Shifting Paradigms in Oral Cancer Reconstruction: Is the ALT Flap Replacing PMMC as the New Workhorse?

In the evolving field of head and neck surgical oncology, reconstruction following resection of oral cancers remains a critical challenge. Traditionally, the pectoralis major myocutaneous (PMMC) flap has been the workhorse for reconstructing large defects. However, in recent years, the anterolateral thigh (ALT) free flap has gained traction as a versatile and reliable alternative. This article explores whether the ALT flap is becoming the new workhorse in oral cancer reconstruction, discusses the factors driving this potential shift, and provides a perspective on clinical experiences from the field.

Historical Perspective: The PMMC Flap as the Traditional Workhorse

The PMMC flap has been a cornerstone in head and neck reconstruction since its introduction by Ariyan in 1979. This regional flap offers several advantages: it is reliable, technically straightforward, and does not require microvascular expertise, making it an excellent choice in settings where resources are limited.

The PMMC flap has been the go-to option for reconstructing defects following oral cancer resections, particularly in resource-constrained environments such as many parts of India. Its simplicity, robust blood supply, and ability to cover large defects make it an invaluable tool, especially in patients with limited donor site options or those unfit for prolonged surgeries.

Despite these strengths, the PMMC flap comes with limitations, particularly in terms of bulkiness, suboptimal aesthetic outcomes, and functional limitations in speech and swallowing. In a landscape where improving patient quality of life is becoming a central objective in oncology care, the search for better alternatives has driven interest in free flaps, most notably the ALT flap.

Emergence of the ALT Flap: A Versatile Alternative

The anterolateral thigh (ALT) flap, first introduced in 1984 by Song et al., has revolutionized the field of free tissue transfer in head and neck surgery. As a free flap, it requires microvascular anastomosis, making it more technically demanding than the PMMC. However, its versatility, adaptability to various defect sizes, and the ability to provide thin, pliable tissue make it an increasingly attractive option for oncologists and reconstructive surgeons alike.

Advantages of the ALT Flap in Oral Cancer Reconstruction

1. Thin, Pliable Tissue: Unlike the bulky PMMC flap, the ALT flap provides thin, pliable tissue that can be contoured more easily to fit the complex anatomy of the oral cavity. This leads to better functional outcomes in terms of speech, swallowing, and cosmesis.

2. Versatility: The ALT flap can be harvested with or without muscle, depending on the reconstruction needs. It can cover both small and large defects, making it adaptable for a wide range of cases, from minor resections to extensive composite defects.

3. Less Donor Site Morbidity: The donor site for the ALT flap is less conspicuous compared to the PMMC, leading to improved cosmetic outcomes and less functional impact on the donor site. Patients experience fewer functional impairments after ALT flap harvest, and the morbidity of the thigh donor site is minimal in most cases.

4. Improved Functionality: Because the ALT flap can be harvested with perforator vessels only, the resultant flap can be thin and provide better mucosal lining, enhancing the patient's ability to articulate speech and swallow more naturally than with bulkier regional flaps.

Clinical Evidence Supporting the Shift

Recent studies comparing the outcomes of PMMC and ALT flaps in oral cancer reconstruction have shed light on this potential shift. A retrospective study by Lin et al. (2017) found that patients who underwent ALT flap reconstruction had significantly better functional outcomes in terms of speech and swallowing when compared to those who received PMMC flaps. Additionally, the ALT flap group experienced fewer complications, particularly regarding donor site morbidity.

A study by Bianchi et al. (2015) also highlighted the growing preference for free flaps like ALT in high-volume cancer centres with access to microvascular expertise. The study found that free flaps provided superior aesthetic and functional outcomes compared to regional flaps, including PMMC. Specifically, the ALT flap was favoured due to its ability to provide large amounts of tissue without the excessive bulk that often hinders the PMMC flap's performance in intraoral reconstruction.

Adoption of ALT in Indian Clinical Practice: Trends and Challenges

In India, where head and neck cancer rates are among the highest globally, the ALT flap is increasingly becoming the preferred option in tertiary cancer centres with the resources and expertise for microvascular reconstruction. We have witnessed this shift first-hand. Over the past five years, we have increasingly relied on the ALT flap for oral cancer reconstructions, particularly in cases where cosmesis and functionality are primary concerns.

The adoption of the ALT flap in Indian practice, however, is not without challenges. The need for microsurgical expertise and the longer operating times required for free flap transfers are significant hurdles, particularly in smaller centres or regions with limited access to specialized training. Moreover, the costs associated with microvascular surgery can be prohibitive for many patients, especially in a country where access to affordable cancer care remains a significant issue.

Personal Experience: Using the ALT Flap at SSO Epic Cancer Centre

At SSO Epic Cancer Centre in Ahmedabad, the ALT flap has provided superior outcomes in terms of both aesthetics and functionality, especially in younger patients or those requiring extensive resections.

In cases where we have utilized the ALT flap, we have consistently observed better patient-reported quality-of-life scores compared to our historical cases with PMMC. Patients report less discomfort, better cosmesis, and improved swallowing and speech, aligning with global findings that favour the ALT flap for more complex reconstructions.

The Future of Flap Selection in Oral Cancer Reconstruction

As surgical oncology continues to advance, the shift from PMMC to ALT-free flap in oral cancer reconstruction reflects a broader trend towards personalized, patient-centred care. The increasing availability of microsurgical training in India, coupled with a growing body of evidence supporting the superior outcomes of free flaps, suggests that the ALT flap may indeed become the new workhorse for complex oral cancer reconstructions.

However, the decision between PMMC and ALT remains nuanced. In resource-limited settings or for patients who are not candidates for lengthy microsurgical procedures, the PMMC flap continues to play an essential role. The challenge lies in balancing the need for better functional and cosmetic outcomes with the practical realities of surgical expertise, infrastructure, and patient factors.

Conclusion

The potential shift from PMMC to ALT-free flap as the workhorse for oral cancer reconstruction marks an exciting evolution in head and neck surgery. While the PMMC flap has served its role well, particularly in resource-constrained environments, the ALT flap offers distinct advantages in terms of versatility, functionality, and patient quality of life. As microsurgical expertise becomes more widespread and cost barriers are addressed, the ALT flap is likely to take centre stage in oral cancer reconstruction, offering patients a more refined, personalized approach to care.

At SSO Epic Cancer Centre, our increasing reliance on the ALT flap reflects this broader shift, and our experience aligns with global trends favouring the superior outcomes of free flaps. Going forward, the key will be ensuring access to the necessary resources and training to bring these advances to all patients, regardless of geographic or economic constraints.