Skeletal muscle has remarkable regeneration capabilities, mainly due to its resident muscle stem cells (MuSCs). In this review, we introduce recently developed technologies and the mechanistic insights they provide to the understanding of MuSC biology, including the re-definition of quiescence and Galert states. Additionally, we present recent studies that link MuSC function with cellular heterogeneity, highlighting the complex regulation of self-renewal in regeneration, muscle disorders and aging. Finally, we discuss MuSC metabolism and its role, as well as the multifaceted regulation of MuSCs by their niche. The presented conceptual advances in the MuSC field impact on our general understanding of stem cells and their therapeutic use in regenerative medicine.

The reconstructive armamentarium of head and neck surgeons involved in hypopharyngeal and cervical esophagus reconstruction should encompass every option described herein in order to appropriately deal with specific clinical needs and patient requirements. However, fasciocutaneous free flaps (especially ALT) seem to play an ever greater role in restoration of pharyngoesophageal continuity.

Microvascular reconstruction in the elderly can be performed with high success rates, even though medical complications can occur more frequently compared to younger patients. Minor and major surgical complications in the elderly appear to be comparable to those in the younger population and do not affect final outcome or the perioperative mortality rate. Flap outcome does not seem to be significantly affected by age. Careful preoperative assessment and postoperative monitoring are mandatory to prevent adverse events, and prompt management is warranted whenever present.

Oral tongue and floor of mouth cancer needs to be classified according to a revised TNM staging system in which 'depth of infiltration' should be taken into account. An 'ideal cut off' for distinguishing 'low' (T1-T2) from 'high-risk' (T3-T4) categories has been proposed based on the literature review, but needs retrospective as well as large prospective trials before its validation.