Influence of the early postoperative thyroid hormone level and the non-thyroidal illness syndrome on wound healing and anastomotic healing after visceral surgery

Wound healing disorder (WHD) and anastomotic leakage (AL) are still two of the most common complications after visceral surgery although several factors influencing their occurrence have been revealed. They contribute to rising costs for the health care system and compromise patient’s physical and psychological condition, thereby increasing morbidity and mortality. There are indications that hormone abnormalities of the thyroid gland could impair wound healing as well as anastomotic healing yet information about thyroid hormone level (THL) and their effect on postoperative complication rate are scarce. It was the goal of this study to evaluate the impact of early postoperative THL on the rate of WHD and AL on a broad study collective. Therefore 949 patients undergoing visceral surgery from 01/2008 to 07/2012 who were postoperatively treated in the intensive care unit and whose THL (fT3, fT4, TSH) was taken were retrospectively analysed. Information about impaired wound healing and anastomotic leakage was collected; anastomosis including biliodigestive anastomosis, enteroanastomosis as well as gastric and esophageal anastomosis. Patients with AL in the first two days after surgery were excluded in the assumption of a technical error. Also patients BMI, pre-existing Diabetes, cardiovascular and pulmonal disease, immunosuppressive and/or steroid medication, operation duration, operation urgency (emergent vs. elective), preoperative sepsis or hemodynamic instability, intraoperative supplementation of erythrocyte concentrates and nicotine consumption were noted. Binary logistic regression was performed to identify significant predictors of AL and WHD. Significant Variables in multivariate analysis were further assessed in univariate analyses. Out of 949 patients 206 (21,7 %) had impaired wound healing postoperatively with fT3-level, nicotine consumption, operation duration and operation urgency being an independent risk factor. 58 out of 590 patients (9,8 %) with intestinal anastomosis suffered from anastomotic leakage postoperatively. Thyroid hormone status and operation urgency were independent risk factors for the occurrence of AL. Hypothyroid patients and patients in the state of non-thyroidal illness (NTIS) had a significantly higher risk of developing AL then patients without hormone deviation, whereas patients undergoing emergent surgery had a lower incidence of AL compared to patients with elective surgery. Emergent surgeries as well as nicotine consumption had a higher incidence of WHD, the latter not being significant. Operation duration was longer in the group of patients with WHD then in non-WHD. 95 of 348 (27,3 %) patients with low fT3-level developed WHST compared to 107 out of 584 (18,3 %) with normal fT3- level. The present study supports the thesis that deficiency and deviation of thyroid hormones have an impact on wound- and anastomotic healing. Whether the deviation is cause or consequence of the complication should be the subject of further research. Nevertheless caution is required when dealing with patients whose laboratory parameters show signs of hypothyroidism, NTIS or merely low fT3 levels.2015-11-1