5 results on '"Tommy Nai-Jen Chang"'
Search Results
2. Factors Affecting C5 Viability and Demographic Variability in Two Brachial Plexus Centers
- Author
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Nicole A. Zelenski, MD, Nichole A. Joslyn, MD, Ying Hsuan Lee, MD, David Chwei-Chin Chuang, MD, Johnny Chuieng-Yi Lu, MD, MSCI, Tommy Nai-Jen Chang, MD, Robert J. Spinner, MD, Allen T. Bishop, MD, and Alexander Y. Shin, MD
- Subjects
Surgery ,RD1-811 - Abstract
Background:. Complete brachial plexus injuries are devastating injuries. A viable C5 spinal nerve can offer additional sources of axons and alter surgical treatment. We aimed to determine factors that portend C5 nerve root avulsion. Methods:. A retrospective study of 200 consecutive patients with complete brachial plexus injuries at two international centers (Mayo Clinic in the United States and Chang Gung Memorial Hospital in Taiwan) was performed. Demographic information, concomitant injuries, mechanism, and details of the injury were determined, and kinetic energy (KE) and Injury Severity Score were calculated. C5 nerve root was evaluated by preoperative imaging, intraoperative exploration, and/or intraoperative neuromonitoring. A spinal nerve was considered viable if it was grafted during surgery. Results:. Complete five-nerve root avulsions of the brachial plexus were present in 62% of US and 43% of Taiwanese patients, which was significantly different. Increasing age, the time from injury to surgery, weight, body mass index of patient, motor vehicle accident, KE, Injury Severity Score, and presence of vascular injury significantly increased the risk of C5 avulsion. Motorcycle (≤150cc) or bicycle accident decreased the risk of avulsion. Significant differences were found between demographic variables between the two institutions: age of injury, body mass index, time to surgery, vehicle type, speed of injury, KE, Injury Severity Score, and presence of vascular injury. Conclusions:. The rate of complete avulsion injury was high in both centers. Although there are a number of demographic differences between the United States and Taiwan, overall the KE of the accident increased the risk of C5 avulsion.
- Published
- 2023
- Full Text
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3. Utilization of the Rat’s Tail as a Novel Model for Arterialized Venous Flap
- Author
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Johnny Chuieng-Yi Lu, MD, MSCI, Gonzalo Mallarino-Restrepo, MD, Olivier Camuzard, MD, Tommy Nai-Jen Chang, MD, and David Chwei-Chin Chuang, MD, MSCI
- Subjects
Surgery ,RD1-811 - Abstract
Summary:. Arterialized tissues provide longevity and coverage of critically exposed tissue, and in pliable areas of the body, thin flaps are needed. Arterialized venous flaps provide all the aforementioned qualities, yet unpredictability in flap perfusion requires further investigation in experimental studies. Existing animal models are thicker in nature and rarely mimic commonly used venous flaps in clinical practice. A novel design of the rat’s tail provides an ideal model for arterialized venous flaps. Eleven venous flaps were harvested from the rats’ tail, all presenting with two parallel veins in configuration. Arterialization of veins using the femoral artery was done in either along-valve or against-valve fashion, with the purpose of testing the flap’s response to different clinical configurations. The vessel diameter and flap thickness were measured. Flap viability was monitored for 7 days after surgery to ensure stable flap viability. Thickness of the tail flap ranged from 1.0 to 1.2 mm, while the abdomen skin thickness ranged from 1.4 to 1.5 mm. The mean diameter of the lateral veins was 0.85 ± 0.08 mm, which was in between the average femoral artery diameter (mean 0.76 ± 0.1 mm) and the average femoral vein diameter (1.28 ± 0.2 mm). Four of the nine against-valve flaps achieved more than 50% flap survival, while all along-valve flaps achieved flap viability of more than 75%, as evident by indocyanine green imaging. This flap demonstrates similar properties to thin venous flaps used in clinical situations. Standardization of this model can push forth better understanding of the arterialization phenomenon in venous flaps for future studies.
- Published
- 2022
- Full Text
- View/download PDF
4. Postparalysis Facial Synkinesis: Clinical Classification and Surgical Strategies
- Author
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David Chwei-Chin Chuang, MD, Tommy Nai-Jen Chang, MD, and Johnny Chuieng-Yi Lu, MD
- Subjects
Surgery ,RD1-811 - Abstract
Background: Postparalysis facial synkinesis (PPFS) can occur after any cause of facial palsy. Current treatments are still inadequate. Surgical intervention, instead of Botox and rehabilitation only, for different degrees of PPFS was proposed. Methods: Seventy patients (43 females and 27 males) with PPFS were enrolled since 1986. They were divided into 4 patterns based on quality of smile and severity of synkinesis. Data collection for clinically various presentations was made: pattern I (n = 14) with good smile but synkinesis, pattern II (n = 17) with acceptable smile but dominant synkinesis, pattern III (n = 34) unacceptable smile and dominant synkinesis, and pattern IV (n = 5) poor smile and synkinesis. Surgical interventions were based on patterns of PPFS. Selective myectomy and some cosmetic procedures were performed for pattern I and II patients. Extensive myectomy and neurectomy of the involved muscles and nerves followed by functioning free-muscle transplantation for facial reanimation in 1- or 2-stage procedure were performed for pattern III and many pattern II patients. A classic 2-stage procedure for facial reanimation was performed for pattern IV patients. Results: Minor aesthetic procedures provided some help to pattern I patients but did not cure the problem. They all had short follow-up. Most patients in patterns II (14/17, 82%) and III (34/34, 100%) showed a significant improvement of eye and smile appearance and significant decrease in synkinetic movements following the aggressively major surgical intervention. Nearly, all of the patients treated by the authors did not need repeated botulinum toxin A injection nor require a profound rehabilitation program in the follow-up period. Conclusions: Treatment of PPFS remains a challenging problem. Major surgical reconstruction showed more promising and long-lasting results than botulinum toxin A and/or rehabilitation on pattern III and II patients.
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- 2015
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5. The Impact of Different Degrees of Injured C7 Nerve Transfer: An Experimental Rat Study
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Chieh-Han John Tzou, MD, PhD, David Chwei-Chin Chuang, MD, Tommy Nai-Jen Chang, MD, and Johnny Chuieng-Yi Lu, MD
- Subjects
Surgery ,RD1-811 - Abstract
Background: Ipsilateral C7 nerve transfer is an available procedure in C5C6 2-root avulsion injury of the brachial plexus. However, concomitant injury of a normal-looking C7 cannot be ruled out. The efficiency of a concomitant injury of C7 transfer was investigated. Methods: Forty-two Sprague-Dawley rats were randomly assigned to 5 groups. They all underwent a 2-stage procedure. In the first stage from dorsal spine approach, left C5 and C6 roots were avulsed and C7 was crushed with jeweler’s forceps with different degrees: group A (n = 6), C7 not injured; group B (n = 10), C7 crushed for 10 seconds; group C (n = 10), C7 crushed for 30 seconds; group D (n = 10), C7 doubly crushed for 60 seconds; and group E (n = 6), C7 transected and not repaired. Four weeks later in the second stage, the C7 was reexplored via volar approach, transected, and coapted to the musculocutaneous nerve. At 12 weeks following the nerve transfer, functional outcomes were assessed. Results: Grooming test, muscle weight, electromyography, and muscle tetanic contraction force all showed that the biceps muscles were significantly worse in group C (moderate crush) and group D (severe crush). Group B (mild crush) and group A (uninjured) showed no difference. Group E (C7 cut and not repaired) was the worst. Conclusions: An injured but grossly normal-looking ipsilateral C7 can be used as a motor source but with variable results. The result is directly proportional to the severity of injury, potentially implying that better results will be achieved when longer regeneration time is allowed.
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- 2014
- Full Text
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