Soo-Jong Choi

Endoscopic transnasal approach for the treatment of isolated medial orbital blow-out fractures: a prospective study of preoperative and postoperative orbital volume change.

Endoscopic transnasal reduction is a safe and effective technique for the treatment of blow-out fractures of the medial orbital wall. However, because this approach does not use rigid permanent material for reconstruction of the fractured medial orbital wall, some degree of herniation of the orbital contents may occur after the intraethmoidal packing material is removed. The purpose of this study was to evaluate the change in orbital volume in patients with medial orbital wall fractures treated through an endoscopic transnasal approach. This study was a prospective analysis that includes 20 patients who underwent endoscopic transnasal reduction of medial orbital wall fractures between April 2007 and December 2008. Computer-assisted orbital volume measurements were made using axial computed tomography. The mean (standard deviation [SD]) volume increase was 2.00 (0.92) cm3 and the mean (SD) dimension of the fractured orbital wall was 2.76 (0.83) cm2. After endoscopic surgery, an average (SD) volume decrease of 2.15 (0.91) cm3 was achieved with ethmoid sinus packing. After removal of the packing materials, 1.14 (0.78) cm3 increase of the orbital volume was observed. The dimension of the orbital wall fracture significantly correlated with the increased preoperative orbital volume (P = 0.002, r = 0.609); the preoperative increase in the orbital volume also significantly correlated with volume relapse after removal of the packing (P = 0.023, r = 0.452). These findings suggest that in broad orbital wall fractures, reconstruction of the orbital wall by rigid materials or prolongation of the packing period should be considered, because orbital volume can increase again after packing removal, and may thus lead to postoperative complications.

Objective preoperative estimation of the ability of primary closure on anterolateral thigh free flap donor site: circumference and area ratios of deep tissue to thigh.

Purpose: The purpose of this study was to consider the relationship between the ratio of deep tissue including muscle to thigh at donor sites and the possibility of performing primary closure of donor site. Methods: The subjects were 74 patients who had harvesting of anterolateral thigh (ALT) free flap from June 2005 to June 2011. Primary closure was possible for 65 but not possible for 9. All received CT angiography of lower extremity before their operations. We measured circumference and cross‐sectional area of thigh and deep tissue including muscle at the reference point. Using the measured data, we examined the ratio of circumference as well as cross‐sectional area of deep tissue including muscles to thighs. Results: For whom primary closure was possible, the ratio of deep tissue including muscles circumference to thighs at the reference point was 0.83 ± 0.07 on average, and the ratio of cross‐sectional area was 0.68 ± 0.11. For whom primary closure was not possible, the ratio of circumference was 0.89 ± 0.06 on average, and the cross‐section areas was 0.8 ± 0.07. The average width of flap for those with primary closure was 64.9 mm and without primary closure was 84.4 mm. There was statistical significance in ratios of circumference and cross‐sectional area between primary closure and without primary closure. Conclusion: Primary closure of donor site when performing ALT free flap gets increasingly difficult as the ratio of deep tissue including muscle in the thighs increased. Such information prior to the procedure will be helpful in determining flap design and finalizing the operation plan.

Extent of palatal lengthening after cleft palate repair as a contributing factor to the speech outcome.

AbstractOperative techniques in performing cleft palate repair have gradually evolved to achieve better speech ability with its main focus on palatal lengthening and accurate approximation of the velar musculature. The authors doubted whether the extent of palatal lengthening would be directly proportional to the speech outcome. Patients with incomplete cleft palates who went into surgery before 18 months of age were intended for this study. Cases with associated syndromes, mental retardation, hearing loss, or presence of postoperative complications were excluded from the analysis. Palatal length was measured by the authors’ devised method before and immediately after the cleft palate repair. Postoperative speech outcome was evaluated around 4 years by a definite pronunciation scoring system. Statistical analysis was carried out between the extent of palatal lengthening and the postoperative pronunciation score by Spearman correlation coefficient method. However, the authors could not find any significant correlation. Although the need for additional research on other variables affecting speech outcome is unequivocal, we carefully conclude that other intraoperative constituents such as accurate reapproximation of the velar musculature should be emphasized more in cleft palate repair rather than palatal lengthening itself.

Role of protein kinase Cµ isoform expression in dimethylhydrazine-induced vascular endothelial proliferation

1,2-Dimethylthdrazine (DMH) has been known to induce vascular neoplasms, such as malignant endothelioma, in animal experiments through the induction of abnormal proliferation of human umbilical vein endothelial cells (HUVECs). We studied the effect of protein kinase C (PKC) isoforms on DMH-induced abnormal proliferation of vascular endothelium to identify the isoforms with higher relevance. The study was conducted with pure culture HUVECs in a control group and a 1x10-9 M DMH-treated group. The mRNA and protein expression of PKC isoforms in DMH-treated HUVECs was evaluated by reverse transcription-polymerase chain reaction and western blotting. DMH-induced PKC production was detected by a PKC activity assay. To investigate the role of the PKC isoforms in DMH-induced abnormal HUVEC proliferation, we modulated PKCµ expression in DMH-treated HUVECs using small interfering RNA. We determined the expression of 11 PKC isoforms by PCR analysis in both the control and DMH-treated groups, and the results were statistically analyzed to detect any differences. According to the results, both groups expressed 6 out of 11 isoforms. Expression of PKCµ was significant in the DMH-treated group, and downregulation of PKCµ inhibited DMH-induced abnormal HUVEC proliferation. The PKCµ isoform is believed to be important in the abnormal growth of vascular endothelial cells induced by DMH, and this was confirmed by an objective siRNA experiment, which showed a clear decrease in PKCµ expression. Therefore, it is believed that PKCµ is a key factor in the abnormal proliferation of vascular endothelial cells, and these results can be used as fundamental research data for abnormal vessel development or the embryologic mechanisms of vessel development.

Iatrogenic nasal vestibular stenosis after maxillofacial reconstructive surgery

Nasal vestibular stenosis is not only an esthetic, but also a functional problem for the patient. It is caused by disruption of the nasal vestibular lining with secondary proliferation of granulation and fibrous tissue. Various causes account for the development of nasal vestibular stenosis, including trauma, infection, and iatrogenic injury to the vestibular skin. Although a number of techniques have been described for repairing vestibular stenosis, correction may be difficult because of the tendency to wound contracture and recurrence. Herein, we describe a rare clinical presentation of nasal vestibular stenosis after maxillofacial surgery, which was successfully treated with endoscopic lysis of synechiae, release of vestibular scarring, and nasal stenting. This study was approved by the institutional review board of Pusan National University Hospital.