Study for Clinical Efficacy of Sleep Surgery in Treatment of Patients with Moderate-Severe Obstructive Sleep Apnea

BACKGROUND AND OBJECTIVES: Surgical treatment is considered as a secondary treatment option for obstructive sleep apnea (OSA). This study was performed to determine whether surgical treatment can be considered in patients with moderate-severe OSA as a treatment modality. MATERIALS AND METHODS: A total of 127 patients with moderate-severe OSA were retrospectively enrolled. The anatomic narrowing sites were mainly evaluated using cephalometry and drug induced sleep endoscopy (DISE), and then multi-level surgeries were performed. RESULTS: Both uvula and soft palate were the most frequent narrowing sites and a total of 110 patients showed upper airway narrowing more than two anatomic structures. A total of 79 patients (62.1%) were categorized as responders and 48 patients (39.1%) were non-responders. After multi-level sleep surgeries, patients' subjective symptoms and sleep parameters were significantly improved. However, AHI was not considerably decreased. Non-responders to sleep surgeries showed relatively higher rates of severe OSA and body mass index. Tongue base narrowing, incomplete corrections of nasal pathologies and soft palate were significant factors for lower success rates. CONCLUSION: We estimate that sleep surgery might be a therapeutic option for moderate to severe patients with OSA. A delicate pre-operative evaluation for upper airway narrowing is necessary to adapt sleep surgery to these patients.

Should the High Septal Deviation be Corrected to Improve Nasal Obstruction During Septal Surgery?

BACKGROUND AND OBJECTIVES: High dorsal deflection of the nasal septum around cartilage or the perpendicular plate is technically difficult to correct. The objective of this study was to assess whether correction of high septal deviation during septoplasty is necessary to improve nasal airflow. PATIENTS AND SURGICAL METHOD: Twenty-one patients with high septal deviation around the septal cartilage or the perpendicular plate were included in this study. In order to improve nasal obstruction, septoturbinoplasty was performed, but high septal deviation was not corrected. Subjective and objective improvements were evaluated using the visual analogue scale and acoustic rhinometry 1 month before and 3 months after surgery. RESULTS: After correction of nasal septum deviation except high septal deviation and reduction of turbinate mucosal volume, postoperative nasal volume and minimum cross-sectional area were significantly increased. Subjective symptom scales for nasal obstruction, rhinorrhea, sneezing, and posterior nasal drip were considerably improved after limited septoturbinoplasty in patients who still had high dorsal deflection of the nasal septum. CONCLUSION: Our findings suggest that limited septoturbinoplasty without excessive resection of high dorsal deflection of the nasal septum can improve nasal airflow and reduce subjective symptoms, including nasal obstruction.

The Effect of Cryoprotectants on the Survival Rate of Human Frozen Thawed Erythrocytes / 대한수혈학회지

BACKGROUND: This study was carried out to determine the effect of the kinds and concentration of cryoprotectants and freezing temperature on the survival rate of frozen erythrocytes. METHODS: Erythrocytes mixed with three different concentrations of amylopectin, k-carrageenan, dextran and hydroxyethylstarch as cryoprotectants were frozen at -10, -30, -50 and -196degrees, respectively, and thawed at 35degrees. The survival rate of frozen erythrocytes was determined by hemoglobin concentration of supernatant of thawed erythrocytes. Morphological changes were observed by scanning electron microscopy. RESULTS: Frozen erythrocytes with amylopectin or k-carrageenan showed relatively low survival rate (<40%). In case of erythrocytes with dextran, the survival rate of erythrocytes with 30% dextran showed significantly increased survival rate compared with 20% or 25% dextran (p<0.05). The survival rates of erythrocytes with 30% dextran and freezing temperature of -10degrees, -50degrees and -196degrees showed 80.44%, 73.61% and 88.84%, respectively. Frozen erythrocytes with hydroxyethylstarch showed significantly high survival rate with freezing temperature of -196degrees (hydroxyethylstarch conc. 20%: survival rate 66.26%, 25%: 64.51%, 30%: 86.22%) compared with other freezing temperature. Most of frozen erythrocytes with amylopectin of k-carrageenan were changed to spherocytes by freezing process. The change to echinocytes of erythrocytes with dextran was decreased according to the increasing concentration of dextran. The change to stomatocytes of erythrocytes with hydroxyethylstarch was decreased according to the increasing concentration of dextran. CONCLUSION: It was found that the kinds and concetration of cryoprotectants and freezing temperature affected the survival rate and morphological change of erythrocytes. Dextran or hydroxyethylstarch could increase the survival rate of frozen erythrocytes over 80% by protection of erythrocytes from the physical, chemical stress during freezing process.