Case 2 (2024): Perforator-based soft tissue reconstruction around the knee, utilizing a D-POP ALT flap

Abdullah Najib Maalouf; Peter Sinkjær Kenney

Journal of Plastic, Breast & Reconstructive Surgery·Peer-reviewed, open-access surgical case reportsPeer-reviewed · Open access

Case 2 (2024): Perforator-based soft tissue reconstruction around the knee, utilizing a D-POP ALT flap · JPBRS

Case report

Case 2 (2024): Perforator-based soft tissue reconstruction around the knee, utilizing a D-POP ALT flap

Abdullah Najib Maalouf¹, Peter Sinkjær Kenney¹

¹Vejle Sygehus & Aarhus University Hospital, Denmark

Published March 31, 2024813 views5 min read

Distal ALT perforatorPropeller flapMalignant melanomaD-POP-flap

Export:RIS BibTeX

Abstract

A 73-year-old woman presented with malignant melanoma (pT2b-tumour) on her left thigh, located approximately 10 cm above the knee. The excision procedure aimed to remove the melanoma with a margin of 20 mm and perform sentinel node biopsy according to the protocols from Danish Melanoma Group (DMG). The patient had chronic obstructive lung disease, hypertension, hypercholesterolemia, ulcerative col

Key learning points

Pearls

The technique is simple, dependable and fairly straightforward.
The technique ensures high-quality and cost-effective reconstruction while upholding function and aesthetics.
The D-POP technique minimizes the risk for venous congestion due to its anterograde flow.
A perforator based approach should be more reliable compared with a random flap design.
Large flaps can be done, without sacrificing the main ALT pedicle, which can be used later if required.

Pitfalls

Thickness of the flap – can give a bulky appearance
Careful identification of a pivot point for the flap in order to ensure complete rotation
The perforator exhibits an uncommon yet well-recognized possibility of anatomical variation, which can pose challenges during flap harvesting. Intraseptal or intramuscular dissection can be carried out depending on the location of the perforator, here it was unnecessary.
For medially-based knee defects a D-POP ALT may not be optimal due to the distance from the pivot point. In these cases, a free-style flap based on a perforator from the superficial femoral artery along the sartorius muscle should be considered.

Patient history

Examination

The patient was seen in an outpatient setting first. She reported to have good general health and was self-reliant. The initial excision biopsy, performed in a dermatology setting with close margins, revealed a superficial spreading malignant melanoma with ulcerations but no presence of mitosis, margins were deemed clear. Adhering to the DMG-protocols, re-excision was planned to muscle fascia and a total margin of 20 mm. On examination, we found insufficient tissue for direct closure and due to functional considerations planned a flap reconstruction.

Pre-operative considerations

Soft tissue reconstruction in the knee region can be complex. Functionally, the aim is to restore natural mobility without any restrictions or contractions. Aesthetically, the aim is to adhere to the natural contours and achieve acceptable symmetry to the contra-lateral knee region. For functional reasons, skin-grafting is not deemed an optimal reconstructive approach as this may lead to contraction and restrictions in movement. Skin-grafting coupled with a local muscle flap, for example a gastrocnemius flap, can have untoward donor-site morbidity and a less than optimal aesthetic outcome. In more extensive cases, free flaps can be necessary, however these surgeries are not without risk for co-morbid elderly patients and also have an inherent risk of thrombosis or venous stasis. Local random flaps could be used; however, these would need significant size to be safe, especially given the patient’s active smoking status. For these reasons, a perforator-based approach was considered. A recently published case series described the use of a distal perforator-only propeller anterior lateral thigh flap (D-POP ALT) for reconstruction around the knee (1). This flap is based on the most distal perforator of the descending branch of the lateral circumflex femoral artery (LCFA). It is typically found 4-9 cm superior-lateral to the border of the patella pointing towards SIAS. In the case series, flap lengths of 25 cm and widths up to 6 cm were used. Pre-operatively, the surgeon (PSK) used Dupplex ultrasonography to identify the distal perforator. Dimensions of the flap were adjusted to ensure tension-free closure of the secondary defect, with the pivot point on the dopplered perforator. The patient was informed of the procedure, potential risks and the postoperative measures in order to best aid flap survival. Usually, the patients are discharged from the hospital on the same day. In some cases, the patient stays overnight if the flap requires close monitoring. The D-POP ALT flap both ensured satisfying reconstruction and minimal functional limitations, especially when we take the patient’s overall health status and smoking history into consideration.

References

Distal perforator-only propeller (D-POP) anterolateral thigh flap for reconstructions around the knee: 4-year experience, Damir Kosutic, Published:December 01. 2019DOI:https://doi.org/10.1016/j.bjps.2019.11.036
Bekarev M, Goch AM, Geller DS, Garfein ES. Distally based anterolateral thigh flap: an underutilized option for per- i-patellar wound coverage. Strat Trauma Limb Reconstr 2018;13(3):151–62.