Reconstruction of the trachea.

This article reviews established methods of autologous tracheal reconstruction, the various synthetic prostheses that have been used in clinical practice, and briefly describes the latest developments in stem cell tracheal bioengineering and allogeneic tracheal transplantation. Reconstruction of the trachea is challenging due to its part cervical part thoracic location, proximity to major vessels, variable blood supply, and its constant colonization with bacteria. In cases of limited resection, primary anastomosis, autologous patch grafts, local advancement rotation flaps, and locoregional cutaneous and muscle flaps will often suffice. In more extensive resections, complex composite microsurgical reconstruction with a radial forearm free flap with cartilage grafts for skeletal support has proven to be viable and reliable. Synthetic tracheal prostheses, solid as well as porous, have been trialed with disappointing results. Infection, dislodgement, migration, and obstruction are not uncommon. Reconstruction with the cadaveric tracheal allografts and aortic allografts continue to be fraught with complications, specifically graft infections. Tracheal bioengineering and tracheal allotransplantation have emerged relatively recently. Despite early promising results, long-term outcome data on these new techniques are still lacking.

Reconstruction of the (Crico)trachea for malignancy in the virgin and irradiated neck.

BACKGROUND: Reconstruction of the trachea following resection for malignancy is challenging. We present our experience over a 5-year period, and a reconstruction algorithm with particular emphasis on minimising complications associated with radiotherapy. METHODS: A maximum of six tracheal rings can be resected and anastomosed primarily with acceptable tension. A more conservative approach is required in an irradiated trachea. For a limited defect localised anteriorly or laterally, a tracheal flap can be fashioned. As for more eccentric defects, an option is to convert the defect into an asymmetrical segmental defect, and to primarily anastomose the trachea with rotation of the distal stump. Our workhorse loco-regional flaps for patch reconstruction or suture line reinforcement include the sternocleidomastoid, internal mammary artery perforator and pectoralis major myocutaneous flaps. For extensive defects, a radial forearm free flap (RFFF) with rib cartilage struts for rigidity provides a good solution. RESULTS: Fifteen patients (M:F = 4:11, median age 69 years) were identified. Six cases were locally aggressive papillary thyroid cancer. Mean follow-up was 17 months. Five and two patients had had radiotherapy prior to and following tracheal resection, respectively. Nine patients were extubated at the end of surgery, two were successfully decannulated from their T tube subsequently, and one from his tracheostomy. The two surgical complications included a partial RFFF dehiscence causing minor air leak, and major haemorrhage that warranted urgent operation and pectoralis major flap reconstruction. CONCLUSION: Reconstruction of the trachea requires individualised techniques suited to the patient's body habitus, co-morbidity, previous treatment and the configuration of the defect.

Randomized double-blind crossover study to determine the effects of erythromycin on small intestinal nutrient absorption and transit in the critically ill.

BACKGROUND: The gastrokinetic drug erythromycin is commonly administered to critically ill patients during intragastric feeding to augment small intestinal nutrient delivery. However, erythromycin has been reported to increase the prevalence of diarrhea, which may reflect reduced absorption and/or accelerated small intestinal transit. OBJECTIVE: The objective was to evaluate the effects of intravenous erythromycin on small intestinal nutrient absorption and transit in the critically ill. DESIGN: On consecutive days, erythromycin (200 mg in 20 mL 0.9% saline) or placebo (20 mL 0.9% saline) were infused intravenously between -20 and 0 min in a randomized, blinded, crossover fashion. Between 0 and 30 min, a liquid nutrient containing 3-O-methylglucose (3-OMG), [13C]triolein, and [(99m)Tc]sulfur colloid was administered directly into the small intestine at 2 kcal/min. Serum 3-OMG concentrations and exhaled (13)CO2 (indices of glucose and lipid absorption, respectively) were measured. Cecal arrival of the infused nutrient was determined by scintigraphy. Data are medians (ranges) and were analyzed by using Wilcoxon's signed-rank test. RESULTS: Thirty-two mechanically ventilated patients were studied. Erythromycin increased small intestinal glucose absorption [3-OMG AUC360: 105.2 (28.9-157.0) for erythromycin compared with 91.8 (51.4-147.9) mmol/L · min for placebo; P = 0.029] but tended to reduce lipid absorption [cumulative percentage dose (13)CO2 recovered: 10.4 (0-90.6) compared with 22.6 (0-100) %; P = 0.06]. A trend to slower transit was observed after erythromycin [300 (39-360) compared with 228 (33-360) min; P = 0.07]. CONCLUSIONS: Acute administration of erythromycin increases small intestinal glucose absorption in the critically ill, but there was a tendency for the drug to reduce small intestinal lipid absorption and slow transit. These observations have implications for the use of erythromycin as a gastrokinetic drug in the critically ill. This trial was registered in the Australian New Zealand Clinical Trials Registry as ACTRN 12610000615088.