Page 57 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

HBOT and vascular regeneration in oral mucosal flaps
0.2 mg/kg), injected subcutaneously, to achieve sedation and anesthesia for
blood sampling, wound preparation, and microcirculation measurements.
After induction of anesthesia, baseline and consecutive whole blood counts
were determined from 1 mL of blood obtained at each time point from the
central auricular artery. After performing baseline and serial microvascular
imaging on the designated wound flap region of interest (ROI), anesthesia was antagonized with atipamezole (Antisedan®, Pfizer Animal Health BV, Capelle
aan den IJssel, The Netherlands; 1 mg/kg SC). All animals were subjected to
the same experimental procedures; weighing, anesthesia, blood sampling, 3 baseline capillary density measurements, surgical preparation of palatine
flap wound (only on the first day), immediate postoperative and prospective flap FCD assessments followed by reversal of anesthesia, and exposed in two separate groups for two weeks to either normobaric/normoxic conditions (control) or HBOT.
Surgical wound preparation
After performing preoperative (baseline) capillary density measurements, a split-thickness flap in the anterior hard palatine mucosa was raised in all animals; details describing the wound model and surgical procedure have been described elsewhere.14 Briefly, just posterior to the maxillary auxiliary incisors or “peg teeth”, a partial-thickness mucosal flap was prepared by creating a transverse incision, 1 mm thick, along the length of the caudal side of the fourth plical ridge with two lateral releasing incisions. The mucosal flap was raised, suspended for 30 min, rinsed intermittently with warm 37±1oC sterile 0.9% NaCl (saline) solution, repositioned, and subsequently closed primarily with 6-0 Ethilon monofilament non-resorbable sutures (Ethicon, Johnson & Johnson, Langhorne, Pennsylvania, USA) placed 1 mm medially from the left and the right flap corners. One week after wound preparation the sutures were removed. The same investigator (RH) performed all surgical procedures.
Hyperbaric oxygen therapy protocol
For two consecutive weeks, during weekdays (i.e. 10 days total) after the last clinical HBOT session in the evenings, the animals designated to receive a medical grade protocol for HBOT were transported to the Department of Hyperbaric Medicine. A specially designed stainless steel transport pushcart- container built with adjustable compartments to accommodate at least 6 rabbit-sized animals was constructed. Equipped with both oxygen in- and
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