Elongation of intercostal nerve cutaneous branches for breast and nipple neurotization during breast reconstruction after mastectomy for breast cancer: case-control study.

BACKGROUND: To restore sensation after breast reconstruction, a modified surgical approach was employed by identifying the cut fourth intercostal lateral cutaneous branch, elongating it with intercostal nerve grafts, and coapting it to the innervating nerve of the flap or by using direct neurotization of the spared nipple/skin. METHODS: This was a retrospective case-control study including 56 patients who underwent breast neurotization surgery. Breast operations included immediate reconstruction after nipple-sparing mastectomy (36 patients), skin-sparing mastectomy (8 patients), and delayed reconstruction with nipple preservation (7 patients) or without nipple preservation (5 patients). Patients who underwent breast reconstruction without neurotization were included as the non-neurotization negative control group. The contralateral normal breasts were included as positive controls. RESULTS: The mean(s.d.) monofilament test values were 0.07(0.10) g for the positive control breasts and 179.13(143.31) g for the breasts operated on in the non-neurotization group. Breasts that underwent neurotization had significantly better sensation after surgery, with a mean(s.d.) value of 35.61(92.63) g (P < 0.001). The mean(s.d.) sensory return after neurotization was gradual; 138.17(143.65) g in the first 6 months, 59.55(116.46) g at 7-12 months, 14.54(62.27) g at 13-18 months, and 0.37(0.50) g at 19-24 months after surgery. Two patients had accidental rupture of the pleura, which was repaired uneventfully. One patient underwent re-exploration due to a lack of improvement 1.5 years after neurotization. CONCLUSION: Using the lateral cutaneous branch of the intercostal nerve as the innervating stump and elongating it with intercostal nerve grafts is a suitable technique to restore sensation after mastectomy. This method effectively innervates reconstructed breasts and spares the nipple/skin with minimal morbidity.

Does Steal Phenomenon Exist in Multiple Neurotization?-An Experimental Rat Study.

BACKGROUND: Nerve transfers from one common donor nerve to recipient nerves with multiple target branches can yield slower and unpredictable recovery in the target nerves. Our hypothesis is that steal phenomenon exists when multiple nerve neurotization comes from one donor nerve. METHODS: In 30 Sprague-Dawley rats, the left ulnar nerve (UN) was selected as the donor nerve, and the musculocutaneous nerve (MCN) and median nerve (MN) as the recipient target nerves. The rats were separated into three groups (10 rats in each): group A, UN-to-MCN (one-target); group B, UN-to-MN (one-target); and group C, UN-to-MCN and MN (two-target). The right upper limbs were nonoperative as the control group. Outcome obtained at 20 weeks after surgery included grooming test, muscle weight, compound muscle action potential, tetanic muscle contraction force, axon counts, and retrograde labeling of the involved donor and target nerves. RESULTS: At 20 weeks after surgery, muscles innervated by neurotization resulted in significant worse outcomes than the control side. This was especially true in two-target neurotization in the parameter of muscle weight and forearm flexor muscle contraction force outcome when compared to one-target neurotization. Steal phenomenon does exist because flexor muscle contraction force was significantly worse during two-target neurotization. CONCLUSION: This study proves the existence of steal phenomenon in multiple target neurotization but does not significantly affect the functional results. Postoperative rehabilitative measures (including electrical stimulation, induction exercise) and patient compliance (ambition and persistence) are other crucial factors that hold equivalent importance to long-term successful recovery.

The Evolution of the Reconstructive Strategy for Elbow Flexion for Acute C5, C6 Brachial Plexus Injuries over Two Decades.

BACKGROUND: Over the course of the past two decades, improved outcomes following brachial plexus reconstruction have been attributed to newer nerve transfer techniques. However, key factors aside from surgical techniques have brought improved consistency to elbow flexion techniques in the latter decade. METHODS: One-hundred seventeen patients who underwent brachial plexus reconstruction from 1996 to 2006 were compared with 120 patients from 2007 to 2017. All patients were evaluated preoperatively and postoperatively to assess the recovery time and of elbow flexion strength. RESULTS: In the first decade, nerve reconstruction methods included proximal nerve grafting, intercostal nerve transfer, and Oberlin-I transfer. In the second decade, newer methods such as double fascicular transfer and ipsilateral C7 division transfer to the anterior division of upper trunk were introduced. About 78.6% of the first decade group versus 87.5% of the second decade group were able to reach M3 flexion strength (p = 0.04), with shorter time recovery to reach M3 in the 2nd decade. About 59.8% of the first decade group versus 65.0% of the second decade group were able to reach M4 (p = 0.28), but no significant difference in time of recovery. In both groups, the double fascicular nerve transfer had the highest impact when introduced in the second decade. More precise magnetic resonance imaging (MRI) techniques helped to diagnose the level of injury, the roots involved and evaluate the health of the donor nerves in preparation for intraplexus transfer. CONCLUSION: In addition to modified techniques in nerve transfers, (1) MRI-assisted evaluation and surgical exploration of the roots with (2) more judicious choice of donor nerves for primary nerve transfer were factors that ensured reliable and outcomes in the second decade.

Dynamic Eye Closure Restoration in Facial Palsy with Neurotized Platysma Muscle Graft in Rats.

BACKGROUND: One of the most devastating deficits of facial paralysis is eyelid dysfunction, which is controlled by the orbicularis oculi muscle (OOM), as it leads to loss of the protective mechanism of the eye. This study used a rat model to assess the functional outcomes of neurotized platysma muscle grafts (PMGs) for OOM replacement. METHODS: Forty male Sprague-Dawley rats with iatrogenic right eyelid dysfunction were divided into five groups: one control group and four groups utilizing PMG with different sources of nerve innervation. Eyelid function recovery was assessed at 2, 4, 6, and 8 weeks. The PMGs were harvested for pathological examination at the end of the study. RESULTS: All rats except those in the control group and one from the group using ipsilateral frontal and upper zygomatic frontal nerve branches directly neurotized to the PMG (nerve-to-muscle) recovered eyelid closure function within 8 weeks of the study period. The mean recovery time was 3.87 ± 1.28 weeks. A total of 87.5% of rats that had the contralateral zygomatic branch as the donor nerve regained the consensual corneal reflex (p-value < 0.001). CONCLUSION: Replacement of neurotized PMG for OOM function is successful in a rat model. Using the upper zygomatic branch as the donor nerve, it was possible to restore the consensual corneal reflex. This method shows promise for further human studies.

The Impact of Exercise on Motor Recovery after Long Nerve Grafting-Experimental Rat Study.

BACKGROUND: Long nerve grafting often results in unsatisfactory functional outcomes. In this study we aim to investigate the effect of swimming exercise on nerve regeneration and functional outcomes after long nerve grafting. METHODS: A reversed long nerve graft was interposed between C6 and the musculocutaneous nerve in 40 rats. The rats were divided into four groups with 10 in each based on different postoperative swimming regimes for rehabilitation: group A, continuous exercise; group B, early exercise; group C, late exercise; and group D, no exercise (control group). A grooming test was assessed at 4, 8, 12, and 16 weeks postoperatively. Biceps muscle compound action potential (MCAP), muscle tetanic contraction force (MTCF), and muscle weights were assessed after 16 weeks. Histomorphometric analyses of the musculocutaneous nerves were performed to examine nerve regeneration. RESULTS: The grooming test showed all groups except group D demonstrated a trend of progressive improvement over the whole course of 16 weeks. Biceps MCAP, MTCF, and muscle weights all showed significant better results in the exercise group in comparison to the group D at 16 weeks, which is especially true in groups A and B. Nerve analysis at 16 weeks, however, showed no significant differences between the exercise groups and the control group. CONCLUSIONS: Swimming after long nerve grafting can significantly improve muscle functional behavior and volume. The effect is less evident on nerve regeneration. Continuous exercise and early exercise after surgery show more optimal outcomes than late or no exercise. Having a good habit with exercise in the early period is thought as the main reason. Further studies are needed to determine the optimal exercise regimen.

Supercharge End-to-Side Sensory Transfer to A Long Nerve Graft to Enhance Motor Regeneration in A Brachial Plexus Model-An Experimental Rat Study.

BACKGROUND: Long nerve grafts will affect muscle recovery. Aim of this study is to investigate if supercharged end-to-side (SETS) sensory nerve transfer to long nerve graft can enhance functional outcomes in brachial plexus animal model. METHODS: A reversed long nerve graft (20-23-mm) was interposed between C6 and musculocutaneous nerve (MCN) in 48 SD rats. The sensory nerves adjacent to the proximal and distal coaptation sites of the nerve graft were used for SETS. There were four groups with 12 rats in each: (A) nerve graft alone, (B) proximal SETS sensory transfer, (C) distal SETS sensory transfer, and (D) combined proximal and distal SETS sensory transfers. Grooming test at 4, 8, 12 and 16 weeks, and compound muscle action potentials (CMAP), biceps tetanic muscle contraction force, muscle weight and MCN axon histomorphologic analysis at 16 weeks were assessed. RESULTS: Grooming test was significantly better in group C and D at 8 weeks (p = 0.02 and p = 0.04) and still superior at 16 weeks. There was no significant difference in CMAP, tetanic muscle contraction force, or muscle weight. The axon counts showed all experimental arms were significantly higher than the unoperated arms. Although the axon count was lowest in group C and highest in group D (p = 0.02), the nerve morphology tended to be better in group C overall. CONCLUSION: Distal sensory SETS transfer to a long nerve graft showed benefits of functional muscle recovery and better target nerve morphology. Proximal sensory inputs do not benefit the outcomes at all.

Outcomes of Functioning Free Gracilis Muscle Transplantation to Restore Elbow Flexion in Late Brachial Plexus Birth Injury.

BACKGROUND: Restoring elbow function is challenging after late presenting brachial plexus birth injury (BPBI). Free functioning muscle transplantation (FFMT) using the gracilis muscle is a reliable procedure to restore elbow flexion in patients with impaired function after spontaneous recovery or failed surgical reconstruction. METHODS: A retrospective review was performed on BPBI patients more than 2 years of age who received a FFMT between January 1993 and January 2018, with the aim of improving elbow flexion as the primary or secondary functional goal. Patients with preoperative elbow flexion Medical Research Council (MRC) grades less than 3 with more than or equal to 18 months of follow-up duration were included in the analysis. Patient demographic information and pre/postoperative clinical parameters including elbow flexion MRC scale, passive elbow range of motion, and complications were recorded. Surgical data including donor nerve choice, site of the FFMT tendon attachment, and necessity of concomitant procedures or reoperation were also analyzed. RESULTS: Fifty-six FFMTs were performed for the primary (29 patients) or secondary (26 patients) objective of restoring elbow flexion. The mean age at the time of the procedure was 9.6 years (standard deviation [SD] = 6.29, R = 3-35). Mean follow-up was 7.9 years (SD = 5.2). Elbow flexion improved from a median MRC grade 2 to 4 after a FFMT (p < 0.05). Patients who had a FFMT to restore two functions had 86% lower elbow flexion MRC grades than those who had a FFMT to restore flexion only (p < 0.05). Patients less than 12 years old at the time of surgery had more complications, reoperations, and rates of a flexion contracture more than or equal to 30 degrees than those aged more than 12 years (p < 0.05). CONCLUSION: FFMT is a reliable option for upper extremity reanimation. Patients aged less than 12 years old at the time of FFMT had significantly more complications, reoperations, and rates of postoperative elbow flexion contracture more than or equal to 30 degrees, but equivalent elbow flexion MRC grades. LEVEL OF EVIDENCE: III.

Long-Term Outcome of 118 Acute Total Brachial Plexus Injury Patients Using Free Vascularized Ulnar Nerve Graft to Innervate the Median Nerve.

BACKGROUND: The restoration of finger movement in total brachial plexus injuries (BPIs) is an ultimate challenge. Pedicled vascularized ulnar nerve graft (VUNG) connecting a proximal root to distal target nerves has shown unpredictable outcomes. We modified this technique by harvesting VUNG as a free flap to reinnervate median nerve (MN). We analyzed the long-term outcomes of these methods. METHODS: From years 1998 to 2015, 118 acute total brachial plexus patients received free VUNG to innervate the MN. Patients were followed up at least 5 years after the initial surgery. Donor nerves included the ipsilateral C5 root (25 patients) or contralateral C7 root (CC7 = 93 patients). Recovery of finger and elbow flexion was evaluated with the modified Medical Research Council system. Michigan Hand Score and Quick-DASH were used to represent the patient-reported outcomes. RESULTS: For finger flexion, ipsilateral C5 transfer to MN alone yielded similar outcomes to MN + MCN (musculocutaneous nerve), while CC7 had significantly better finger flexion when coapted to MN alone than to MN + MCN. Approximately 75% patients were able to achieve finger flexion with nerve transfer alone. For elbow flexion, best outcome was seen in the ipsilateral C5 to MCN and MN. CONCLUSION: In acute total BPI, the priority is to identify the ipsilateral C5 root to innervate MN, with concomitant innervation of MCN to establish the best outcomes for finger and elbow flexion. CC7 is more reliable when used to innervate one target (MN). LEVEL OF EVIDENCE: III.

Double Fascicular Transfer Using Partially Injured Donor Nerves: Is It Powerful Enough to Restore Elbow Flexion in Acute Brachial Plexus Injuries?

BACKGROUND: Loss of elbow flexion is a common sequela of acute brachial plexus injuries (BPIs). The Mackinnon/Oberlin-II double fascicular transfer (DFT) is a widely used method to restore this function in acute C5-6 or C5-7 injuries. This study attempted to evaluate if this technique can be applied reliably for cases involving C8 and/or T1 injuries. METHODS: Adult patients with acute BPIs who underwent the Mackinnon/Oberlin-II DFT in our center between 2008 and 2018 were retrospectively identified. Group I (n = 37) included patients with only C5-6 or C5-7 injury, while group II (n = 32) patients presented C5-8 ± T1 injuries. The demographic data, pre- and postoperative neurologic evaluations, electrodiagnostic studies, and grip strength assessment were collected. RESULTS: A total of 69 patients met the inclusion criteria. Preoperatively, the patients in group II presented poorer nerve conduction and electromyography in both the median and the ulnar nerves and the supply muscles. The percentage of M3 achievement in both groups was 91.9 versus 87.5% and M4 was 73.0 and 71.9%, respectively, which both were not statically significant but the achievement of group II was slower than the group I, 1 to 2 months slower, respectively. Both groups had 57.57 and 46.0% of the postoperative grip power compared with the healthy side, the result of shoulder abduction was not different (p = 0.480). CONCLUSION: With careful preoperative evaluation, early intervention, appropriate intraoperative functional fascicle selection, and aggressive postoperative rehabilitation, indications for the Mackinnon/Oberlin-II DFT technique can safely include acute C5-8 injuries and even partial T1 acute BPIs.

End-to-Side Anterior Interosseous Nerve Transfer: A Valuable Alternative for Traumatic High Ulnar Nerve Palsy.

BACKGROUND: The prognosis of high ulnar nerve injury is poor despite nerve repair or grafting. Anterior interosseous nerve (AIN) transfers provide a satisfactory recovery. However, the efficacy of end-to-side (ETS) AIN transfer and optimal timing in Sunderland grade IV/V of high ulnar nerve injury is lacking. OBJECTIVE: The goals were to compare the outcomes of high ulnar nerve injury managed with ETS AIN transfers with those managed with conventional procedures (nerve repair or graft only) and identify differences between early and delayed transfers. METHODS: Patients with isolated high ulnar nerve injury (Sunderland grade IV/V) from 2010 to 2017 were recruited. Patients with conventional treatments and AIN transfers were designated as the control and AIN groups, respectively. Early transfer was defined as the AIN transfer performed within 8 weeks postinjury. Outcomes were measured and analyzed by the British Medical Research Council (BMRC) score, grip strength, and pinch strength. RESULTS: A total of 24 patients with high ulnar nerve injury (Sunderland grade IV/V) were included. There were 11 and 13 patients in the control and AIN groups, respectively. In univariate analysis, both early and delayed AIN transfers demonstrated significantly better motor recovery among BMRC score and strength of grip and pinch at 12 months (P < 0.05). No statistical significance was found between early and delayed transfer. In multivariate analysis, both early and delayed transfers were regarded as strong and independent factors for motor recovery of ulnar nerve. Compared with the control, early [odds ratio (OR), 1.83; P < 0.001] and delayed (OR, 1.59; P < 0.001) transfers showed significant improvement with regard to BMRC scores. The pinch strength in early (OR, 31.68; P < 0.001) and delayed (OR, 26.45; P < 0.001) transfers was also significantly better. CONCLUSION: The ETS AIN transfer, in either early or delayed fashion, significantly improved intrinsic motor recovery in high ulnar nerve injuries classified as Sunderland grade IV/V. The early transfer group demonstrated a trend toward better functional recovery with less downtime.

Reversal of thoracic sympathectomy through robot-assisted microsurgical sympathetic trunk reconstruction with sural nerve graft and additional end-to-side coaptation of the intercostal nerves: A case report.

Thoracic sympathectomy to treat palmar hyperhidrosis (PH) has widely been performed. Many patients regret the surgery due to compensatory hyperhidrosis (CH), gustatory hyperhidrosis, arrhythmia, hypertension, gastrointestinal disturbances, and emotional distress. Robotic applications in microsurgery are very limited. We report the technique and long-term patient-reported outcomes of bilateral robot-assisted microsurgical sympathetic trunk reconstruction with a sural nerve graft in an interdisciplinary setting. A 59-year-old female suffered from severe adverse effects after endoscopic thoracic sympathectomy (ETS) for PH 25 years ago. She reported CH over the whole trunk, gustatory hyperhidrosis, excessive dry hands, and emotional distress. An interdisciplinary surgical team performed a bilateral sympathetic trunk reversal reconstruction with an interpositional sural nerve graft per side by a da Vinci® Robot. The nerve graft was microsurgically coapted using 9-0 sutures end-to-end to the sympathetic trunk stumps and side-to-end to the intercostal nerves T2-T4. At 24, 33 and 42 months, palmar dryness and emotional distress were strongly reduced. A highly specialized interdisciplinary setting may provide a precise, safe, and efficient treatment for ETS sequelae. A clinical study is initiated to validate this new therapy.

Robotic-Assisted Peripheral Nerve Surgery: A Systematic Review.

BACKGROUND: Robotic-assisted techniques are a tremendous revolution in modern surgery, and the advantages and indications were well discussed in different specialties. However, the use of robotic technique in plastic and reconstructive surgery is still very limited, especially in the field of peripheral nerve reconstruction. This study aims to identify current clinical applications for peripheral nerve reconstruction, and to evaluate the advantages and disadvantages to establish potential uses in the future. METHODS: A review was conducted in the literatures from PubMed focusing on currently published robotic peripheral nerve intervention techniques. Eligible studies included related animal model, cadaveric and human studies. Reviews on robotic microsurgical technique unrelated to peripheral nerve intervention and non-English articles were excluded. The differences of wound assessment and nerve management between robotic-assisted and conventional approach were compared. RESULTS: Total 19 studies including preclinical experimental researches and clinical reports were listed and classified into brachial plexus reconstruction, peripheral nerve tumors management, peripheral nerve decompression or repair, peripheral nerve harvesting, and sympathetic trunk reconstruction. There were three animal studies, four cadaveric studies, eight clinical series, and four studies demonstrating clinical, animal, or cadaveric studies simultaneously. In total 53 clinical cases, only 20 (37.7%) cases were successfully approached with minimal invasive and intervened robotically; 17 (32.1%) cases underwent conventional approach and the nerves were intervened robotically; 12 (22.6%) cases converted to open approach but still intervened the nerve by robot; and 4 (7.5%) cases failed to approach robotically and converted to open surgery entirely. CONCLUSION: Robotic-assisted surgery is still in the early stage in peripheral nerve surgery. We believe the use of the robotic system in this field will develop to become popular in the future, especially in the fields that need cooperation with other specialties to provide the solutions for challenging circumstances.

Reliability of Various Predictors for Preoperative Diagnosis of Infraclavicular Brachial Plexus Lesions with Shoulder and/or Elbow Paresis.

BACKGROUND: The distinction between supraclavicular and infraclavicular acute brachial plexus injuries (BPIs) could be challenging in cases of combined shoulder and elbow paresis. The reliability of several preoperative predictors was investigated to avoid unnecessary dissection, prolonged operation time, increased postoperative morbidity, and long scars. METHODS: Between 2004 and 2013, 75 patients, who sustained acute BPI and presented with motor paresis of shoulder and elbow with preservation of hand function, were included and studied retrospectively. Various predictors including muscles function, sensation, fractures, Tinel's sign and nerve conduction velocity (NCV) studies were reviewed. RESULTS: The highest odds ratio (OR) values for infraclavicular BPI were healthy clavicular head of pectoralis major and biceps, presenting with OR = 36.5 and 31.76, respectively, which were identified the most important predictors. CONCLUSION: A combination of functioning pectoralis major or biceps, scapular fracture, an infraclavicular Tinel's sign, and normal NCV in the musculocutaneous nerve was highly predictive of an infraclavicular level.

Effect of Degree of Arterial Inflow on a Functioning Free Muscle Transplantation in a Rat Gracilis Model.

BACKGROUND: Various surgical effects have previously been studied in an attempt to improve the functional outcome of the functioning free muscle transplantation (FFMT). However, the effect of the recipient arterial inflow on the FFMT has remained uninvestigated. This study was to investigate whether or not high flow versus low flow will affect the functional outcome of FFMT. METHODS: Rat's left gracilis FFMT model was devised and the nutrient arterial inflow was modified. Twenty-four Lewis rats were divided evenly into relatively high (0.071 mL/min) and relatively low (0.031 mL/min) blood flow groups (p < 0.001). The unoperated right sides served as the controls. Cases resulting in poor function were additionally grouped as functional failure group for comparison. Regular swimming exercise was implemented at 1 month postoperatively for 3 months. Gracilis muscle functions were then evaluated. RESULTS: Compared groups were: control (n = 13), low blood flow (n = 10), high blood flow (n = 8), and functional failure (n = 5). The control group showed superior functional results over the experimental groups (p < 0.0001). In the experimental group, successful group showed superior over the poor function group (p < 0.01). However, there was no significant difference between the high- and low-flow groups. CONCLUSION: This is the first study to evaluate the effect of arterial inflow on the FFMT. The rate of blood flow (relatively high vs. low) has little effect on the functional outcome of transferred muscle. Survival of FFMT is the major concern while performing FFMT surgery. Arterial inflow while choosing the recipient artery is not the factor for consideration.

Impact of Social Media on Current Medical Conferences.

BACKGROUND: Medical conferences are forums for research, continuing medical education, and networking. Social media is increasingly used for communication and networking due to its low cost and ability to overcome large distances. This study investigates the impact that social media brings to the current conference system. METHODS: There are three parts of this study: (1) comparing two similar brachial plexus injuries (BPIs) courses without (2009) and with (2017) social media support, and the participants' feedback; (2) sharing our experiences in the management of the 2018 International Course on SuperMicrosurgery (ICSM) conference; and (3) evaluating the studies from the social media platform International Microsurgery Club (IMC), for the consensus pertaining to social media and conference system. RESULTS: With the help of social media, international attendance increased during the 2017 BPI conference compared with the 2009 BPI course (25 nationalities in 2009 vs. 35 in 2017). At least 23% obtained their meeting information through social media. Live surgery was the overall main attraction (79%). The 2018 ICSM meeting revealed that video posts increased attendance; videos that were the most effective in attracting (viewership) were either short or pertained to surgical procedures. Facebook, Messenger, and WeChat smartphone applications were effective for immediate communication and troubleshooting among the participants. From the IMC polls, 78% believe that the social media and the conference complemented each other. 97% attended the conference to update their skills and knowledge. CONCLUSION: Social media is a quick and economic tool in promoting medical conferences and instant messenger systems offer immediate communication amongst associates. Despite the popularity of social media, the conference still has its irreplaceable role. The combination of the conference and the social media enhances the training and education of microsurgeons.

Lymphangiomatous Tumors of the Neck: Tips to Avoid Iatrogenic Nerve Injuries in the Brachial Plexus Region.

Lymphangiomas are rare malformations of the lymphatic system and can often be found in the neck region, where its proximity to the brachial plexus may cause compressive neuropathy and possible iatrogenic injuries during dissection. We report 4 cases of lymphangiomas with compression of the brachial plexus that were successfully removed without permanent nerve injuries and present a literature review of the preoperative approach and surgical techniques. A preoperative multidisciplinary approach can help surgeons predict what they may encounter during the surgery. A careful and stepwise dissection of the vital structures surrounding the tumor, especially the brachial plexus anatomy, is critical to avoiding severe complications. Incomplete resection or leakage of the lymph could result in higher rate of recurrence.

Comparison of Functional Results After Cross-Face Nerve Graft-, Spinal Accessory Nerve-, and Masseter Nerve-Innervated Gracilis for Facial Paralysis Reconstruction: The Chang Gung Experience.

BACKGROUND: Using functioning free muscle transplantation (FFMT) for facial paralysis and postparalysis facial synkinesis reconstruction is our preferred technique. Gracilis was the first choice of muscle. Three motor neurotizers: cross-face nerve graft (CFNG), spinal accessory nerve (XI) and masseter nerve (V3) have been used as neurotizers for different indications. METHODS: A total of 362 cases of facial reanimation with FFMT were performed between 1986 and 2015. Of these, 350 patients with 361 FFMT were enrolled: 272 (78%) patients were treated by CFNG-gracilis, 56 (15%) by XI-gracilis, and 22 (6%) by V3-gracilis. Smile excursion score, cortical adaptation stage with tickle test for spontaneous smile, facial synkinesis, satisfaction score by questionnaire, and functional facial grading were used for outcome assessment. RESULTS: The CFNG-gracilis in a 2-stage procedure achieved most natural and spontaneous smile when longer observation (≥2 years) was followed. The single-stage procedure using the XI-gracilis has proven a good alternative. V3-gracilis provided high smile excursion score in the shortest rehabilitation period, but never obtained spontaneous smile. CONCLUSIONS: The CFNG-gracilis remains our first choice for facial paralysis reconstruction which can achieve natural and spontaneous smile. XI- or V3-gracilis can be selected as a save procedure when CFNG-gracilis fails. The V3-gracilis is indicated in some specific conditions, such as bilateral Möbius syndrome, older patients (age, >70 years), or patients with malignant disease.

Distal Nerve Transfers: A Perspective on the Future of Reconstructive Microsurgery.

BACKGROUND: Nerve transfer can be broadly separated into two categories: proximal nerve graft and/or transfer and distal nerve transfer. The superiority of proximal nerve graft/transfer over distal nerve transfer strategy has been debated extensively, but which strategy is the best has not yet been defined. Each technique has its own advantages and disadvantages. However, proximal nerve graft/transfer is still the main reconstructive procedure based on the principle of "no diagnosis, then no treatment." Proximal nerve transfer can avoid iatrogenic injury where the lesion is still in continuity and neurolysis is the only procedure without further cutting the nerve. RESULTS: Our clinical and experimental study show that proximal nerve grafts/transfers yield at least equal or better results compared to distal nerve transfers. Proximal nerve grafts/transfers remain the mainstay of my reconstructive strategy. Proximal nerve graft/transfer offers more accurate diagnosis and proper treatment to restore shoulder and elbow functions simultaneously. Distal nerve transfers can offer more efficient elbow flexion. CONCLUSION: Combined, both strategies in primary nerve reconstruction are especially recommended when there is no healthy or not enough donor nerve available Distal nerve transfers should be considered as a complementary option for proximal nerve grafts/ transfers.

Can an injured nerve be used as a donor nerve for distal nerve transfer?-An experimental study in rats.

BACKGROUND: Distal nerve transfer has proven efficacy. The purpose of this study was to investigate if an injured nerve can be used as a donor nerve for transfer, and to determine the threshold of injury. MATERIALS AND METHODS: Rat's left ulnar-nerves in the axilla with different degrees of injury were selected as the donor nerves for transfer, and the musculocutaneous-nerves the target nerves for being re-innervated. Six rats each served as positive and negative controls: Group A, intact ulnar-nerve transfer; and Group E, the ulnar-nerve was cut but no transfer. Ten rats each were assigned to Group B to Group D with 25%, 50%, and 75% transected ulnar-nerve, respectively and all were transferred to the musculocutaneous-nerve. After a 12-week recovery period, outcomes were evaluated. RESULTS: Biceps muscle weight measurements showed all experimental groups-D 0.28 ± 0.02 g/72%, C 0.28 ± 0.03 g/73%, B 0.29 ± 0.04 g/74%, and A 0.29 ± 0.04 g/80%-were lighter than group H 0.36 ± 0.04 g, which were all statistically significant (P < 0.001). Muscle tetanus contraction force measurements were the lowest in group D35 ± 8.6 g/69%. Groups C and B measured 41 ± 8.5 g/75% and 40 ± 2.2 g/77% and group A 41 ± 9.4 g/95%, respectively. Group H showed muscle contraction force of 52 ± 7.2 g, which was statistically significant when compared to experimental groups (P < 0.05-0.001). EMG measurements of the biceps muscles showed: group D was 3.6 ± 0.7 mV/69%, group C was 3.6 ± 0.6 mV/75%, and group B was 4.2 mV ± 0.7/81%. Group H was5.1 ± 0.7 mV and statistically significant different when compared with experimental groups (P < 0.05-0.001).Axon counts of healthy ulnar-nerve (Group H) were 1849 ± 362. Axon counts of the injured ulnar-nerve were in group B 1447 ± 579/78%, group C 1051 ± 367/57% and group D 567 ± 230/31%. CONCLUSION: The donor nerve should be healthy in order to provide optimal result. A big nerve (e.g., ulnar nerve) but injured with at least 75% axon spared is still potentially effective for transfer. In contrast, a small nerve (e.g., intercostal nerve) once injured with 75%axon spared would be considered a suboptimal donor nerve.

The Spinal Accessory Nerve for Functional Muscle Innervation in Facial Reanimation Surgery: An Anatomical and Histomorphometric Study.

INTRODUCTION: Facial reanimation surgery is performed in severe cases of facial palsy to restore facial function. In a 1-stage procedure, the spinal accessory nerve can be used as a donor nerve to power a free gracilis muscle transplant for the reanimation of the mouth. The aim of this study was to describe the surgical anatomy of the spinal accessory nerve, provide a guide for reliable donor nerve dissection, and analyze the available donor axon counts. METHODS: Dissections were performed on 10 nonembalmed cadavers (measurements of 20 nerves). Surgical anatomy of the spinal accessory nerve was described and distances to important landmarks were measured. Nerve biopsies were obtained of the main nerve trunk distal to the skull base, caudoposterior to the sternocleidomastoid muscle, proximal to the trapezius muscle and at the level of donor nerve harvest to analyze the myelinated axon count throughout the course of the spinal accessory nerve. The donor nerve length and available donor nerve axon count were the primary outcome parameters in this study. RESULTS: The mean donor nerve length was 11.6 cm. The spinal accessory nerve was transferred to the mandibular angle without tension for ideal coaptation to the free muscle transplant. After retraction of the trapezius muscle, a small distal nerve branch that leaves the main nerve trunk at a 90-degree angle medially was used as a landmark to indicate the level of donor nerve transection. On average, 1400 myelinated donor axons were available for innervation of the gracilis muscle transplant. CONCLUSIONS: This study gives a practical guide for spinal accessory nerve dissection for its application in facial reanimation as a motor source for the innervation of a free muscle transplant.