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Biomedical subjects

Chan Il Park

Publications and source records attributed to Chan Il Park.

15 recordsLinked to original sources
PubMed2006

Cervical sensory preservation during neck dissection.

Although the practice of neck dissection has greatly advanced from radical to function-preserving surgery, the impact of the sensory nerve-preserving neck surgery on the pain and quality of life (QOL) of patients has received little study. We evaluated neck morbidity and its impact on QOL associated with selective or modified radical neck dissection with or without preservation of cervical root branches. We conducted a retrospective cohort study comparing 24 patients who had their cervical root branches preserved to 29 patients whose root branches were removed during neck dissection. The spinal accessory nerve was preserved and sex, age, pathologic status, side and extent of neck dissection, and radiotherapy were comparable between groups. The groups were compared based on sensory and motor functions of the neck and shoulder and questionnaires on depression and QOL at follow-up of mean 18.7 (range 12-34) months after surgery. The nerve-preserved patients showed a low incidence and severity of neck and shoulder pain compared to the nerve-removed subjects (p<.05). Loss of sensation was more frequently experienced in the nerve-removed group on the earlobe and the lateral neck of the operated side (p<.05). Depression and QOL scores were higher in the nerve-removed group and significantly correlated with pain intensity. Preservation of the cervical root branches reduces postoperative pain as well as permanent anesthetic areas of the neck. This may also improve the mental state and QOL of patients undergoing neck dissection.

Adult↗
PubMed2006

Intraoperative parathyroid hormone assay for management of patients undergoing total thyroidectomy.

BACKGROUND: Rapid parathyroid hormone (PTH) assay has been applied to predict hypocalcemia after thyroidectomy compared with conventional close monitoring of serum calcium levels. We evaluated the reliability of intraoperative intact PTH (ioPTH) assay to predict hypocalcemia after total thyroidectomy and sought to develop an algorithm for the management of postthyroidectomy patients. METHODS: Rapid PTH assays were performed before and after thyroidectomy for 92 new patients receiving total thyroidectomy. Preoperative and postoperative serum calcium and standard PTH levels were serially obtained to 6 months after surgery RESULTS: Postoperative hypocalcemia developed in 34 of 92 patients (37%), who showed significantly lower ioPTH values compared with those of normocalcemic patients (mean 9.2 pg/mL vs 31.3 pg/mL). The ioPTH levels were significantly correlated with standard PTH levels (p < .001, r > 0.62), but not with early serum calcium levels within 8 hours after the operation. Sensitivity and specificity of ioPTH levels of <15.0 pg/mL for the prediction of postoperative hypocalcemia were 85% and 84%, respectively. A value of >15.0 pg/mL and <70% decline in ioPTH after thyroidectomy can reliably identify normocalcemic patients during thyroidectomy or patients requiring close monitoring and early calcium supplement CONCLUSIONS: Rapid ioPTH assay can reliably monitor parathyroid function after thyroidectomy and predict postoperative hypocalcemia. The proposed algorithm based on rapid PTH levels will lead to improved prediction of normocalcemic patients.

Adolescent↗
PubMed2006

Routine oral calcium and vitamin D supplements for prevention of hypocalcemia after total thyroidectomy.

BACKGROUND: The purpose of this study was to evaluate the clinical usefulness of routine oral calcium and vitamin D supplements in the prevention of hypocalcemia after total thyroidectomy. METHODS: Ninety patients who underwent total thyroidectomy were randomly assigned to routinely receive or not receive a supplement containing oral calcium (3 g/d) and vitamin D (1 g/d) for 2 weeks. Hypocalcemic signs and symptoms, serum calcium, and parathyroid hormone (PTH) levels were monitored and compared between the 2 groups. RESULTS: The incidences of symptomatic and laboratory hypocalcemia were significantly lower in the oral calcium/vitamin D group than in the group not receiving the supplement: 3 of 45 patients (7%) versus 11 of 45 (24%) and 6 of 45 (13%) versus 16 of 45 (36%), respectively (P < or = .02). The hypocalcemic symptoms were minimal in the supplement group but more severe in the group not receiving the supplement. Serum calcium levels decreased in both groups after surgery but recovered earlier in the supplement group. No hypercalcemia or PTH inhibition developed in the supplement group. CONCLUSION: Routine administration of a supplement containing oral calcium and vitamin D is effective in reducing the incidence and severity of hypocalcemia after total thyroidectomy.

Adolescent↗
PubMed2006

Removal of nonthyroidal neck masses with improved cosmetic outcomes in skin-lifting surgery.

OBJECTIVE: To evaluate the cosmetic benefit of neck skin-lifting surgery for the removal of nonthyroidal neck masses. STUDY DESIGN AND SETTING: Fifty patients with neck masses were divided into the following 2 surgical groups that were matched in age, sex, and the size, location, and pathology of lesions: skin lifting (n = 25) and conventional (n = 25). The operation time, hospital stay, complications, and subjective satisfaction with the incision scar as assessed on a visual analogue scale (VAS) were compared between the 2 groups. RESULTS: All but 2 lesions (lymphomas) were benign and were removed completely, drained, or biopsied. The surgery time, hospital stay, and complication rates did not differ significantly between the groups. The mean satisfaction score of the patients was 8.2 +/- 1.1 in the skin-lifting surgery group and 4.8 +/- 2.5 in the controls (P < 0.001). The incision scars were commonly hidden by natural hair or collars in the patients who received skin-lifting surgery. CONCLUSION: This surgical technique can be safely applied to most benign masses in the entire neck excluding the thyroid region, especially in patients who prefer neck scars to be invisible. EBM RATING: B-2b.

Abscess↗
PubMed2006

Treatment of branchial cleft cyst with intracystic injection of OK-432.

CONCLUSIONS: The data suggest that branchial cleft cyst (BCC) can be primarily treated with OK-432 sclerotherapy and only the remaining lesions with excision. OBJECTIVES: To evaluate the effectiveness of sclerotherapy using OK-432 in the treatment of BCC. MATERIALS AND METHODS: We treated 12 BCC patients (3 males and 9 females; mean age 25 years) with OK-432 sclerotherapy at an outpatient clinic. The cystic fluids were aspirated and diagnosed by cytomorphology and DNA cytometric analysis to exclude malignancy. The fluid aspirated from the cyst was replaced with an equal volume of OK-432 solution. The sizes of cysts were measured and compared before and after injection. The remaining cysts were excised and histopathologically compared with the excised BCCs that had not been treated with OK-432. RESULTS: Seven of 12 patients (58%) showed a complete response after OK-432 injection, administered one to three times. Three patients (25%) had only partial response and two (17%) were stationary. Five patients with remaining lesions underwent excision. There was no difficulty in dissecting around the cysts and no increased morbidity during operation. None of the patients had evidence of recurrences or malignancies developing during the follow-up period (mean 21 months, range 17-26 months). There were no major side effects except fever after sclerotherapy.

Adolescent↗
PubMed2006

Can mitomycin C really prevent airway stenosis?

BACKGROUND/OBJECTIVES: Mitomycin C (MMC) is used in the prevention of upper airway stenosis. However, the efficacy of MMC is still debatable, and the potential complications of MMC use have been scarcely reported. We evaluated the efficacy and early complications of MMC in a wound model of the subglottis. STUDY DESIGN: A randomized animal study. METHODS: Sixty rabbits underwent a full-thickness injury to the posterior subglottis by diode laser. The animals were randomly assigned to three groups according to the different topical treatments of MMC 0.4 or 10 mg/mL or saline alone for 5 minutes. Animals were killed at 4 weeks, and gross and histologic findings were compared among different groups and 10 age-matched, non-wound, normal controls. RESULTS: Thirty-two of the 60 (53%) animals died mainly of acute airway obstruction by necrotic debris, sloughs on, or cartilage collapse of the unhealed posterior subglottis during early weeks after wounding, higher in the MMC-treated animals (67%) than in the wound controls (25%) (P = .007). This resulted from the significant delay of wound healing in the MMC-treated groups compared with the wound controls (P = .012). The degree of subglottic stenosis was comparable among different groups (P > .8), although collagen deposition was significantly lower in the MMC-treated groups compared with the untreated controls (P = .036). CONCLUSIONS: There was a significant risk of acute airway obstruction from delayed wound healing in rabbits that received subglottic laser wounding and MMC treatment. This risk should be considered in the use of MMC in clinical practice.

Airway Obstruction↗
PubMed2005

Effect of topical mitomycin C on the healing of surgical and laser wounds: a hint on clinical application.

OBJECTIVES: Mitomycin C (MMC) is used in otolaryngological surgery to reduce complications from postoperative scarring. However, the effects of MMC on wound healing at different doses and on different wound types have not been fully described. The aim of this study was to evaluate the effects of topical MMC at 2 different doses on the healing of surgical and laser wounds. STUDY DESIGN AND SETTING: This was a randomized study using 20 rabbits. Six full-thickness wounds were made by excision or laser vaporization on the flank skin. The wounds were randomly treated by topical MMC of 0.4 or 1.0 mg/mL or saline for 5 minutes. RESULTS: Re-epithelialization and contraction of the original wounds were significantly delayed by the use of MMC (P < 0.01). The delayed healing effect of MMC was more prominent in the laser wounds than in the excision wounds. MMC inhibited collagen deposition and fibroblast proliferation of wounds on histological analysis. The 2 different concentrations of MMC showed no difference in gross or histological wound healing characteristics. CONCLUSION: Our results showed that MMC delays the healing of wounds as a result of the inhibition of fibrosis, especially for laser wounds.

Administration, Topical↗
PubMed2005

Torsional wave experiments with a new magnetostrictive transducer configuration.

For the efficient long-range nondestructive structural health inspection of pipes, guided waves have become widely used. Among the various guided wave modes, the torsional wave is most preferred since its first branch is nondispersive. Our objective in this work is to develop a new magnetostrictive transducer configuration to transmit and receive torsional waves in cylindrical waveguides. The conventional magnetostrictive transducer for the generation and measurement of torsional waves consists of solenoid coils and a nickel strip bonded circumferentially to test pipes. The strip must be premagnetized by a permanent magnet before actual measurements. Because of the premagnetization, the transducer is not suitable for the long-term on-line monitoring of pipes buried underground. To avoid the cumbersome premagnetization and to improve the transduction efficiency, we propose a new transducer configuration using several pieces of nickel strips installed at 45 degrees with respect to the pipe axis. If a static bias magnetic field is also applied, the transducer output can be substantially increased. Several experiments were conducted to study the performance of the proposed transducer configuration. The proposed transducer configuration was also applied for damage detection in an aluminum pipe.

Journal Article↗
PubMed2004

Comparison of hydrocolonic sonograpy accuracy in preoperative staging between colon and rectal cancer.

AIM: To compare the accuracy of hydrocolonic sonography (HUS) in determining the depth of invasion (T stage) in colon and rectal cancer. METHODS: A total of 1 000-2 000 mL of saline was instilled per rectum using a system for barium enemas, and then ultrasonography was conducted by a SSA-270A (Toshiba Co, Japan) sonolayer unit with a 3.75 MHz for 17 patients with colon cancer and 13 patients with rectal cancer before operation. After operation, T stage in HUS was compared with postoperative histological findings. RESULTS: Overall, the accuracy of T stage was 70%. It was 88% in colon cancer and 46% in rectal cancer. In evaluating nodal state, the accuracy of HUS was low in both colon (71%) and rectal cancers (46%) compared with conventional CT or MRI. The overall accuracy of N staging was 60%. CONCLUSION: HUS is valuable to evaluate the depth of invasion in colon cancer, but is less valuable in rectal cancer. Because HUS is low-cost, noninvasive, and readily available at any place, this technique seems to be useful to determine the preoperative staging in colon cancer, but not in rectal cancer.

Adult↗
PubMed2003

[A case of duodenal adenocarcinoma arising from the heterotopic pancreas].

Heterotopic pancreas, defined as the presence of pancreatic tissue that lacks anatomic and vascular continuity with the pancreas proper, may be more likely to undergo malignant change. However, malignancy arising from heterotopic pancreas is rare. In Korea, only one case of adenocarcinoma arising from a gastric heterotopic pancreas has been reported. Recently, we experienced a case of duodenal carcinoma arising from heterotopic pancreas in a 64-year-old man. Endoscopic biopsy of the stenotic duodenum was positive for adenocarcinoma, and he underwent a pancreaticoduodenectomy with subtotal gastrectomy. Histologic examination of the resected specimen satisfied the proposed conditions that are necessary to prove that a malignancy arose from heterotopic pancreas. Despite an adjuvant chemotherapy, he died 10 months after surgery. Herein, we report a case of duodenal adenocarcinoma arising from heterotopic pancreas with a review of the relevant literature.

Adenocarcinoma↗
PubMed2002

A phase III randomized trial of combined chemoradiotherapy versus radiotherapy alone in locally advanced non-small-cell lung cancer.

A phase III randomized trial was conducted to investigate whether induction chemotherapy followed by radiation can influence survival as compared with radiation alone in unresectable, locally advanced non-small-cell lung cancer (LADNSCLC). A total of 101 patients with unresectable stage IIIA or IIIB NSCLC were enrolled. Patients were stratified by performance status, weight loss, histology and stage, and then randomized to receive combined chemoradiotherapy or radiotherapy alone. Radiotherapy was administered in 1.8 Gy to 2.0 Gy standard fractions daily 5 times weekly for a total dose of 60 Gy to 65 Gy. The combined group received induction of cisplatin, etoposide, and vinblastine (PEV) chemotherapy with cisplatin 20 mg/m2 on days 1 to 5, etoposide 100 mg/m2 on days 2 to 4, and vinblastine 6 mg/m2 on day 1, which wasrepeated every 3 weeks for 3 courses, after which time the patients underwent radiotherapy. Of 101 patients registered, 89 patients (43 combined, 46 radiotherapy alone) were eligible for analysis. The response rates for the combined and radiotherapy groups were 65% (28/43) and 70% (32/46), respectively. The median survival time (MST) showed a tendency to be more prolonged in the combined group than in the group receiving radiotherapy alone (13.8 vs. 8.5 months). The MST in patients with nonsquamous histology was strikingly prolonged in the combined group as compared with the radiotherapy group (14 vs. 3.6 months, p 0.027). Likewise, the MST in patients with stage IIIB was significantly prolonged in the combined group as compared with the radiotherapy group (11.1 vs. 7.2 months, p 0.045). Together, the MST of the high-risk group with nonsquamous or stage IIIB was significantly higher in the combined group than that seen in the radiotherapy group (11.6 vs. 8 months, p 0.046), whereas the MST of the low-risk group, defined as having both squamous histology and stage IIIA, was similar in the two treatment groups (18.3 vs. 20.8 months, p = 0.293). In conclusion, induction PEV chemotherapy plus radiotherapy is superior to radiotherapy alone in high-risk subsets of unresectable LAD-NSCLC and therapeutic strategy should be based on the identification of prognostic factors.

Adult↗
PubMed2002

Early histopathologic changes after lateral semicircular canal transection and occlusion in guinea pigs.

Occlusion of the semicircular canals has been used in otoneurologic and skull base surgeries with preservation of hearing. In order to understand the role of occlusion in hearing preservation, we observed early histopathologic changes of the lateral semicircular canal following transection and occlusion in guinea pigs. After surgery, the membranous endolymphatic canal was collapsed, and its torn ends were sealed by intramural bone dust in the bony semicircular canal. On the first postoperative day, the endolymphatic canal was expanded to its normal shape, and the sealing at the torn ends was maintained by the bone dust. These findings suggest that occlusion after semicircular canal injuries, by making blind ducts in the membranous endolymphatic canal, is important for the preservation of postoperative hearing.

Animals↗
PubMed2002

Histologic changes of pulmonary arteries in congenital heart disease with left-to-right shunt (part 1): correlated with preoperative pulmonary hemodynamics. Emphasizing the significance of pulmonary arterial concentration.

The hemodynamic findings related to the histologic changes in the small pulmonary arteries in congenital heart disease were analyzed with a left-to-right shunt. A lung biopsy was performed during the repair because of pulmonary arterial (PA) hypertension (mean PA pressure > or = 15 mmHg) in 38 patients. There were 13 patients whose age ranged from 2 years to 25 years old. A preoperative cardiac catheterization was performed to locate the site of the defect and to determine the preoperative hemodynamic findings. Among them, 29 patients had pulmonary vascular resistance (PVR) > 2.5 unit/m2. The lung biopsy specimens were investigated microscopically for the Heath- Edward grade, morphometric analysis of medial wall thickness (MWT) and the rate of the decrease in the pulmonary arteriolar concentration (PAC) obtained by the alvoelo-arterial ratio divided by patients' age. All patients were in the Heath-Edward grade I to III (29 patients in grade I). This grade correlated with the MWT, but did not correlate with a decrease in the PAC. The MWT and the rate of the decrease in the PAC did not accompany each other, but either one had the tendency dominate the pattern in individual patients. The MWT had a close correlation with the mean PA pressure and PVR, and an even closer correlation in patients with a high PVR and those older than 2 years of age. The rate of the decreased in the PAC showed a weak correlation with the shunt volume in patients over 2 years of age or with a large shunt. In the high flow group (PVR < 2.5 unit/m(2), Qp/Qs > 2.0, n=14) the MWT was significantly thinner and the rate of the decrease in the PAC was significantly higher than the high resistance group (PVR > 2.5 unit/m2, Qp/Qs2 < 2.0, n=13). The rate of the decrease in the PAC correlated with the patients' age, but the MWT did not. The lung biopsy results in patients who had both left-to-right shunts and pulmonary hypertension showed that the rate of the decrease in the PAC was weakly related to the shunt volume and the MWT was related to the PA pressure and PVR. Either an increased MWT or the rate of the decrease in the PAC tended to dominate. These phenomena were prominent in patients older than 2 in whom a wide range of individual variations were noted in the morphometric pattern. The medial hypertrophy and the rate of the decrease in the PAC may be induced by different stimuli or that medial hypertrophy may play a role in preventing PAC decrease.

Adolescent↗
PubMed2002

Histologic changes of pulmonary arteries in congenital heart disease with left-to-right shunt (part 2): emphasis on the significance of pulmonary arterial concentration in the correlation with pulmonary hemodynamics after repair Ed-- the above is an alternative title for your consideration.

We performed this study to assess the correlation of residual pulmonary hypertension in the immediate postoperative period with that in the late follow-up period, to assess the histologic changes of pulmonary arteries (PA) at the time of repair for patients with congenital heart disease consisting of left-to-right shunt, and to clarify the role of lung biopsy in determining the operability and reversibility of pulmonary vascular changes. Lung biopsy was performed during repair in 38 patients, with a wide range of age, who had congenital left to right shunt and pulmonary hypertension. All were Heath-Edward grade III or less. Morphometric study included measurement of medial wall thickness (MWT) and decrease rate of pulmonary arterial concentration (PAC). Mean PA pressure in the immediate postoperative period was measured in all 38 patients. Follow-up cardiac catheterization was performed in 15 patients (average 3.8 years after repair). At operation, 5 patients of this late follow-up group were under 2 years of age and the other 10 were 2 or more. During catheterization, pulmonary hemodynamic reaction was observed both under room air inhalation and after inhalation of hypoxic gas FiO2 0.15. Mean PA pressure and pulmonary vascular resistance (PVR) in the immediate postoperative period had a significant correlation with PA pressure and PVR values before the operation, but not with morphometry, Heath-Edward grade, or with pulmonary hemodynamics in late follow-up. During the late follow-up study, 5 of the 15 patients had pulmonary hypertension (defined as mean PA pressure > or = 15 mmHg) under room air inhalation, and PA hypertension was induced in 4 additional patients after hypoxic gas inhalation. There was no incidence of PA pressure or PVR values registering above the preoperative level. The degree of PA hypertension showed a correlation with the rate of PAC decrease and also with patients' age-at-operation. Multiple regression analysis showed that both the rate of PAC decrease and the age-at-operation contributed significantly to the degree of PA hypertension. Some of the patients over age 2 had a decreased rate of PAC above the regression line, which none of the patients under age 2 experienced. In patients with Heath-Edward grade III or less, residual pulmonary hypertension in the immediate postoperative period was not correlated with histology, but in late follow-up, it was with PAC and the age-at-operation. Therefore, a decrease of PAC is assumed to be a totally or partially irreversible pulmonary vascular change depending on the patient's age-at-operation, while medial hypertrophy is thought to be a reversible pulmonary vascular change. Lung biopsy could play an important role in determining the reversibility of pulmonary vascular obstruction, particularly in patients older than 2 years. Ed- re highlights above: such hyphenation is optional, but if used then it should be applied consistently throughout the paper. As 3 of the 4 entries in the abstract use it, I have maintained it consistently below.

Adolescent↗