Random pattern hatchet flap as a reconstructive tool in the treatment of pressure sores: clinical experience with 36 patients

Abstract

Introduction

Pressure sores represent a reconstructive challenge, and the high recurrence rate and need for reoperations should always be considered. Sacrifice of muscle and fascia in primary reconstruction may compromise options for future repairs. The objective of this study was to evaluate the reliability of muscle- and fascia-sparing random pattern hatchet flap reconstruction of pressure sores in different body regions.

Methods

From November 2017 to December 2019, 36 participants with grade III and IV pressure sores underwent random pattern hatchet flap reconstruction. Early postoperative complications and flap survival were evaluated in follow up for 6–12 months.

Results

Thirty-six participants with an age range of 15 to 67 years who presented with pressure sores (13 sacral, 12 ischial, 10 trochanteric, and 1 scapular) underwent surgery. Complete healing of sores was observed within 21 days of surgery in 32 cases and within 30 days for the remaining four cases. Postoperative complications (11.2%) were recorded in only four participants: two experienced partial wound dehiscence, one seroma developed in a trochanteric case, and there was one infection in a sacral sore.

Conclusions

Random pattern hatchet flap is a reliable tool that results in minimal complications for treatment of pressure sores of limited dimensions.

Introduction

Pressure sores are a reconstructive challenge to plastic surgeons. In the United States, approximately 2.5 million pressure sores are treated each year,¹ and they develop in about 9% of all hospitalised patients.² Up to 30% of patients with spinal cord injuries may develop pressure sores within 20 years of their injury,³ with a 20% incidence rate among paraplegic patients and a 26% incidence rate in patients with quadriplegia.⁴ Approximately 75% of all pressure sores develop around the pelvis.⁵ Surgical treatment is usually indicated in type III and IV pressure sores because of the possibility of nonhealing and the need for stable soft tissue cover.⁶ Recurrence rates as high as 80% have been reported.^7,8 This high recurrence rate makes it essential to preserve tissue for future reoperations.

Hatchet flaps allows tissue rotation advancement, thereby providing sufficient mobilisation of tissues with minimal tension on closure. Most current techniques sacrifice underlying muscle or fascia lata in the flap to ensure better blood supply and good bulk for padding.^9–11 In this study, we performed random pattern hatchet flaps to preserve underlying muscles and fascia, as we think it is not necessary to sacrifice them, they will not improve flap survival in small sores and the sacrifice may compromise future options. Daniel et al reported that cutaneous flaps may tolerate pressure ischaemia better than musculocutaneous flaps.¹² The hypoxic distal end of a random pattern flap may be a stimulus for better revascularisation and healing around a pressure sore.^13,14 Tissues surrounding pressure sores have been found to have a robust blood supply due to angiogenic stimulus of the chronic inflammatory process around the wound.^15–17

Methods

Study sample

From November 2017 to December 2019, 36 participants with grade III and IV pressure sores, due to spinal cord injuries and other illnesses, were transferred from Ibn-Alqif Rehabilitation Centre Of Spinal Cord Injuries to the surgical unit of the Al-Kindy Hospital, which is a teaching hospital. Each participant underwent random pattern hatchet flap reconstruction after a full clinical assessment and necessary laboratory tests. A checklist was used to discover the type, duration and dimensions of each sore, along with the spinal cord conditions or other illnesses that may have predisposed the participant to developing pressure sores.

Inclusion criteria

Patients with pressure sores who were clinically fit for surgery. Exclusion criteria: patients who had pressure sores with a diameter larger than 10cm, history of previous pressure sore reconstruction on the same site and those that required flaps that were too thick.

After surgery, all participants were followed up for at least 5 days in the ward. The suction drains were removed at the first outpatient follow-up visit (between 10 and 14 days postoperatively), and sutures and clips were removed according to signs of healing. Participants were advised to keep the wound away from contamination and to avoid pressure on the repair for at least 21 days. All participants were followed up until complete healing was observed.

Operative techniques and surgical steps

Participants were positioned on the operating table in accordance with the location of each pressure sore. The borders of the excision were marked to indicate the scarred wound margins and placement of the incision in healthy-looking skin. The longest and shortest diameters of the anticipated defect were measured and recorded. The hatchet flap incision line was indicated with a curvilinear marking (hatchet shape) starting at the cranial or caudal ends of the longest diameter of the defect, depending on the available donor site. The length of the hatchet incision ranged from three to five times the length of the shortest diameter of the defect (Figure 1). Back-cut incision of the hatchet flap was drawn with a length equal to that of the longest diameter. We kept the flap base (distance between the back-cut incision and the defect) to hatchet incision ratio 1:1.5–2, although it was described that base width could be 1:3.¹⁸

Figure 1 .

Marking of posteriorly based random pattern hatchet flap in trochanteric pressure sore. The excision borders are marked, placing the incision in healthy-looking skin. Marking of the hatchet flap began with the line marked ‘hatchet incision,’ starting from the cranial ends of the defect’s longest diameter. The length of this hatchet incision ranged from three to five times the length of the shortest diameter. ‘Back-cut’ incision line was drawn to a length equal to that of the longest diameter. The flap base (distance between back-cut incision line and the defect) to hatchet incision ratio should be 1:1.5–2.

All operations were done without the need for anaesthesia due to sensory loss in the participants. Intraoperative monitoring and blood transfusion were performed by the anaesthesia team. The ulcer pocket was painted with a diluted solution of methylene blue and hydrogen peroxide to delineate the cavity and create a visual guide for excision. The margins of excision were infiltrated with adrenaline solution diluted to 1:250,000, with a wait time of 10min to achieve better haemostasis. The incision of the marked ulcer was made with en bloc resection of the pouch painted with blue, including a margin of all nonviable bony parts (Figure 2).

Figure 2 .

Surgical steps of anteriorly based random pattern hatchet flap for trochanteric pressure sore. (a) Marking of the surgical planning, the pocket painted with methylene blue. (b) En bloc resection of the pouch painted with blue, including a margin of all nonviable bony parts. (c) Incision of the flap borders to the level of deep fascia. (d) Undermining of the flap above the deep fascia level, extended to the base of the flap. (e) Closure in multiple layers with suction drain fixation.

Next, the flap was incised and dissected above the deep fascia to keep all subcutaneous tissue with the flap. Dissection was extended to undermine the entire marked flap. A suction drain was placed and secured in position, and closure of the defect margins was performed in multiple layers to pull the flap and cover the defect with minimal tension. Usually, enough skin is available to allow direct closure of the donor site in multiple layers. Coated VICRYL^® (polyglactin 910) Suture (Ethicon, Somerville, NJ, USA) was used for deep-layer approximation, and the skin was closed with surgical skin staples. Wound dressing was accomplished using an absorptive nonocclusive dressing. Intravenous broad-spectrum antibiotic prophylaxis continued for 7 days using third-generation cephalosporin. Ischial and sacral pressure sore example cases are shown in Figures 3 and 4.

Figure 3 .

Random pattern hatchet flap covering ischial pressure sore. Preoperative sore (upper left), flap incision and mobilisation (upper right and lower left), tension-free closure (lower right).

Figure 4 .

Random pattern hatchet flap covering sacral pressure sore. Preoperative sore (upper left), flap marking (upper right), tension-free closure (lower left), after 6 months (lower right).

Statistical analysis

Collected data were loaded into IBM SPSS Statistics for Windows, Version 24.0 (IBM Corp., Armonk, NY USA). Data are presented using tables (mean±SD) for numerical data and percentages for categorical data.

Results

Thirty-six participants (32 male and four female) were included in this study with ages ranging from 15 to 67 years (mean±SD=42.56±16.76), all of whom had pressure sores (13 sacral, 12 ischial, 10 trochanteric and 1 scapular) identified as grades III and IV according to the Shea classification (Table 1). The defect surface area ranged from 9.42 to 62.8cm² (25.9±10.19), and the ulcer duration before surgery ranged from 3 to 50 months (22.61±11.32). All participants underwent surgery that used random pattern hatchet flaps. Operative time ranged from 45 to 140min (97.22±19.50).

Table 1 .

Participant and pressure sore characteristics with surgery outcomes data

Number of participants	n=36 (32 male, 4 female)
Age (years)	42.56±16.76
Cause of paraplegia
Spinal cord injury	27 (75%)
Postlaminectomy	2 (5.6%)
Spina bifida	2 (5.6%)
Cerebrovascular accident	4 (11.1%)
Head injury	1 (2.8%)
Pressure sore region
Sacral	13 (36.1%)
Ischial	12 (33.3%)
Trochanteric	10 (27.8%)
Scapular	1 (2.8%)
Defect width×length (cm)	(4.94±1.094)×(6.47±1.108)
Defect surface area (cm2)	25.9±10.19
Ulcer duration before surgery (months)	22.61±11.32
Operative time (minutes)	97.22±19.50
Time to complete healing (days)	21.19±4.07
Follow up (months)	7.58±3.19
Complication type	n=4 (11.2%)
Seroma	1 (2.8%) Trochanteric
Dehiscence	2 (5.6%) Trochanteric
Infection	1 (2.8) Sacral
Complication by region
Sacral	1 (7.96%) of n=13
Trochanteric	3 (30%) of n=10
Ischial	0
Scapular	0

Thirty-two participants achieved complete healing within the first three postoperative weeks, but four participants (11.2%) needed a further week to achieve complete healing. A seroma developed in one of the trochanteric cases, which was treated by aspiration and resolved entirely in the fourth postoperative week. Two other trochanteric cases developed partial wound dehiscence, which were treated with local wound care and achieved complete healing in the next week. The fourth case was complicated by wound infection in a sacral sore and was treated with bedside debridement and frequent changes of dressing with a culture-derived antibiotic. Healing was complete by the fourth postoperative week.

Postoperative follow up of participants ranged from 2 to 12 months (7.58±3.19). The 32 participants for whom healing was uneventful began to sit and lie for short amounts of time on their flaps after three weeks.

Discussion

Pressure sores represent a major reconstructive challenge, and the high recurrence rate should be considered to avoid limiting future options in case of the need for reoperation. Previous studies found including muscle in the transferred flap was not necessary because it was not superior to fasciocutaneous or perforator flaps, and doing so may sacrifice important future options.^19,20

Blood flow in the random pattern flaps is a concern when it comes to reconstructive options. Hatchet flaps in this study were kept thick by including all subcutaneous tissue through dissection in the plane immediately above the deep fascia. This increasing thickness of the random pattern flap ensured safety and was better associated with blood supply than length:width ratio.²¹ Choosing a rotation flap instead of a simple advancement flap has the advantage of a length:width ratio of about 6:1 because of the wide flap base.²² The undermining and back-cut incision was limited to a maximum of 10cm to ensure safe blood supply. Stell predicted that the maximum safe length of a random flap on the human abdomen is approximately 12.5cm.²³

The blood supply around pressure sores is augmented due to the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF). This observation by Pufe paved the way for some authors to try propeller perforator flaps based on newly formed or enlarged perforators in the chronic wound margin.^15,17 These studies indicate robust blood supply around pressure sores and supports our choice of a random pattern flap. In addition, some studies reported that relative ischaemia in the most hypoxic distal portion of the random flaps plays an important role in initiating revascularisation,¹⁴ and may increase the dimensions and quantity of vessels involved in the healing process.²⁴ Because of these studies, we believe that random pattern flap with limited dimensions has an adequate blood supply for pressure sore coverage.

The hatchet flap provides excellent excursion of tissue to cover the wound by recruitment of tissues in combined rotation and advancement with minimal tension at the donor site closure. We did not include fascia in our flaps because the source arteries around the gluteal region are deep to the fascia in underlying muscles, as described by Taylor.²⁵ That means including fascia will not add to the flap’s blood supply and may restrict its pliability when mobilised to cover the defect.

In this study, healing of the flaps was uneventful in the majority of cases (n=32). Only four participants developed early postoperative complications, which were treated conservatively until complete healing, and most of the participants started sitting or lying on flaps for a short time at three to four weeks postoperatively. The overall complication rate in this study was 11.2%, which is less than that found by Thiessen when he compared early postoperative complications in musculocutaneous flaps (56%) and fasciocutaneous flaps (67%).¹⁹ Li et al reported a 23% complication rate after hatchet-shaped tensor fascia lata musculocutaneous flap reconstruction of trochanteric pressure sores.¹⁰ Partial wound dehiscence occurred in two trochanteric cases, and we think that placing the base of the flap on the thigh (anteriorly) increased tension on the repair when the participant extended the thigh, which possibly resulted in dehiscence (Figure 2). In the next eight similar cases, we marked the base of the flap posteriorly toward the pelvis (Figure 1), healing improved, and none of the cases developed dehiscence.

There were no complications in participants with sacral and ischial sores, except for one sacral sore that developed an infection. Dona reported a complication rate of about 11.2% when he used a hatchet-shaped gluteus maximus musculocutaneous flap to treat the same region.¹¹ The operative time and blood loss were much less than in muscle or perforator flaps. In this study, we did not try larger flap dimensions, so reliability for larger sores could not be assessed. And when bulky flaps are needed, musculocutaneous flaps are still preferable. Our follow up was for one year maximum with no recurrence, but we believe longer follow up may be necessary.

Conclusions

Random pattern hatchet flap is a versatile tool that can be applied to a variety of pressure sores. The reliable blood supply and secure tissue mobilisation make it a safe option and should not compromise future reconstruction.

Recommendation

Researchers recommend a larger sample-size study with a longer follow-up period.