Introduction
Treatment of pressure sores (PS) is a challenge for plastic surgeons due to the tendency for recurrence [
1]. Surgical management of the PS is controversial. Differences of opinion exist about what type of reconstruction should be done. However, for full thickness pressure sores, surgery remains the best option. Indeed, conservative treatment increases the possibility for early recurrence as healing by secondary intention usually results in unstable scars [
2]. In these cases, both myocutaneous and fasciocutaneous flaps have been used successfully. These flaps provide bulk eliminating dead space, adequate blood supply to overlying soft tissues, and resistance to infections [
3].
The gluteal thigh (GT) flap was described by Hurwitz in 1980 for perineal and ischiatic reconstructions. It is a fasciocutaneous flap based on the descending branch of the inferior gluteal artery. Described more recently, the IGAP flap is a perforator flap based on perforating branches from the inferior gluteal artery. The main advantages are derived from the reduced donor site morbidity. In our experience, both flaps are reliable and predictable, representing adequate choices for ischiatic and perineal reconstructions.
The reconstructive surgeon is constantly challenged to investigate and develop techniques to improve functional and esthetic outcomes. Utilizing the IGAP and GT flaps for ischiatic and perineal defects, reconstruction provides appropriate functional outcome while preserving local muscle function. Although reconstruction with local flaps is a well-described procedure and there are previous series evaluating the surgical results [
4–7], there are few reports comparing the anatomy of GT and IGAP flaps [
8,
9]. Moreover, less information is available concerning the surgical planning outcome of large wound reconstruction with these flaps. Thus, the purpose of this article is to describe the main anatomical parameters in cadavers to establish landmarks to flap dissection and report our clinical experience focusing attention on preoperative planning, outcome, advantages, and limitations of both techniques.
Discussion
Pressure sore surgery remains a challenge for plastic surgeons due to the tendency for recurrence. The reported prevalence is high as 26% among hospitalized patients and 39% among patients with spinal cord injuries [
10,
11]. Additionally, the complications and the recurrence rates are the major problems following surgical treatment, which are previously described variedly from 7 to 62% [
12,
13].
Many options are available for surgical management of PS, including direct closure, skin grafting, fasciocutaneous flaps, and musculocutaneous flaps. Immediate postoperative complications and ulcer recurrence rates at follow-up have been remarkably high, particularly in patients with spinal cord injuries. In spite of these limitations, these high incidences can be reduced by comprehensive care provided by the multidisciplinary team. With adequate knowledge of surgical techniques and particularities of each region to be treated, a satisfactory long-term outcome can be obtained.
While treating ischiatic and perineal defects, both fasciocutaneous and muscle flaps can be selected. The decision to use a particular flap depends on the surgeon’s expertise and on patient and ulcer characteristics. Many flaps have been described to treat PS in these regions. Muscle flaps such as the hamstring, gracilis, and the gluteus maximus have been used in the spinal cord injury population with success. For ambulatory patients, muscle flaps should be avoided to preserve function. Traditionally, the myocutaneous flap has been described as the first choice, by eliminating the dead space, providing adequate blood supply to overlying soft tissues, and superior resistance to infections [
3]. However, Thiessen et al. in a large study of 94 PS reconstructions utilizing myocutaneous and fasciocutaneous flaps observed that complication and recurrence rates were not associated with the type of the flap [
14].
Gluteal flaps have been largely utilized in reconstructive surgery [
15]. However, flap dissection is difficult, and exposure of the donor vessels risks injury to the adjacent sciatic nerve. In addition, partial resection of the gluteus maximus muscle results in weakness of thigh abduction and extension in ambulatory patients. Recently, the IGAP flap has been used to repair pressure sores [
16]. This flap can be harvested without significant damage to associated muscles, thereby reducing the postoperative morbidity. However, the variable anatomy and the necessity for intramuscular dissection of perforators have been described as the main limitations of the procedure. In recent years, perforator flaps have been widely used in reconstructive surgery becoming the gold standard in many areas.
The major advantage of fasciocutaneous and perforator flaps is the preservation of the underlying muscle, which is particularly important to ambulatory patients and patients with a high tendency for recurrence. In case of a recurrence, these flaps can be readvanced as random flaps. In terms of perineal defects, a thin flap is the ideal alternative. It requires a simple and safe procedure with minimal invasion and preserves the underlying donor tissues for further reconstruction. For the ischiatic region, depending on the depth of the defect, more bulk is required.
The anatomical study showed that the IGAP flap is thicker than the gluteal thigh flap in both its proximal and distal portions. This fact can be explained by the distribution of the fat in the body. While in the gluteal region the subcutaneous tissue is thick, in the posterior thigh region, the thickness decreases from proximal to distal. The indication of the IGAP flap as the first option to cover ischiatic pressure sores can be done based on the like with like concept. When selecting the gluteal thigh flap, the thickness can be increased through deepitelialization and folding of the distal portion of the flap [
17].
Flap dimensions obtained through the pinch test showed that the IGAP has a bigger cutaneous island when compared to the gluteal thigh flap (216 cm 2 × 160 cm2). The IGAP is a wide flap while the gluteal thigh has its width limited by skin elasticity of the thigh region. On the other hand, the length of the gluteal thigh is bigger than that of the IGAP flap. As a consequence, each flap should be indicated for a certain type of defect. In clinical practice, both of the flaps are suitable for the treatment of most of the defects located in the ischial and perineal areas. The IGAP flap has the advantage of multiple designs of the skin island while the gluteal thigh has an almost fixed design.
Comparison between the vascular pedicle of the flaps is difficult due to the distinct anatomical features. The gluteal thigh flap is a fasciocutaneous flap based on the descending branch of the inferior gluteal artery. The pedicle has a short intramuscular course and a long fasciocutaneous course. The IGAP flap is based on a perforator pedicle with origin in the inferior gluteal artery and a long intramuscular course. The differences become clear when the length of the pedicles is compared. The gluteal thigh has a longer pedicle (23.12 cm) and the IGAP has a shorter pedicle (7.78 cm). In our paper, the length of the IGAP flap pedicle is shorter than previously described because the dissection was not continued to the origin in the inferior gluteal artery to preserve the descending branch [
18].
We would like to acknowledge some limitations of the paper. It is an anatomical study performed in fresh cadavers, which facilitates the dissection and measures when compared with the ones done in preserved cadavers. It is possible that the dimensions of the skin islands obtained through the pinch test do not correspond to the real size observed during dissection of the flaps. Clinical application has proved both flaps to be safe and larger than observed during the dissections as previously demonstrated by many authors [
19‐
25].
Conclusion
IGAP flap is thicker and has a shorter pedicle than the gluteal thigh flap. These features and the fact that the IGAP flap is closer and similar to the tissues lost to the pressure sore make it the first choice to treat ischiatic pressure sores. The gluteal thigh flap, due to the reduced thickness, longer pedicle, and wider arc of rotation, should be regarded as an option on recurrent sores or in patients presenting ulcers located in the medial parts of the perineum.
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.