The Extended Perineal Turn over Perforator (PTO) Flap: A Novel Technique for Combined Perineal and Vaginal Reconstruction after Extralevator Abdominoperineal Excision (ELAPE)

Aim 

Posterior vaginal wall (PVW) defects have been traditionally reconstructed with rectus abdominis musculocutaneous flaps or with bilateral Singapore fasciocutaneous flaps.¹ Recent evidence support better oncological outcomes by an extralevator abdominoperineal approach, which requires the plastic surgeon to consider alternative options for combined perineal and vaginal reconstruction. The ideal technique reduces donor site morbidity, restores vaginal function and eliminates dead space whilst keeping perineal wound morbidity rates low. This has not been yet addressed in the literature.¹

The Perineal Turn Over perforator (PTO) flap is the workhorse flap in our institution for perineal reconstruction after extralevator abdominoperineal excision (ELAPE).²  We describe a case where an extended version of the PTO flap was used to reconstruct a combined perineal and PVW defect, achieving the above principles.

Case:

A 60-year-old patient was diagnosed with anal squamous cell carcinoma invading the PVW. She had neo-adjuvant chemo-radiotherapy completed 5 weeks pre-operatively. An ELAPE was performed with en-bloc resection of the PVW creating a complex composite perineal and vaginal defect

Technique

A perforator of the internal pudendal artery is identified with a handheld Doppler at the inferolateral part of the skin defect. A semilunar area of skin incorporating the perforator at its base is marked along one side of the perineal defect. The marked skin island is incised down to the supra-fascial layer.

The inferior 5 cm of the skin flap is folded inwards and is sutured to the remaining anterior vagina wall in order to create an adequate vagina allowing for future intercourse. 

The superior 15 cm of the skin flap is de-epithelised and turned over inwards towards the perineal defect with the perforator as pivot point. The free border of the inverted thick de-epithelised gluteal dermis is then secured to the cut edges of the pelvic muscles acting as an autologous dermal vascularized substitute for the excised muscular pelvic floor whereas the gluteal subcutaneous tissue is used to fill the pelvic dead space. The overlying gluteal skin on both buttocks is advanced by undermining supra-fascially over the gluteal muscles and closed in layers.

Results

Surgical time for the combined reconstruction was 69 minutes. There was no flap loss, no wound complications, no perineal pain or perineal hernia during a 28-month follow-up. The patient resumed normal sexual activity 6 months post-operatively.

Conclusion

The extended version of the PTO flap allows functional restoration of the vagina. It involves minimal dissection, can be performed in prone position and recreates the natal cleft. Its dermal component replaces the excised muscular pelvic floor preventing from perineal hernias, whereas its subcutaneous component obliterates dead space with no donor site morbidity. The versatility of the PTO flap and its extension can be utilised in the reconstruction of other perineal defects.  

 

1. Wagstaff, M. J. D et al. (2009) Perineal and posterior vaginal wall reconstruction with superior and inferior gluteal artery perforator flaps. Microsurgery, 29: 626–629.
2. Chasapi, M.Maher, P.Mitchell, M.Dalal “ The Perineal Turn Over (PTO) perforator flap”: A new and simple technique for perineal reconstruction after Extralevator Abdominoperineal Excision (ELAPE). Ann Plast Surg.2017 Nov 21.