Can immediate reconstruction with submandibular gland transposition broaden indications for transoral surgery for tonsillar cancer?

e18054

Background: Stratification based on pathologic parameters allows for reduced adjuvant radiotherapy in intermediate risk and observation alone for low risk oropharyngeal p16+ cancer (E3311 ECOG-ACRIN trial). Selection for transoral surgery (TOS), usually robotically assisted, for tonsillar cancers depends on the size and invasiveness of the primary tumor, involvement of adjacent parts such as the soft palate, proximity to external carotid artery branches, medial ipsilateral carotid artery that might be exposed with radical resection, and the likelihood of substantial communication between the oropharynx and internal neck structures. Postoperative recovery can be associated with substantial pain and dysphagia and a length of stay of > 5 days. There is a paucity of simple options for sealing the neck from the pharynx to prevent neck infection, exposure of larger vessels and salivary fistula, so large and deep tonsillar cancers are usually given chemoradiation. Larger surgical defects healing secondarily tend to require longer recoveries due to dysphagia and odynophagia. Methods: A prospective study of vascularized ipsilateral submandibular gland transposition flaps to primarily repair the surgical defect after TOS to resect previously untreated tonsillar cancers was performed from 2019 to 2022. A total of 19 patients underwent resection and repair. These included those with cancers extending to the soft palate (4) and medial position of internal carotid artery adjacent to the tumor (1). All had obvious communication between the neck and the pharynx after TOS, and had branches of the facial and external carotid arteries to the deep resection site ligated with neck dissection, prior to TOS. The submandibular gland flaps were sewn in place using robot assistance and hand. One patient had an extended flap with accompanying submental skin to repair the soft palate. Results: Partial dehiscence superiorly at the palate was the most common complication at 11%. None developed salivary fistulas or deep neck infections. Iatrogenic facial artery pedicle injury that was repaired occurred in one case. Oral intake was started at 1-3 days and length of stay averaged 5 days. There were no bleeding episodes at the TOS sites of cancer resection. All resections had clear margins. All submandibular gland flaps survived, with one patient having attached adipose tissue debrided in the office, healing uneventfully thereafter. Conclusions: The ability to primarily repair after resection of more extensive tonsillar cancers, that leave large communications between the pharynx and the neck, with a readily accessible and easy to harvest submandibular gland flap may change those previously selected for chemoradiation to be able to have TOS instead as initial treatment. This would allow for more pathological risk assessment of tonsil cancers and decreased adjuvant treatment when appropriate.

Microprocessor Control of the Spraying of Graded Coatings

A systematic study was made of the characteristics of a microprocessor controlled powder feeder in view of its utilization for the deposition of graded coating. The unit tested had the capability of feeding three different powders at rates which could be continuously varied up to about 40 g/min. MgOZrO2. was deposited on a stainless steel substrate using a series of thin (Ni/Cr)-Zirconia coats as intermediate layers. The results showed that such a technique could provide a valuable means of achieving a precise and effective control on the composition of the intermediate layers which can have important effects on the final quality of the deposit.