7
Paralysed patients often develop large sacral pressure sores, which are subject to recurrence and which need repeated reconstruction. When large musculocuta- neous flaps (which may be bilateral) are committed primarily, reconstructive possibilities for the future are diminished. Sacral pressure sores may also present in non-paral- ysed patients. It is preferable that these defects are not closed with musculocutaneous flaps in order to spare functional muscle. However, the defects may be too large to be reconstructed with fasciocutaneous flaps. Our experience with the DIEP (deep inferior epigastric perforator) flap and the SGAP (superior gluteal artery perforator) flap in breast reconstruction stimulated us to develop the SGAP flap, which provides an ample amount of tissue with good vascularity, to cover large sacral pressure sores in one stage. This flap is reliably pedicled on a lateral perforator and elevation of the flap does not sacrifice the vascularity or innervation of the underlying gluteus maximus muscle. In our hands, the SGAP flap has now become an important additional tool for the treatment of large sacral pressure sores. The flap has a good range of movement and is easily moved, whilst the donor defect is always closed primarily. We feel that the anatomy is sufficiently straightforward for this flap to be dissected by surgical trainees. Anatomy and operative technique The superior and inferior gluteal arteries (SGA and IGA) are the terminal branches of the internal iliac artery. The SGA gives off a deep branch to the gluteus medius muscle and then runs through the gluteus max- imus muscle, 1 ending in cutaneous arteries mainly located in the superolateral gluteal region. 2 The SGA emerges at the border of the sacrum at the junction of the medial and middle thirds of a line drawn between the posterior superior iliac spine (PSIS) and the apex of the greater trochanter (T) of the femur 1 (Fig. 1). As the SGA supplies the suprapiriformis portion of the gluteus maximus muscle, only perforators located above the piriformis muscle (PM) are used. They are found superiorly to a line drawn between the greater 385 The superior gluteal artery perforator flap: an additional tool in the treatment of sacral pressure sores A. M. Verpaele, P. N. Blondeel, K. Van Landuyt, P. L. Tonnard, B. Decordier, S. J. Monstrey and G. Matton Department of Plastic and Reconstructive Surgery, University Hospital Gent, Gent, Belgium SUMMARY. We describe the use of a large skin–subcutaneous tissue flap based on one perforator of the supe- rior gluteal artery (SGA) to reconstruct large midline posterior defects in one stage. The integrity of the gluteus muscles is preserved and we feel this is particularly important in non-paralysed patients. Donor sites were always closed primarily. Use of the superior gluteal artery perforator (SGAP) flap preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We recommend this flap in an area where reconstructive possibilities are limited, as it pre- serves other reconstructive flap options, both on the ipsilateral and contralateral sides. Keywords: pressure sore, decubitus, sacral, flaps, perforator, superior gluteal artery. British Journal of Plastic Surgery (1999), 52, 385–391 © 1999 The British Association of Plastic Surgeons Figure 1—Anatomical landmarks: the SGA emerges at the junction of the middle and medial thirds of a line drawn between the posterior superior iliac spine (PSIS) and the lateral border of the greater trochanter; the perforators are found superiorly to the piriformis muscle (PM), which is above a line between the top of the greater trochanter (T) and a point halfway between the PSIS and coccyx (C).

The superior gluteal artery perforator flap: an additional tool in the treatment of sacral pressure sores

Embed Size (px)

Citation preview

The superior gluteal artery perforator flap: an additional tool in the treatment ofsacral pressure sores

A. M. Verpaele, P. N. Blondeel, K. Van Landuyt, P. L. Tonnard, B. Decordier, S. J. Monstrey and G. Matton

Department of Plastic and Reconstructive Surgery, University Hospital Gent, Gent, Belgium

SUMMARY. We describe the use of a large skin–subcutaneous tissue flap based on one perforator of the supe-rior gluteal artery (SGA) to reconstruct large midline posterior defects in one stage. The integrity of the gluteusmuscles is preserved and we feel this is particularly important in non-paralysed patients. Donor sites were alwaysclosed primarily.

Use of the superior gluteal artery perforator (SGAP) flap preserves the entire contralateral side as a futuredonor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior glutealartery are still possible. We recommend this flap in an area where reconstructive possibilities are limited, as it pre-serves other reconstructive flap options, both on the ipsilateral and contralateral sides.

Keywords: pressure sore, decubitus, sacral, flaps, perforator, superior gluteal artery.

British Journal of Plastic Surgery (1999), 52, 385–391© 1999 The British Association of Plastic Surgeons

Figure 1—Anatomical landmarks: the SGA emerges at the junctionof the middle and medial thirds of a line drawn between theposterior superior iliac spine (PSIS) and the lateral border of thegreater trochanter; the perforators are found superiorly to thepiriformis muscle (PM), which is above a line between the top ofthe greater trochanter (T) and a point halfway between the PSISand coccyx (C).

Paralysed patients often develop large sacral pressuresores, which are subject to recurrence and which needrepeated reconstruction. When large musculocuta-neous flaps (which may be bilateral) are committedprimarily, reconstructive possibilities for the future arediminished.

Sacral pressure sores may also present in non-paral-ysed patients. It is preferable that these defects are notclosed with musculocutaneous flaps in order to sparefunctional muscle. However, the defects may be toolarge to be reconstructed with fasciocutaneous flaps.Our experience with the DIEP (deep inferior epigastricperforator) flap and the SGAP (superior gluteal arteryperforator) flap in breast reconstruction stimulated usto develop the SGAP flap, which provides an ampleamount of tissue with good vascularity, to cover largesacral pressure sores in one stage. This flap is reliablypedicled on a lateral perforator and elevation of theflap does not sacrifice the vascularity or innervation ofthe underlying gluteus maximus muscle.

In our hands, the SGAP flap has now become animportant additional tool for the treatment of largesacral pressure sores. The flap has a good range ofmovement and is easily moved, whilst the donor defectis always closed primarily. We feel that the anatomy issufficiently straightforward for this flap to be dissectedby surgical trainees.

Anatomy and operative technique

The superior and inferior gluteal arteries (SGA andIGA) are the terminal branches of the internal iliacartery. The SGA gives off a deep branch to the gluteusmedius muscle and then runs through the gluteus max-imus muscle,1 ending in cutaneous arteries mainlylocated in the superolateral gluteal region.2 The SGAemerges at the border of the sacrum at the junction of

385

the medial and middle thirds of a line drawn betweenthe posterior superior iliac spine (PSIS) and the apexof the greater trochanter (T) of the femur1 (Fig. 1). Asthe SGA supplies the suprapiriformis portion of thegluteus maximus muscle, only perforators locatedabove the piriformis muscle (PM) are used. They arefound superiorly to a line drawn between the greater

386 British Journal of Plastic Surgery

Figure 2—Principle of the procedure. (A) The flap is dissected freefrom the underlying gluteus maximus muscle and still perfusedthrough two perforators of the SGA, which emerge from betweentwo separate muscle bundles. (B) The most proximal perforator hasbeen divided to allow maximal medial translation of the flap. (C)The flap is sutured into the defect and the donor site is closedprimarily.

A B

C

trochanter of the femur and a point halfway betweenthe PSIS and the coccyx (C) (Fig. 1).

With the patient in the prone position, the anatom-ical landmarks are drawn and the SGA and its perfo-rators are indicated with the help of unidirectionalDoppler ultrasound. As the arc of movement of theflap is determined by the length of the pedicle, it isimportant to design the flap around the most lateralperforator to create the longest pedicle possible(Fig. 2). The range of the flap is then easily estimated,usually more than 1.5 times the distance between theSGA and the perforator. With this knowledge, one can

plan how long the flap should be designed medial tothe perforator to reach the furthest end of the defect.

We used a conservative approach to the flap,designing the upper border of the flap as a sector ofan imaginary rotation flap (Fig. 3), into which the flapcould be converted should no suitable perforator beencountered during the dissection. This provided thetechnique with an additional safety factor.

The superior border of the flap is incised first,without bevelling, through skin, subcutaneous tissueand fascia to the muscle. From there the flap isdetached from the muscle, until the chosen perforator

SGAP flap in the treatment of sacral pressure sores 387

Figure 3—Postoperative view of a patient in whom no suitableperforator could be found during SGAP flap dissection. Theconservative approach consists of designing the cranial border ofthe flap as a sector of an imaginary rotation flap (arrows), whichcan be used for salvage of the procedure, as demonstrated in thiscase.

Figure 4—Intraoperative view. (A) Shows the freed gluteal musclefibres below, the flap above, well demonstrating the pennateorganisation of the muscle, which is attached to the flap by fibroussepta of perimysium (arrows). The vessel loop is placed around amedial perforator, the scissors are under a lateral perforator, stillencased in its fibrous septum. (B) Pedicle length of 9 cm.

A

B

Figure 5—Intraioperative view showing the important mobilitypotential of the flap through the length of the pedicle. Note thatthe flap is harvested away from the zone of injury, which is locatedoutside of the picture, at the left lower corner.

is encountered. Using loupe magnification, the vesselis then dissected from between the muscle fibres,carefully dividing its small muscular side branches.Usually the vessels lie in a fibrous perimysium, cleav-ing between the muscle fibres3 (Fig. 4A). Once thevessel is found suitable and dissected, the inferiormargin of the flap is incised and the flap is furtherdetached from the muscle. All other branches emerg-ing from the SGA are kept intact, safeguarding theblood supply to the muscle (Fig. 5). No motor nervesare cut in this process. The flap can then be trans-posed into the defect, as demonstrated in Figure 8,and the donor defect closed primarily after minimalundermining. Suction drainage is applied under theflap and in the donor area until less than 10 cc iscollected per 24 h. The patient is kept in a supineposition in an air-fluidised bed for approximately 3 weeks, after which gradual mobilisation of thepatient is begun.

Results

Between April 1996 and February 1998 we used thisflap in 15 patients, of which nine were para- ortetraplegic, and six non-paralysed (Table 1). The age ranged from 20 to 76 years, with a mean age of49.9 years. The flap size ranged between 10 × 7 cm and20 × 9 cm. Pedicle lengths up to 10 cm were achieved.Twelve flaps survived completely. One patient devel-oped a large haematoma under the flap 2 days postop-eratively due to a detached vascular clip. The flap wasultimately lost. Three flaps suffered marginal necrosis,which was debrided with ultimate closure of thedefect. Five patients developed a seroma under anintact flap. After bursectomy, these flaps healed pri-marily, with the exception of one patient with a liverfailure due to alcoholism.

388 British Journal of Plastic Surgery

Table 1 List of patients; mean age is 49.9 years; six patients were non-paralysed, nine patients were paralysed

Number Age P = paralysed Flap size (cm) ComplicationsNP = not paralysed

1 68 P 12 × 15 None2 20 P 11 × 14.5 None3 45 P 20 × 9 Seroma4 76 NP 12 × 10 Haematoma – partial flap necrosis5 76 NP 7 × 10 Seroma6 61 P 14 × 10 None7 59 P 15 × 6.5 Seroma8 20 NP 14 × 12 None9 40 P 13 × 9 Fistula outside flap10 71 NP 13 × 10 Partial flap necrosis – seroma11 60 NP 18 × 11 Seroma12 24 P 15 × 9 None13 30 P 16 × 8 Marginal necrosis14 27 P 18 × 11 None15 72 NP 18 × 8.5 Marginal necrosis – deceased 1 month

postoperatively

Figure 6—Case 1. (A) A large grade III sacral pressure sore in a 69-year-old paraplegic female. The extent of the undermining isindicated by the small arrows. (B) Transposition, without tractionof a SGAP flap (14 × 10 cm) into the defect. The ulcerated areavisible at the lower medial border of the flap was resected beforeclosure. (C) Stable result 18 months postoperatively.

A B

C

Case reports

Case 1

A 69-year-old female with a history of spastic tetraplegia(patient 1, see Table 1) was referred with a large sacral(Fig. 6A) and a smaller trochanteric pressure sore. She wasfebrile upon admission, although there were no signs ofosteomyelitis on bone scan. The bursa of the ulcer was com-pletely excised and a flap of 12 × 15 cm based on a singleSGA perforator was moved into the defect (Fig. 6B), andinset without any tension. The ulcerated area visible at thelower medial border of the flap was resected before closure.The donor defect was closed primarily. After a standard

3 weeks of nursing in an air-fluidised bed, all wounds wereclosed and a stable coverage of the sacrum was provided.The patient was moved into a normal bed with a water-mattress and mobilised gradually. She was discharged to anursing home a few days thereafter. The patient remainsrecurrence-free after 18 months of follow-up (Fig. 6C).

Case 2

Consultation was sought for a 19-year-old male patient(patient 8, see Table 1) who developed a large midline sacralgrade III pressure sore during a 2-month stay in the intensivetherapy unit after polytrauma. Bedside necrectomy, enhanced

SGAP flap in the treatment of sacral pressure sores 389

Figure 7—Case 2. (A) Defect after debridement of a sacraldecubitus ulcer in a 19-year-old non-paralysed male. The flap(arrow) is dissected from a zone not immediately adjacent to thedefect and is ready for transposition. (B) Early postoperativephotograph showing primary healing of all wounds. (C) One yearpostoperatively, the patient is able to stand on the leg of theaffected side, showing no signs of gluteal muscle dysfunction.(D) MRI image, transverse section, of the patient’s gluteal region,19 months postoperatively, showing no significant difference inthickness between the gluteal muscles (GM), nor signs of atrophyor myositis. The flap (FL) is visible in position on the sacrum. Thedonor site scar can be noted as a depression in the subcutis (thickarrow). (E) Coronal section, showing a linear scar in the gluteusmaximus muscle (small arrows).

B

E

A

C

D

nutrition and local treatment for 2 weeks preceded surgicalreconstruction. After debridement, the defect measured 14 ×12 cm (Fig. 7A). It was closed primarily with a unilateralSGAP flap, without any tension on the suture lines. Thepatient could not be positioned in an air-fluidised bed becauseof the presence of external fixation devices and was nursed ona low-airloss bed for 3 weeks. The sutures were then removedand gradual mobilisation was commenced. Healing wasuneventful (Fig. 7B). Eight weeks postoperatively the patientwas walking. After 1 year of follow-up the result remains sta-ble and there is no functional donor site morbidity (Fig. 7C).Nineteen months postoperatively, MRI scan analysis of thegluteal muscles revealed no significant difference in musclethickness or quality. A narrow scar was seen in the donor sitemuscle (Fig. 7D, E).

Discussion

Since Koshima and Soeda reported the feasibility of dis-secting a ‘musculocutaneous’ perforator from betweenthe muscle fibres to produce the first DIEP flap,4 thisconcept has considerably gained in popularity.3,7,8 TheDIEP and SGAP free flaps being the standard proce-dure for breast reconstruction in our unit, we consideredit safe to apply the SGAP flap for coverage of sacralpressure sores. In 1993, Koshima et al published theirearly results with gluteal perforator-based flaps forrepair of sacral pressure sores.2 However, the majority ofKoshima’s patients received a flap based on several per-forators, which needed to be rotated over 60–180° to

390 British Journal of Plastic Surgery

Figure 8—Transposition (interrupted arrows) of a SGAP flap intothe defect (long arrow). Note how the thickness of the flap(opposing arrows) provides ample bulk to fill the defect, which isthe case even in thin patients.

cover the defect. Also, the flaps were taken from theparasacral area, being the zone immediately adjacent tothe injured zone. We found that it is possible to raiselarge skin–subcutaneous flaps, based on one singlemuscle perforator, at a distance from the injured area.

The sliding gluteus maximus musculocutaneous flap,as described by Ramirez et al in 1984, has become awidely accepted procedure for coverage of sacral pres-sure sores in non-paraplegic patients.5 Bilateral muscu-locutaneous flaps have become the standard procedurefor coverage of large sacral defects. The flaps are trans-posed into the defect, taking advantage of the laterallyoblique course of the pedicle. Defects up to 17 cm inwidth were reported to be covered using bilateral slidingflaps.5 A few years later, the same author commentedthat the flap is contraindicated when the defect reachesthe vicinity of the gluteal pedicles.6 The gluteal pedicleshave a length not exceeding 4 cm,1,5 so that a medialtranslation of muscle mass of about 4 cm is the maxi-mum to be expected. As the point of emergence of thesuperior gluteal artery lies 5 cm from the midline,9

defects wider than 5 cm are likely to need a bilateraltransfer. A defect width of 10 cm is the theoretical limitfor coverage of sacral decubitus ulcers with the slidinggluteus musculocutaneous flap, a limitation which isconfirmed by Ramirez himself.6 The sacrifice of gluteusmaximus muscles and thus also future reconstructivepossibilities, the increased blood loss, the increasedoperating time and the tension on the edges of the flapsare other disadvantages of this technique.

By dissecting the perforator vessel from the muscle,a pedicle length of 8.5–10 cm is easily obtained (Fig.4B), giving the flap an impressive mobility and thepossibility of covering large defects with a unilateralflap. As has been determined before, the perforators ofthe SGA mainly perfuse the superolateral glutealregion.2 Choosing a lateral perforator creates thelongest possible pedicle, thereby giving the flap a verylarge arc of movement. This allows the surgeon toreplace the ulcer in most cases with undamaged tissuefrom a distant, untraumatised zone. However, in somevery large defects the margins of the defect need to beincluded in the flap, thereby utilising the skin of thewhole gluteal area.

The main movement of the flap is a translation.Limited rotation of the flap (up to 90°) applies mini-mal torsion to the vascular pedicle, which is, however,of no concern. The flap can be inset without tensionon any of the suture lines and the donor defect can beclosed primarily in all cases. The flaps from this regionhave also been shown to provide more than amplebulk to obliterate dead space, as demonstrated inFigure 8.

The preservation of muscle integrity and musclefunction is one of the greatest assets of the perforatorflap principle. Especially in non-paralysed patientswho will need full function of the gluteal muscles forrecovery of ambulation, the knowledge that functionis kept intact may significantly lower the thresholdtowards decubitus reconstruction with good-qualitytissue. Muscle integrity can be judged intraoperativelyby the colour of the muscle,10 and postoperatively bythe absence of functional problems in the non-paral-ysed patients (Fig. 7C). MRI imaging of the glutealregion shows no significant difference in gluteus max-imus muscle thickness. There are no signs of muscleatrophy or myositis (Fig. 7D). A coronal cross-sectionreveals a narrow scar in the gluteus maximus musclewithout distortion (Fig. 7E).

The dissection of the pedicle takes some time, but isstraightforward as it lies in an avascular plane. Thisgives the additional advantage that the blood loss iskept to a minimum, compared to any gluteus flap ofwhich the dissection of the sacral origin can be quitebloody.

Subcutaneous tunnelling of a de-epithelialised por-tion of the flap should be avoided, as the tunnelledportion may suffer fat necrosis and hence inducewound infection and dehiscence. However, this doesnot appear to compromise the viability of the flap.Seroma formation appeared initially to be a problem.We could detect no clear correlation with age, sex,paralysis, infection or nutritional status. We suspectedthe explanation might lie in the smoothness of theflap’s undersurface, preventing prompt flap adherence.In the last four cases the fascia was partly removedfrom the flap, in an attempt to create a better adher-ence. All these flaps healed without seroma formation.The conservative approach to the flap makes it a safeprocedure, even at the beginning of the learning curve.If no perforators had been found at the expected sites,salvage would have been possible with bilateral rota-tion flaps. The rotation flap suture lines, however,always show some tension and the tip of the flap is lessreliable and less bulky than the SGAP flap would be.

The superior gluteal artery perforator flap providesus with a large, bulky and safe skin–subcutaneous flapto cover sacral pressure sores. There is no significantdonor site morbidity, no bridges are burned andneither muscle nor muscle function is sacrificed.

References

1. Strauch B, Yu HL. Atlas of Microvascular Surgery. New York:Thieme Medical Publishers, 1993; 104.

2. Koshima I, Moriguchi T, Soeda S, Kawata S, Ohta S, Ikeda A.The gluteal perforator-based flap for repair of sacral pres-sure sores. Plast Reconstr Surg 1993; 91: 678–83.

SGAP flap in the treatment of sacral pressure sores 391

3. Allen RJ, Tucker C Jr. Superior gluteal artery perforator freeflap for breast reconstruction. Plast Reconstr Surg 1995; 95:1207–12.

4. Koshima I, Soeda S. Inferior epigastric artery skin flaps withoutrectus abdominis muscle. Br J Plast Surg 1989; 42: 645–8.

5. Ramirez OM, Orlando JC, Hurwitz DJ. The sliding gluteusmaximus myocutaneous flap: its relevance in ambulatorypatients. Plast Reconstr Surg 1984; 74: 68–75.

6. Ramirez OM. The sliding gluteus maximus flap. In: Strauch B,Vasconez LO, Hall-Findlay EJ (eds), Grabb’s Encyclopediaof Flaps, Vol. 3. New York: Little, Brown and Company,1990; 1544.

7. Allen RJ, Treece P. Deep inferior epigastric perforator flap forbreast reconstruction. Ann Plast Surg 1994; 32: 32–8.

8. Blondeel PN, Boeckx WD. Refinements in free flap breastreconstruction: the free bilateral deep inferior epigastric per-forator flap anastomosed to the internal mammary artery. BrJ Plast Surg 1994; 47: 495–501.

9. Minami RT, Mills R, Pardoe R. Gluteus maximus myocuta-neous flaps for repair of pressure sores. Plast Reconstr Surg1977; 60: 242–9.

10. Blondeel PN, Vanderstraeten GG, Monstrey SJ, et al. Thedonor site morbidity of the free DIEP flaps and free TRAMflaps for breast reconstruction. Br J Plast Surg 1997; 50:322–30.

The AuthorsAlexis M. Verpaele MD, FCCP, Consultant Plastic Surgeon,

Phillip N. Blondeel MD, PhD, FCCP, Associate Professor,

Koenraad Van Landuyt MD, FCCP, Associate Professor,

Patrick L. Tonnard MD, FCCP, Consultant Plastic Surgeon,

Benoit Decordier MD, FCCP, Consultant Plastic Surgeon,

Stanislas J. Monstrey MD, PhD, FCCP, Professor and Chief,

Guido Matton MD, FACS, Emeritus Professor and former Chief,

Department of Plastic and Reconstructive Surgery, UniversityHospital Gent, De Pintelaan 185, B-9000 Gent, Belgium.

Correspondence to Dr Alexis M. Verpaele.

Paper received 31 October 1997.Accepted 11 January 1999, after revision.