Establishing a role for the oral microbiome in infectious complications following major oral cavity cancer surgery

Surgery forms the backbone of treatment for most locoregional or advanced oral cavity squamous cell carcinoma. Unfortunately, infectious complications (including orocutaneous fistulas) are common following such extensive surgery and can afflict over half of patients. These complications can lead to delays in adjuvant treatment, prolonged hospitalization, reconstructive failure, and decreased quality of life. The frequency and morbidity associated with infectious complications has led to the search for pre-disposing risk factors; and, several have been identified, including both patient (e.g. diabetes) and surgical (e.g. operative time) factors. However, these findings are inconsistently reproduced, and risk factor modification has had a limited impact on rates of infectious complications. This is striking given that the likely contaminant-the oral microbiome-is a well-studied microbial reservoir. Because many oral cavity cancer surgeries involve violation of oral mucosa and the spillage of the oral microbiome into normally sterile areas (e.g. the neck), variance in oral microbiome composition and function could underly differences in infectious complications. The goal of this perspective is to highlight 1) this knowledge gap and 2) opportunities for studies in this domain. The implication of this line of thought is that the identification of oral microbial dysbiosis in patients undergoing surgery for oral cavity cancer could lead to targeted pre-operative therapeutic interventions, decreased infectious complications, and improved patient outcomes.

Impact of dental state and surgical factors on postoperative neck infection in oral cancer patients

Postoperative neck infection (PONI) is a known complication of neck dissection. In this study we explored the impact of dental status on the development of PONI, using orthopantomograms to assess edentulism, periodontal health, and caries status. Retrospective analysis was performed for all new oral cancer patients who had neck dissection between January 2008 and January 2020 in a tertiary head and neck centre. PONI risk factors assessed included patient characteristics, dental status, tumour, and surgical factors. Development of PONI was the primary outcome. Edentulous patients had lower risk of PONI (OR 0.06, p = 0.026) compared to those with 21 or more teeth. Periodontitis and dental caries were not statistically significant. Current smokers (OR 2.09, p = 0.044) and free flap reconstruction (OR 5.41, p < 0.001) were also significant predictors for development of PONI. This study highlights the presence of teeth as a potential source of infection post neck dissection and that orthopantomogram assessment may be inadequate to identify at risk patients. Future studies are required on direct clinical assessment of dentition to evaluate the impact of dental optimisation in prevention of PONI.

Investigation of Surgical Site Infections and Bacteria Detected Following Neck Dissection in Patients with Oral Cancer

During dissection for oral cancer, there is a high probability of bacteria indigenous to the oral cavity migrating to the surgical field in the neck due to the opening of new pathways of communication with the oral cavity. The risk of postoperative surgical site infection (SSI) in such patients is high due to malnutrition arising from perioperative eating disorders and dysphagia. Neck infections after neck dissection in oral cancer patients were investigated to elucidate the development of SSIs and their relationship with the results of bacterial culture.A total of 86 patients with oral squamous cell carcinoma who underwent neck dissection between January 2012 and December 2016 were enrolled. Ten factors were selected for investigation: (1) sex; (2) age; (3) primary site; (4) type of dissection; (5) whether or not there was a new pathway of communication between the oral cavity and the neck; (6) operative time; (7) blood loss; (8) number of drainage days; (9) amount of drainage at the time of drain removal; and (10) whether or not there was an SSI. Bacteria isolated from the catheter tip on drain removal were also investigated. Significant differences were observed between patients with and without SSIs (p-0.010) according to the presence of a new pathway of communication between the oral cavity and the neck (p-0.004); operative time (p-0.007); number of drainage days (p-0.029); or the amount of drainage at the time of drain removal. The present results indicate that selecting antibiotics appropriate to each patient and administering perioperative oral care are important in preventing SSIs.

Associations of Volume and Thyroidectomy Outcomes

Objective

This study explored how different hospital volumes and surgeon volumes affect thyroidectomy outcomes in terms of length of stay (LOS), costs, and in‐hospital mortality.

Data Sources

MEDLINE and EMBASE databases.

Review Methods

This study retrospectively analyzed a cohort of 125,037 thyroidectomy patients treated at Taiwan hospitals from 1996 to 2010. Relationships between hospital/surgeon volume and patient outcomes were retrospectively analyzed by propensity score matching. In conjunction with the retrospective study, a systematic review and meta‐analysis of the relevant literature also were performed.

Results

The mean LOS for all thyroidectomies performed during the study period was 3.3 days, and the mean cost was $1193.5. Both high‐volume hospitals and high‐volume surgeons were associated with significantly shorter LOS and lower costs compared with their low‐volume counterparts (P <. 001). Different volume groups had similar in‐hospital mortality rates. The meta‐analysis results consistently showed that the benefits of high‐volume hospitals/surgeons are reduced LOS and costs. However, low in‐hospital mortality rates were associated with high‐volume surgeons but not with high‐volume hospitals.

Conclusions

This meta‐analysis showed that patients who received thyroidectomies performed by high‐volume hospitals and surgeons had shorter LOS and lower costs compared with those treated by low‐volume hospitals and surgeons. In addition, in‐hospital survival rates were better in patients treated by high‐volume surgeons. Further research is needed to define the learning curve for thyroidectomy and to clarify how hospital volume and surgeon volume affect its success rate.