Decellularization of Trachea With Combined Techniques for Tissue-Engineered Trachea Transplantation

OBJECTIVES: The purpose of this study is to shorten the decellularization time of trachea by using combination of physical, chemical, and enzymatic techniques. METHODS: Approximately 3.5-cm-long tracheal segments from 42 New Zealand rabbits (3.5±0.5 kg) were separated into seven groups according to decellularization protocols. After decellularization, cellular regions, matrix and strength and endurance of the scaffold were followed up. RESULTS: DNA content in all groups was measured under 50 ng/mg and there was no significant difference for the glycosaminoglycan content between group 3 (lyophilization+deoxycholic acid+de-oxyribonuclease method) and control group (P=0.46). None of the decellularized groups was different than the normal trachea in tensile stress values (P>0.05). Glucose consumption and lactic acid levels measured from supernatants of all decellularized groups were close to group with cells only (76 mg/dL and 53 mg/L). CONCLUSION: Using combination methods may reduce exposure to chemicals, prevent the excessive influence of the matrix, and shorten the decellularization time.

The Anatomical Relationship Between Recurrent Laryngeal Nerve and First Tracheal Ring in Males and Females

OBJECTIVES: Despite the modern advances in thyroid surgery, recurrent laryngeal nerve (rln) paralysis is still a critical problem. In order to decrease the rate of this complication, rln anatomy has been studied intensively. In our study, we aimed to recognize the relationship of rln and landmarks of the first tracheal ring. METHODS: Eighty-six female and 18 male patients who were undergone total thyroidectomy were included in this study. Trachea vertical height (tvh), right recurrent laryngeal nerve height (rrh), left recurrent laryngeal nerve height (lrh), right recurrent laryngeal nerve to trachea anterior face median raphe distance (rrd), left recurrent laryngeal nerve to trachea anterior face median raphe distance (lrd), right recurrent laryngeal nerve respect to trachea ratio (rrtr), and left recurrent laryngeal nerve respect to trachea ratio (lrtr) parameters of all patients were measured and compared in males and females using independent t-test and measurements on both right and left sides were compared statistically without sex discrimination. RESULTS: There were no significant differences between groups in tvh, rrh, rrd, lrd, rrtr, and lrtr parameters. Lrh parameter was significantly higher in males than in females (P<0.04). Comparison of right and left sides revealed that lrh was significantly higher than rrh (P<0.001), lrd was significantly higher than rrd (P<0.001), and rrtr was significantly higher than lrtr (P<0.001). CONCLUSION: In this study, we have shown that in all cases the rln was located around the lower half of trachea vertical length and at this level left rln was located significantly deeper than the right side.

Differences of the Voice Parameters Between the Population of Different Hearing Tresholds: Findings by Using the Multi-Dimensional Voice Program

OBJECTIVES: To compare voice parameters in subjects with different hearing level. METHODS: The evaluation consisted of Multi-Dimensional Voice Program (MDVP) and electroglottography. Group 1 consisted of normal hearing subjects which is bilateral average hearing better than 25 decibels (dB) whereas group 2 consisted of patients who have bilateral average hearing between the 25 and 60 dB and group 3 consisted of patients who have bilateral average hearing between the 60 and 90 dB. The evaluations were performed on males and females separately. RESULTS: In female subjects, fundamental frequency (F0), absolute jitter, %jitter and soft phonation index (SPI) were significantly different between the group 1 and group 2. Also, we detected significant difference on maximum phonation time (MPT), fundamental frequency, absolute jitter and %jitter, and variable F0 (vF0) values between group 1 and group 3. Male subjects demonstrated significant difference between the group 1 and group 2 in MPT, absolute jitter, %jitter, vF0, and SPI parameters. Between the group 3 and group 1; differences in absolute jitter, %jitter, shimmer, %shimmer, vF0, and SPI were also significant. CONCLUSION: This study concluded that even mild to moderate hearing losses may affect voice patterns in adults and also females and males react differently to hearing loss in some parameters.