Stool Management Followed by Surgical Debridement and Surgical Closure Combined With Negative Pressure Wound Therapy in the Treatment of Posterior Trunk Pressure Injury: A Retrospective Descriptive Study

Pressure injuries usually occur in patients who are hospitalized or receiving long-term care and, at times, lead to life-threatening complications and even death.^1,2 Pressure injury can cause pain and reduce quality of life, imposing a great burden on patients and the health care system.³

Debridement and dressing are conventional treatments for pressure injury, varying in modality, but neither has been shown to be superior to the other.^4-6 Compared with other treatments that are often time-consuming and sometimes ineffective, negative pressure wound therapy (NPWT) has been used as an adjunctive therapy to improve treatment outcomes.^5,7,8 The mechanism of NPWT includes accelerating angiogenesis, continuously draining exudate, and promoting granulation formation.⁹ Maintaining the seal of NPWT is the basis of its function, and air leakage will lead to interruption of the therapy and risk of contamination. Preventing air leakage is often difficult in certain anatomical areas, moist skin, and complex wounds.^10-12 This challenge is also encountered when applying NPWT in posterior trunk pressure injuries because of moisture, exudation, and fecal contamination.

Fecal incontinence has been demonstrated to be an independent risk factor for pressure injury by producing a detrimental environment.^13-15 Persistent infection can severely delay healing. Fecal diversion is a proposed solution to avoid fecal contaminiation of perianal wounds, but whether it is beneficial to wound healing is controversial.^16,17 In addition, colostomy has many complications and is unacceptable to many patients.¹⁸ Another possible solution is total parenteral nutrition, which can significantly reduce stool production. Although there are some disadvantages and complications, total parenteral nutrition has been shown to be safe and effective as an alternative option.^19,20 Preoperative bowel preparation is often used in colorectal surgery and contributes to reducing surgical incision infections.²¹ However, it is unknown whether total parenteral nutrition after fasting and preoperative intestinal preparation are beneficial when treating pressure injuries.

The purpose of this study was to retrospectively analyze the use of stool management followed by surgical debridement and surgical closure combined with NPWT in patients with stage 3 or stage 4 posterior trunk pressure injuries.

The authors retrospectively analyzed electronic health records of patients with stage 3 or 4 posterior trunk pressure injuries treated with stool management followed by surgical debridement and surgical closure combined with NPWT (VAC Therapy; KCI) in the Second Hospital, Cheeloo College of Medicine, Shandong University from June 2016 to June 2020. The National Pressure Injury Advisory Panel (NPIAP) staging system was used.²²

Inclusion and exclusion criteria. The inclusion criteria were 1) stage 3 or 4 posterior trunk pressure injuries, 2) treatment with NPWT combined with stool management, 3) undergoing treatment until healing was achieved. The exclusion criteria were 1) patients in hospice care with multiple organ dysfunction, and 2) patients who had bleeding disorders or were receiving therapeutic anticoagulation.

Study variables. Variables collected from the electronic medical records included sex, age, height, weight (before and after fasting), initial underlying cause leading to the patient being bedridden, pressure injury stage and location, stool frequency, pathogens, number of NPWT applications, incision dehiscence, incision infection, incision bleeding, subflap hematoma or effusion, outcome, and treatment time. The outcomes were divided into 3 categories: the incision healed without complications, the incision healed after treatment of complications related to surgical closure (defined as complications that occurred from surgical closure until 30 days later), and the patient died. The treatment time referred to the time from the first surgical debridement to the healing of the incision (stitches removed and no residual wound). All patients were followed-up by telephone for 6 months after pressure injury healing, mainly to observe the recurrence in situ.

Statistical analysis. The data were recorded in an Excel (Microsoft) table and exported for analysis by SPSS, version 22.0 (IBM Corp.). Numbers, percentages, and mean were used to analyze patient demographics, initial underlying cause leading to being bedridden, cure rate, pathogens, complications, and NPWT cycles. These patients were divided into 3 groups according to body mass index (BMI; weight in kilograms divided by height in meters squared): underweight (BMI < 18.49 kg/m²), healthy weight (18.5–24.9 kg/m²), and overweight or obese (≥ 25 kg/m²).²³ According to the treatment time, the patients were divided into 3 groups: < 14 days group, 15 to 28 days, and ≥ 29 days group. The difference in body weight before and after fasting was compared using the student t-test. P < .05 was considered statistically significant.

Standard care for all wounds. At the initial physical examination, the location, number, size, depth, and surrounding skin condition of pressure injuries were documented. Wound exudate or deep necrotic tissue were collected for culture for all pressure injuries, repeated 3 times at different sampling times. Before the results were available, broad-spectrum antibiotics were given empirically. Pressure injury stage was determined as stage 3 or stage 4 at the initial physical examination or subsequent debridement. The clinical manifestations of infection and the presence of necrotic tissues were indications for surgical debridement.

As a preoperative preparation, it is critical to comprehensively assess the patient’s general state, correct adverse factors, improve nutritional status, and relieve pain if needed. BMI was used for a rough assessment of the general nutritional status of patients. During fasting patients were given 30 to 35 kcal/kg/day and 1.25 to 1.5 g/kg/day protein (isocaloric amino acids) using 3-in-1 parenteral nutrition to ensure adequate nutritional supply, adjusted according to individual nutritional status.^24,25 Drinking water or oral carbohydrates was allowed depending on the needs of the patient. Cardiopulmonary insufficiency, diabetes, anemia, and hypoproteinemia were addressed so that patients could tolerate anesthesia and surgical procedures.

Stool management strategy. The authors implemented different bowel preparation strategies based on the patients’ different stool frequencies. For patients whose stool interval was 3 days or longer, surgical debridement was scheduled on the same day as an enema was administered. For patients unable to defecate by themselves, artificial assistance or enema was available every 3 days, followed by planned surgical debridement or closure on the same day. Patients whose stool interval was less than 2 days fasted but were allowed to drink and received a residue-free diet from 2 days before the initial surgical debridement until the end of the treatment process. In this way, the stool frequency could be prolonged to more than once every 3 days.

Surgical debridement and closure were scheduled on the same day after each defecation with a preoperative enema. If the above measures could make the patient’s stool interval be between 3 and 5 days and surgical debridement and closure were able to be performed successfully, it was deemed that the goal of stool management had been achieved. However, some patients lost function of the anal sphincter and still had frequent bowel movements after fasting. For these patients, enterostomy was performed.

Procedure for surgical debridement, NPWT, and surgical closure. According to the scope of debridement and the patient’s pain tolerance, local anesthesia combined with sedation or general anesthesia were chosen for all surgical debridements or closures. During the surgical debridement, all necrotic soft tissues and invaded sacrum or ischia were removed, and the underlying cavities or sinuses incised for exploration and debridement. The deep necrotic tissue obtained by debridement was reserved for culture, which was more accurate and had a higher positive rate than the initial culture test results. After debridement, the wound was repeatedly washed with a large amount of normal saline, bleeding was controlled, and the wound was checked carefully to eliminate active bleeding. Then the NPWT device was used.

First, the polyurethane foam was cut into a suitable size and shape, making it 1 cm beyond the edge of the wound to ensure that the wound was filled. A layer of oil gauze containing silver ions was placed between the foam and the wound surface to resist infection and prevent granulation from growing into the foam. Special skills are required to place transparent film around the anus. Initially, the authors used a long strip of film on the skin close to the anus, with attention paid to fully unfolding the skin wrinkles. Then the authors used the film covering the foam to adhere to the above-mentioned adhesive film. A small piece of gauze or cotton ball was placed above the film, fixed on the edge of the anus, with the surface facing the anus open to absorb a small amount of exudate from the anus (Figure 1). The negative pressure was set to -125 mm Hg and applied in continuous mode. Intermittent mode is generally not used, considering that the possibility of leakage in this position is high.

According to the frequency of defecation, debridement combined with NPWT was performed every 3 to 5 days. One to 3 treatment cycles were implemented until the wound exudate culture was negative and the granulation was fresh. That was the first stage. In the second stage, the wound was closed by a skin flap or myocutaneous flap, and incisional NPWT was applied for 5 to 7 days with -125 mm Hg pressure. If the infection and necrotic tissue were limited and the surrounding skin had no obvious inflammation, a primary suture was used with a local flap after radical debridement, as the 2 stages were being implemented at the same time. The foam used as part of NPWT was a 10-cm wide strip that covered the incision.

Ethical considerations. The study followed the Declaration of Helsinki for ethics and was approved by the ethics committee of the Second Hospital, Cheeloo College of Medicine, Shandong University. All patients signed informed consent forms at admission indicating that their medical records could be used for scientific research in the future.

A total of 107 patients with stage 3 or 4 pressure injuries were screened during the study period. Among them, 14 patients had multiple organ dysfunction, 13 patients received anticoagulant therapy, 11 patients stopped treatment because of economic or personal reasons, and 6 patients had thrombocytopenia. Therefore, a total of 63 patients were included for analysis. Among these patients, 35 were male and 28 were female, with an average age of 72.3 ± 11.3 years (range, 20–95 years).

All patients were divided into 3 groups according to BMI: 21 patients (33.3%) were underweight, 24 (38.1%) had a healthy weight, and 18 (28.6%) were overweight or obese. Weight before fasting and after fasting showed no significant difference (62.6 ± 11.2 kg vs 61.6 ± 10.2 kg; 95% confidence interval [CI], -2.78–4.76; P  = .60). Stage 3 and stage 4 pressure injuries accounted for 33 cases (52.4%) and 30 cases (47.6%), respectively. There were 36 (57.1%) pressure injuries located on the sacrum, and the remaining 27 (42.9%) were located in the ischia. Among the initial underlying causes of patients being bedridden, 23 (36.5%) were cardiopulmonary disease, 19 (30.2%) were severe brain damage and cerebrovascular accident, 12 (19.0%) were spinal cord injury, and the remaining 9 (14.3%) were other.

The total culture-positive rate of wound pathogens was 82.5% (52 of 63). There were 50 patients with bacterial infections, with some having mixed bacteria, and 58 strains of bacteria were cultured. Two patients had Candida albicans infection. Among the 60 strains of pathogens, the most common was Escherichia coli (25.0%), followed by Staphylococcus aureus (18.3%) and Pseudomonas aeruginosa (11.7%) (Table 1).

Stool management through fasting and/or enema was achieved in 60 patients (95.2%). Enterostomy was performed in 3 patients (4.8%) with irritable bowel syndrome, and a skin infection developed around the fistula in 1 patient. Before wound closure, 24 patients (38.1%) received debridement combined with NPWT once, 27 patients (42.9%) received this treatment twice, and 12 patients (19.0%) received it three times.

Time between first debridement and complete incision healing was less than or equal to 14 days in 16 patients (26.2%), 15 to 28 days in 35 patients (57.4%), and greater than or equal to 29 days in 10 patients (16.4%). The mean was 22.3 days (Table 2).

Complications associated with surgical closure occurred in 7 patients (11.1%), including 3 patients with partial incision dehiscence, 2 patients with incision infection, and 2 patients with bleeding under flap (Table 3). These complications healed after resuturing the dehiscence or changing the dressing.

Pressure injuries healed in 61 patients (96.8%) (Figure 2 and Figure 3). Two patients died of respiratory failure and pulmonary embolism, respectively, during treatment, when surgical closure was performed but not healed. During the 6-month follow-up, 3 patients (4.8%) experienced pressure injury recurrence (1 patient in the third month and 2 patients in the fifth month). All 3 patients were cared for by one family member, and pressure injury recurred when the repositioning interval was greater than 2 hours. One patient died of pulmonary infection during the follow-up period.

This retrospective descriptive study found that a high healing rate, manageable complications, and rare recurrences were achieved by stool management followed by surgical debridement and closure combined with NPWT. During treatment, patients maintained a good nutritional status through parenteral nutrition and with no significant weight loss.

Enterobacteriaceae and Staphylococcus were the most common pathogens, which is consistent with the results of a comparative study by Heym et al²⁶ on infected pressure injuries in patients with spinal cord injuries. The infection of pressure injuries can spread from contiguous sources of contamination, such as feces.²⁷

NPWT has been shown to reduce the incidence of incision infection. Although the mechanism is not clear, it is speculated that sealing can prohibit bacteria from entering the wound.²⁸ NPWT has been used commonly in the treatment of various chronic wounds,^29,30 but the semiocclusive adhesive dressing encounters fecal contamination when applying it in areas such as the perineum, which causes air leakage and contamination of the wound by feces. Some researchers have improved the filming method or proposed new filming methods. Although the incidence of leakage and feces contamination decreased, it could not be eliminated.^31,32

A possible solution is to divert the stool through a colostomy, but this is controversial. A study showed that colostomy resulted in a shorter healing time and a lower recurrence rate for refractory posterior trunk pressure injuries, but there was a 9.7% incidence of postoperative complications.³³ As shown in the current study, 95.2% of patients had periodic defecation for 3 to 5 days through fasting and/or enema, and only 4.8% of patients with irritable bowel required enterostomy.

There is evidence that insufficient nutritional supply can delay wound healing.³⁴ Therefore, 3-in-1 parenteral nutrition was used for fasting patients to provide 30 to 35 kcal/kg of body weight per day, as recommended by the guidelines.³⁵ This can reduce the risk of contamination due to decreased manipulations and ease of administration.²⁴ A randomized controlled trial showed that there was no significant difference between enteral nutrition and parenteral nutrition in the recovery of critically ill patients in the short term.³⁶ The purpose of fasting is only to reduce stool, so drinking water or oral carbohydrates is allowed, which can alleviate the patient’s thirst and hunger.³⁷

Compared with the work of Detsky et al,³⁸ who evaluated loss of subcutaneous tissue, muscle wasting, and weight loss, the authors evaluated only weight in the current study. Although imprecise, weight can generally reflect the changes in nutritional status. BMI above or below the healthy range is a risk factor of pressure injury.³⁹ In line with this, up to 61.9% of patients in this study had an unhealthy BMI.

Malnutrition is common in patients with pressure injuries. For underweight patients (BMI < 18.5 kg/m²), the authors used current weight as the initial dosing weight. The reason was that calculation of caloric intake based on ideal body weight could induce refeeding syndrome.⁴⁰ For patients with severe malnutrition, surgery should be delayed for preoperative parenteral or enteral supplementation, which may be beneficial to these patients.⁴¹ In the current study, the average weight of these patients decreased slightly after fasting, but there was no significant difference, indicating that the parenteral nutrition provided sufficient calories.

Pressure injuries have a high recurrence rate after healing, but the use of skin flaps or myocutaneous flaps can reduce the recurrence rate, and the adjacent flap or musculocutaneous flap is the priority choice to repair pressure injury.⁴² After closing the wound, incisional NPWT is routinely used, which can reduce the incision tension, promote healing, and reduce the recurrence of pressure injury.^43,44 After repairing the wounds with flaps, 4.8% of patients still had a recurrence.

Surgical closure is used for stage 3 and stage 4 pressure injuries when long-term conservative treatment is ineffective or massive necrotic tissue exists. However, surgical closure–related complications (reported to be as high as 35%⁴⁵), such as wound dehiscence, wound infection, and recurrence, need to be considered fully before surgery. Complications can prolong hospital stay and increase health care costs. Using the procedure described in this study, the incidence of complications related to surgical closure was only 11.1%, and complications were treated conservatively with short total treatment times.

This study was a single-center retrospective analysis, and the sample size was small. The postoperative follow-up time was short, and the long-term effect was not convincing. Prospective randomized controlled trials involving larger samples and longer follow-up times are needed.

A retrospective descriptive study was conducted to analyze the effect of stool management followed by surgical debridement and closure combined with NPWT in 63 patients with stage 3 or stage 4 posterior trunk pressure injuries. A satisfactory cure rate, manageable complications, and rare recurrence were achieved. Parenteral nutrition after fasting can maintain patients’ weight without significant loss. Prospective randomized controlled trials involving larger samples and longer follow-up times are warranted.

Chao Wang, MD^1,2; Jixun Zhang, MD¹; and Zhenzhong Liu, MD¹

¹Department of Burn and Plastic Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China. 

²Cheeloo College of Medicine, Shandong University, Jinan, China.

Address all correspondence to: Zhenzhong Liu, MD, Department of Burn and Plastic Surgery, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, 250033, China; email: drliuzhenzhong@163.com.