Hartmann’s procedures are commonly performed for left-sided colonic pathology in the emergency setting. However, only a proportion of patients have their Hartmann’s reversed due to its complexity, poor patient functional status, and the associated incidence of postoperative complications. A previous study within this cohort of patients revealed a 25% of reversal rate [5]. Current methods of preoperative assessment have been limited in the identification of early postoperative outcomes [16]. Body composition has been shown to be useful in the prediction of early outcomes in patients having colorectal cancer surgery [2, 4, 13, 17, 18], but there is no current evidence to suggest that this can be used in the prediction of outcomes following Hartmann’s reversal (HR). There is evidence in the literature that patients with reduced muscle mass or density are associated with worse surgical outcomes [8, 18]. Targeted prehabilitation of patients with physiotherapy, exercise training and dietary optimisation has been shown to improve both short-term complications, including infection risk as well as long-term patient survival [19].
Our study identified that low skeletal muscle index (SMI) (sarcopenia) was associated with a greater incidence of surgical site infections (SSIs). Similar studies in colorectal cancer patients have found that sarcopenia was also associated with greater postoperative complications (17). Therefore, early identification of sarcopenic patients undergoing reversal who may benefit from prehabilitation programs may help to minimise postoperative complications and overall morbidity.
Almost a quarter of our patients (n = 12, 25.5%) undergoing Hartmann’s reversal had evidence of sarcopenic obesity. These patients were found to be older, and a significant proportion of them were also complicated by postoperative surgical site infections (n = 5, 62.5%). Other studies have similarly found that sarcopenic obesity was an independent risk factor for developing surgical site infections and was also associated with poor functional status and survival [8, 14].
The utility of a validated automated AI algorithm to identify these at-risk body composition phenotypes may allow clinicians to target appropriate therapy prior to placing at-risk patients towards Hartmann’s reversal surgery. We have shown that commonly measured body metrics such as weight, body mass index (BMI) or body surface area (BSA) failed to predict postoperative outcomes, highlighting the benefits of CT-based body composition measurement. Prehabilitation (tailored exercise, nutrition, and physiotherapy) has been shown to improve metabolic and physiological reserves within patients over a short period of time within the perioperative period. For example, studies have shown improvements in muscle function, even following a 4-week intervention which involved moderate-intensity aerobic and resistance exercise, dietary counselling, protein supplementation and anxiety reduction strategies [20].
Our study had several strengths and weaknesses. Only patients with pre-Hartmann’s reversal CT scans were included in this study, as reliance on historical imaging to measure body composition changes could be affected by factors during their emergency presentation. Although many studies do not report the time between imaging and operative management, our median time of 6 months could be comparatively longer than the 30-day and 3-month intervals reported in some studies [8, 9, 14]. Our AI algorithm was validated by human researchers trained in body composition measurement and had a high validity score, an average dice coefficient of 0.98. However, there is a current lack of international consensus on definitions for different body composition phenotypes and the thresholds used for their diagnosis were based on patient cohorts with different illnesses and were domicile outside of Australia. Other limitations of our study included the retrospective nature of our data, our limited sample size (due to the lack of CT scans in a third of patients) and the low incidence of postoperative complications; allowing adequate assessment of predominantly surgical site infections. However, no Australian study in the literature currently exists for Hartmann’s reversals for comparison. We noted that our recruited patients for this study were those who had CT scans prior to surgery for two reasons. These were either patients who had colon cancer, and therefore the scans were performed as part of their cancer surveillance program or those who required complex planning for their Hartmann’s reversal, e.g. presence of a co-incidental abdominal ventral hernia.