was applied. No biological mesh was used. In seven patients, the perineal incision was closed with absorbable intradermal sutures; nonabsorbable transcutaneous sutures were used in three patients.

Table 1.

Patient characteristics

	Group A (10)	Group B (10)	p
Age mean (range)	65.4 (51–83)	66.6 (45–79)	0.082a
Gender M: F	6:4	6:4
ASA med (range)	2 (1–3)	1.5 (1–4)	0.129b
Charlson index med (range)	4.5 (3–6)	5 (2–7)	0.53a
BMI mean	26.46	26.05	0.85a
Smoking	20%	10%
Cardiovascular comorbidity	50%	30%
Neoadjuvant therapy	40% CRT	30% RT
		20% CRT
T-stage
pT0	0	1
pT1	2	1
pT2	8	3
pT3	0	5
pT4	0	0
Inflammatory disease	20% Crohn's disease

^aTwo-sided unpaired T-test.

^bKruskal-Wallis Test.

ASA, American Society of Anesthesiologists physical status classification; CRT, chemo-radiotherapy; RT, radiotherapy;

iNPWT device

Application of the PICO pump was performed under supervision of a trained delegate from Smith & Nephew directly after closure of the perineal incision. Overall, there were no complaints of pain or discomfort related to the device. Mean time to change of the first dressing was 5.4 days. Six patients completed the 7 days iNPWT with one dressing (Fig. 2), two patients required a second dressing because of saturation. In two patients, a third dressing was necessary, and in one of these patients, NPWT was aborted because of repeated vacuum failure. In one other female patient, wound therapy was stopped because an airtight seal could not be achieved after removal of the urinary catheter. Mean duration of iNPWT was 6.7 days (range 4–8 days). In two patients, iNPWT was continued for 8 days.

Figure 2.

Incisional negative-pressure wound therapy device before and directly after removal at 7 days postsurgery.

Wound complications

A wound complication was diagnosed in 7 out of 10 patients, all classified as CD-grade 1 (Table 2). No reinterventions were performed. Wound infections were diagnosed at median 11.5 days postsurgery (mean 12.6 days, range 5–21 days postsurgery). For one patient, hospital admission was prolonged for adequate wound care, and two patients were readmitted for bedside wound opening, after which they were discharged shortly. Median time to wound healing was 8.5 weeks (mean 10.4, range 0–34).

Table 2.

Presence of wound complications in both groups

	Group A (10)	Group B (10)	p
Wound complications	70% infection	40% infection
Diagnosis (days)	Median 11.5	Median 10.5	0.94a
	Mean 12.6	Mean 10
Time to wound closure	Median 8.5	Median 13	0.87a
	Mean 10.4	Mean 11.4
CD-classification	100% Grade 1	83.3% Grade 1
		16.7% Grade 3B
Intervention	None	1 surgical intervention

^aKruskal–Wallis test.

CD-classification, Clavien–Dindo classification.⁸

In the control group, a wound complication was diagnosed in six patients, of which five were classified CD grade 1. One patient required surgical reintervention under general anesthesia (CD-grade 3B). Two other patients were readmitted for bedside wound opening. Wound complications were diagnosed median 10.5 days after surgery (mean 10 days, range 5–14 days). Median time to wound closure was 13 weeks (mean 11.4 weeks, range 0–24).

Discussion

Patients undergoing APR for rectal cancer remain at high risk of developing wound complications not only due to surgical aspects but also the combination of patient-related risk factors and preoperative chemo–radiation treatment, as is illustrated by this study; 45% of all patients underwent radiotherapy. While previously conducted studies have shown a beneficial effect for conventional NPWT in case of wound complications, it is known that NPWT on perineal incisions can be painful, discourage postoperative mobilization, and especially in woman, it may be difficult to maintain an airtight seal.¹

The new iNPWT device, PICO, is light, portable, and canister-free, and therefore has the potential to be very patient friendly. The use of PICO on laparotomy incisions in patients with Crohn's disease undergoing abdominal surgery was previously studied in Italy, where the authors report a decrease in wound infections as well as hospital stay in patients treated with PICO.^14,15 These studies suggest that PICO can be effective in decreasing wound complications, even in a high-risk population. There are two previously conducted studies that report on the use of iNPWT for perineal incisions after APR.^16,17 In these studies a continuous negative pressure of −125 mmHg was applied for 5 days on primarily closed perineal incisions, leading to a reduction in postsurgical wound complications. Also, the use of variable NPWT was suggested previously.¹⁸ Although there is no evidence from clinical studies yet, porcine wound studies show that variable NPWT increased the amount of granulation tissue.

The aim of this study was to investigate the potential of the PICO device to reduce wound complications in patients undergoing APR for rectal cancer. Because of the small sample size of this pilot study, it was not within our expectation to find statistical significant differences.

When compared with a historical control group, no decrease in wound complications was found in the present study. However, wound infections did seem to occur later in patients treated with iNPWT and appeared to have a favorable clinical course. There were no complaints about device usability and comfort; this is in line with the previously conducted studies.^11,14

In other studies on the effect of iNPWT for perineal incisions after APR, a negative pressure of −125 mmHG was applied.^16,17 Possibly the negative pressure of −80 mmHg that was applied in this study is not sufficient in relationship to the depth and size of the cavity that exist after APR, while it can be effective for other abdominal surgical indications.¹⁴ As iNPWT may facilitate faster superficial wound healing, this possibly counteracts drainage of the exudate in higher tissue levels, causing fluid stasis that subsequently will lead to wound complications. This may explain the slightly later onset of wound infection in the study group. It is possible that the use of wide interrupted sutures facilitates drainage of blood and exudate from the pelvis better than a running suture, which was used in half of our study population. This is the first report on the use of iNPWT for perineal incisions with a canister-free device. The comparison between canister- and canister-free iNPWT should be addressed in future studies. Other recommendations for future research include the role of variable pressure of iNPWT and the effect of interrupted versus running sutures.

Key Findings.

• • iNPWT with the PICO pump was well tolerated.

• • iNPWT did not reduce the incidence of perineal wound complications, but use of iNPWT seemed to result in a reduction of the wound healing time.

• • Perineal wound infections after iNPWT seemed to have a shorter and less severe clinical course.

Innovation

Patients undergoing APR for rectal cancer remain at high risk of developing wound complications. Although present study is too small to draw major conclusions, iNPWT failed to show an evident reduction in wound infection rate. However, it seemed that patients treated with iNPWT had a shorter and less severe course of wound complications. The use of iNPWT seemed to accelerate wound healing. This pilot study may serve as a basis for further research into iNPWT following APR, as the results of this study suggest that there may be a beneficial effect on the course of perineal wound healing.

Abbreviations and Acronyms

APR

abdominoperineal resection

CD

Clavien–Dindo classification

iNPWT

incisional NPWT

NPWT

negative-pressure wound therapy

Author Disclosure and Ghostwriting

No competing financial interests exist. The content of this article was expressly written by the authors listed. No ghostwriters were used to write this article.

About the Authors

Maxime van der Valk, MD, PhD-Student, has worked on this study during her surgical residency at IJsselland hospital, under direct supervision of Maarten Vermaas, MD, PhD. She is now working as a PhD-candidate at Leids University Medical Center. Eelco de Graaf, MD, PhD, Pascal Doornebosch, MD, PhD, and Maarten Vermaas, MD, PhD, are dedicated gastrointestinal surgeons at IJsselland hospital. All authors were closely involved in execution of this study and preparations of the article.