Head-Down Tilt Lithotomy Position and Well-Leg Compartment Syndrome in Minimally Invasive Abdominopelvic Surgery

Abstract

Minimally invasive surgery (laparoscopy and robotic-assisted surgery) has become the standard of treatment for many abdominopelvic surgical conditions, offering substantial benefits for patients and healthcare systems. These approaches, however, frequently require the use of extreme non-physiological patient positioning, specifically, the head‑down tilt lithotomy (HDTL) or Lloyd-Davies position. Introduced in 1939, this positioning technique was widely embraced within the surgical community as it facilitates simultaneous exposure of the pelvis and perineum and improves operative access. Nevertheless, the widespread adoption of prolonged HDTL positioning has introduced unique perioperative risks, including well‑leg compartment syndrome (WLCS), a rare but potentially devastating complication caused by sustained lower‑limb hypoperfusion and subsequent ischaemia–reperfusion injury. Despite its severity, WLCS remains poorly recognised among clinicians, with preventive practices that are inconsistently applied, poorly standardised, and largely informed by limited empirical evidence. As minimally invasive surgery becomes increasingly ubiquitous, there is concern that the use of steeper HDTL angles for longer intraoperative durations and in more complex surgical scenarios may result in an increased incidence of WLCS.
This thesis aimed to address critical gaps in understanding the incidence, prevention, and physiological mechanisms underlying WLCS during prolonged minimally invasive abdominopelvic surgery. A multi‑phase research programme was undertaken, comprising three complementary studies. First, a global clinician survey examined contemporary HDTL-related perioperative practices, clinician awareness and perceptions, and reported experiences of WLCS. Second, an international, multi-specialty Delphi consensus study was xviii conducted to establish expert‑driven recommendations for perioperative WLCS prevention and management. Third, a prospective intraoperative observational study evaluated lower‑limb perfusion, muscle and cerebral oxygenation, microvascular function, and circulating biomarkers of inflammation and nitric oxide bioactivity during prolonged HDTL positioning.
A total of 595 clinicians from 71 countries across 14 surgical and perioperative specialties participated in the survey. The findings revealed marked variability in practice, limited awareness of WLCS, and a strong reliance on experience‑based rather than evidence‑based preventive strategies. One in five respondents (20.5%) reported encountering at least one case of WLCS in their career, with a total of 170 cases described. Prior personal experience of WLCS strongly influenced clinician attitudes and perioperative behaviour, while duration of uninterrupted head‑down tilt emerged as a key predictor of reported cases.
The Delphi study comprised three iterative rounds involving 91 participants from 29 countries across five stakeholder groups. Consensus was achieved across several core areas, including clinical awareness and staff education, patient risk assessment, positioning strategies, leg‑rest intervals, and postoperative vigilance, while highlighting ongoing uncertainty and priority research needs in areas such as mechanical thromboprophylaxis and informed consent. The process yielded 26 best‑practice recommendations, which informed the development of an exemplar standard operating procedure designed to facilitate implementation of the recommendations at institutional levels.
The physiological study involved 25 patients undergoing robotic‑assisted colorectal surgery in prolonged (>60 minutes) HDTL positioning. The study demonstrated sustained lower‑limb hypoperfusion, progressive impairment of muscle microvascular reperfusion, and early depletion of nitric oxide biomarkers during prolonged HDTL, with clinically meaningful physiological deterioration occurring within approximately two hours of uninterrupted head-down tilt.
Collectively, these findings demonstrate that WLCS is a preventable complication driven by modifiable intraoperative factors and influenced by inconsistent perioperative practice and limited clinical awareness. This thesis provides an integrated, multidisciplinary evidence base to inform standardised preventive strategies and support safer implementation of minimally invasive abdominopelvic surgery.

Date of Award	29 Jun 2026
Original language	English
Awarding Institution	University of Portsmouth
Supervisor	Maria Perissiou (Supervisor), Ant Shepherd (Supervisor) & Zoe Saynor (Supervisor)