Contralateral motor rootlets and ipsilateral nerve transfers in brachial plexus reconstruction

Object. The goal of this study was to evaluate outcomes in patients with brachial plexus avulsion injuries who underwent contralateral motor rootlet and ipsilateral nerve transfers to reconstruct shoulder abduction/external rotation and elbow flexion.

Methods. Within 6 months after the injury, 24 patients with a mean age of 21 years underwent surgery in which the contralateral C-7 motor rootlet was transferred to the suprascapular nerve by using sural nerve grafts. The biceps motor branch or the musculocutaneous nerve was repaired either by an ulnar nerve fascicular transfer or by transfer of the 11th cranial nerve or the phrenic nerve. The mean recovery in abduction was 90° and 92° in external rotation. In cases of total palsy, only two patients recovered external rotation and in those cases mean external rotation was 70°. Elbow flexion was achieved in all cases. In cases of ulnar nerve transfer, the muscle scores were M5 in one patient, M4 in six patients, and M3+ in five patients. Elbow flexion repair involving the use of the 11th cranial nerve resulted in a score of M3+ in five patients and M4 in two patients. After surgery involving the phrenic nerve, two patients received a score of M3+ and two a score of M4. Results were clearly better in patients with partial lesions and in those who were shorter than 170 cm (p < 0.01). The length of the graft used in motor rootlet transfers affected only the recovery of external rotation. There was no permanent injury at the donor sites.

Conclusions. Motor rootlet transfer represents a reliable and potent neurotizer that allows the reconstruction of abduction and external rotation in partial injuries.

Laryngeal abductor muscle reinnervation in a pig model

OBJECTIVE

To develop a large animal model for studies of laryngeal abductor reinnervation.

MATERIAL AND METHODS

Six minipigs underwent unilateral anastomosis of the phrenic nerve-abductor branch of the recurrent laryngeal nerve (RLN). Polyhydroxybutyrate (PHB) conduits were used for repair. At each of 30, 60 and 120 days, 2 animals underwent video laryngeal endoscopy (VLE) and were then killed. VLE was also performed in the 120-day pair at 60 days. Nerve-conduit-nerve-muscle samples were fixed for light and immunofluorescence (pan-neurofilaments, S-100) microscopy. Laryngeal muscles were harvested (myosin heavy chain analysis).

RESULTS

VLE showed recovery of abductor function in 1 animal at 60 days and in 1 at 120 days. Haematoxylin-eosin staining demonstrated a complex inflammatory response. Eosinophil recruitment was observed. Stepwise regeneration and reorganization of the distal nerve between 30 and 120 days was observed with pan-NF staining. The mean minimum diameter in the reinnervated posterior crico-arytenoids tended to increase for up to 120 days.

CONCLUSIONS

Anastomosis of the phrenic nerve-abductor branch of the RLN with a PHB conduit in a pig can result in functional and histological recovery within 2-4 months and appears to at least sustain abductor muscle fibre morphology. Recovery occurs despite a complex inflammatory response, which may be an essential part of healing rather than inhibitory.

Surgical options for complete resectable lung cancer invading the phrenic nerve

We describe a 58-year-old male diagnosed with a tumour of the left lung, which on subsequent thoracotomy proved to be invading the phrenic nerve. The clinical and spirometric outcome of a lobectomy, which resulted in a postoperative ipsilateral hemidiaphragmatic paralysis, versus the alternative surgical option of a pneumonectomy is discussed.

[Changes of energy metabolism in canine respiratory muscles after phrenic nerve transection]

OBJECTIVE

To examine the changes in energy metabolism in the respiratory muscles of canines with unilateral phrenic nerve transection using high-performance liquid chromatography (HPLC).

METHODS

The left phrenic nerve of 8 canines was transected and the contents of adenine nucleotide in respiratory muscles were determined by HPLC before and 1 and 2 months after the operation.

RESULTS

In the intercostal muscles, ATP contents remained almost unchanged during the entire course of the observation, while ADP content was elevated 2 months after the operation as compared with that measured before and 1 month after the operation (P<0.05). One month postoperatively, the content of total adenylic acid (TAN) decreased to the lowest point, but the difference between the measurements was not statistically significant; also at 1 month after the operation, the content of adenylate energy charge (AEC) was the lowest, with statistically significant difference from the measurements before and 2 months after the operation (P<0.05). In the diaphragm, the contents of ATP, ADP, TAN and AEC 2 months postoperatively were 9.05+/-12.70, 2.99+/-2.57, 14.72+/-13.98, 0.57+/-0.29, significantly different from the levels at the other two time points (P<0.05).

CONCLUSION

After unilateral phrenic nerve transection in canines, the energy metabolism of the diaphragm declines significantly, whereas that of the intercostal muscle can be compensated to some extent.

Selective Transfer of the C7 Nerve Root: An Experimental Study

The authors present selective C7 nerve root transfer in a rat model. The musculocutaneous nerve was neurotized by various portions of ipsilateral C7. The latent period and maximum amplitude of evoked motor action potential of the biceps, number of regenerating myelinated nerve fibers, cross-sectional area and wet weight of the biceps, and twitch and tetanic tensions of the biceps were measured at four postoperative intervals. In the early postoperative period (1 and 2 months), nerve regeneration in neurotization with the posterior division or the anterior division of C7 was significantly better than that with the anterolateral fascicles of the anterior division or the phrenic nerve. As the postoperative interval prolonged, the parameters of nerve regeneration in the latter two groups approximated those in the former two groups. This indicated that there were enough regenerating nerve fibers in the anterolateral fascicles of the anterior division and a promising potential for nerve regeneration. The clinical significance of the results lies in the design of selective C7 transfer which, using the anterolateral fascicles of the anterior division, could preserve the function of the muscles innervated by the posterior division to the greatest extent, and provide sufficient donor outflow as well. It is therefore a new option for C7 transfer.

A fuzzy-classifier system to distinguish respiratory patterns evolving after diaphragm paralysis in the cat

We applied the fuzzy "k-nearest neighbor" (k-NN) classifier of the pattern recognition theory to fathom the abnormal way of breathing resulting from diaphragm paralysis and to distinguish the dominant component, tidal or frequency, of the breathing pattern on which ventilatory compensation relies in such a pathological state. We addressed this issue in the experimental model of diaphragm paralysis as a result of bilateral phrenicotomy in anesthetized, spontaneously breathing cats. Of several variables recorded, we selected two features, minute ventilation and arterial CO(2) tension, that were used for the k-NN analysis. The results demonstrate that the ability to maintain ventilation critically depended on the increase in frequency of breathing. Other breathing pattern strategies were ineffective. The k-NN evaluation with the two selected features discerned the prevailing pattern of breathing with sufficient probability. Such an evaluation may be a useful tool in predicting the development of compensatory strategies in disordered patterns of breathing.

Nerve transfers for severe brachial plexus injuries: a review

Nerve transfer procedures are increasingly performed for repair of severe brachial plexus injury (BPI), in which the proximal spinal nerve roots have been avulsed from the spinal cord. The procedure essentially involves the coaption of a proximal foreign nerve to the distal denervated nerve to reinnervate the latter by the donated axons. Cortical plasticity appears to play an important physiological role in the functional recovery of the reinnervated muscles. The author describes the general principles governing the successful use of nerve transfers. One major goal of this literature review is to provide a comprehensive survey on the numerous intra- and extraplexal nerves that have been used in transfer procedures to repair the brachial plexus. Thus, an emphasis on clinical outcomes is provided throughout. The second major goal is to discuss the role of candidate nerves for transfers in the surgical management of the common severe brachial plexus problems encountered clinically. It is hoped that this review will provide the treating surgeon with an updated list, indications, and expected outcomes involving nerve transfer operations for severe BPIs.

[Surgery for diaphragmatic palsy]

Diaphragmatic palsy leads to a permanent ascension of one or both hemi-diaphragms with highly variable functional impact. The underlying mechanisms can be divided into two main categories: neurological or muscular disorder leading to peripheral dysfunction; defective or non-transmitted central command causing central dysfunction. A complete morphological and functional work-up is required to determine the circumstances leading to diaphragmatic palsy and the uni- or bilateral nature of the paralysis. The entire phreno-diaphragmatic transmission chain from the cranium to the diaphragmatic muscle must be analyzed to search for a local cause. Function tests are used to examine central command and transmission, function of the phrenic nerve, and the capacity of the diaphragmatic muscle to generate sufficient pressure for efficacious ventilation. Once indirect causes of diaphragmatic ascension (independent of the phreno-diaphragmatic system) have been ruled out, surgery may be proposed for symptomatic, permanent and irreversible diaphragmatic paralysis. A tension procedure may be sufficient in the event of eventration with or without phrenic palsy. For well-selected patients with central paralysis due to supraspinal lesions with intact nerves and muscles, implantation of a phrenic pacemaker may be helpful to eliminate positive pressure mechanical ventilation and restore more physiological respiration.

Phrenic paresis and respiratory insufficiency associated with cervical spondylotic myelopathy

Cervical spondylotic myelopathy is a common disease caused by chronic segmental compression of the spinal cord. Despite the fact that the columns of the nuclei of the phrenic nerve are located between the 3rd and 5th cervical nerve segments, phrenic nerve paresis is not usually clinically significant. We present one case of cervical spondylotic myelopathy with bilateral phrenic paresis in whom magnetic resonance imaging and surgical findings confirmed intrinsic cord disease as being the cause of this syndrome. This case report suggests that one pathophysiology of clinical phrenic nerve paresis may be segmental damage to the anterior horns caused by cervical spondylosis.

Comparative experimental study on treatment outcome of nerve transfer, using selective C7 nerve root vs. phrenic nerve

The treatment outcome of nerve transfer using the C7 nerve root or phrenic nerve was compared in a rat experiment. One hundred and twenty SD rats were divided into two groups, one undergoing phrenic nerve transfer to the musculocutaneous nerve, and the other partial ipsilateral C7 (anteriolateral fascicles of the anterior division) to the musculocutaneous nerve. Neurotization outcomes of the two groups were evaluated by comparing the electrophysiologic, histologic, and myophysiologic changes of the biceps muscle. No significant differences were found between parameters from the phrenic nerve transfer group and those from the ipsilateral C7 nerve transfer group. This indicates that the treatment outcome of selective ipsilateral C7 transfer is comparable to that of phrenic nerve transfer. It is the surgery of choice in treating brachial plexus upper-trunk avulsion accompanied by phrenic nerve injury.

[An study on functioning remobilization of the paralyzed vocal cord by latero-terminal neurorrhaphy in rats]

OBJECTIVE

To investigate the effect and the clinic value of latero-terminal neurorrhaphy to treat vocal cord paralysis.

METHOD

Sixty SD rats were divided into three groups. In the experimental group, the right recurrent laryngeal nerve(RLN) was incised and anastomosed to the right phren nerve by means of latero-terminal neurorrhaphy. The internal nerve of the right RLN was incised and anastomosed to the right ansa cervicals nerve by end-to-end nerve anastomosis. In control group, the right RLN was incised and sutured to the right phren nerve by end-to-end nerve anastomosis. The internal nerve of the right RLN were incised and anastomosed to the right ansa cervicals nerve by end-to-end nerve anastomosis. In normal group rats, the nerves were only exposed. One to three months later, 10 rats from each group were examined for vocal cord movement and nerve regeneration by using fibrolaryngscope and nerve electromyography.

RESULT

One months after operation. This effect of latero-terminal neurorrhaphy had significant difference compared with the control group (P < 0.05). Three months after operation. This effect of latero-terminal neurorrhaphy had not significant difference compared with the control group (P > 0.05).

CONCLUSION

The latero-terminal neurorrhaphy has a similar treatment effect compared with end-to-end nerve anastomosis. This microsurgical technique provides a new method for treating vocal cord paralysis.

[Early microsurgical treatment of upper obstetrical brachial plexus injury]

OBJECTIVE

To search for the operation timing and methods for obstetrical brachial plexus injury (OBPI).

METHODS

Thirty-two children with upper OBPI were treated by microsurgical procedure from October 1997 to April 2001. The average age of patients was 10 months, ranged from 3 months to 24 months; of them, 19 were below 6 months while 13 were over 6 months. Surgical procedure included neurolysis(n = 12), coaptation after resection of the neuroma without function (n = 7), phrenic nerve transfer to anterior cord of upper trunk or musculocutaneous nerve (n = 7) and intercostal nerves transfer to musculocutaneous nerve(n = 6). The children underwent operation with microsurgical technique and 7/0 or 9/0 nylon was used for nerve suture.

RESULTS

Thirty cases were followed up for 21 months postoperatively; the excellent and good rate was 76.7% (23/30). The results of the children under 6 months were better than those over 6 months.

CONCLUSION

The microsurgical operation might be considered at the age of 3-6 month infants who had shown little or no improvement in elbow flexion. Neurolysis and nerve coaptation are superior to neurotization. The appropriate procedure should be selected according to the findings of exploration.

Reversed latissimus dorsi muscle flap for repair of recurrent congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Neonates with large congenital diaphragmatic hernias (CDH) require prosthetic patch closure of the defect because of the paucity of native diaphragmatic tissue. As the child grows, patch separation can occur necessitating reoperation. Use of vascularized autologous tissue may decrease the incidence of reherniation as tissue incorporation and growth may be improved. The authors report our early experience using a local muscle advancement flap with microneural anastomosis for those children in whom reherniation develops after prosthetic patch placement.

METHODS

Seven patients with CDH (6 left and 1 right) whose synthetic diaphragmatic patch separated from the chest wall resulting in a clinically significant recurrent hernia were followed up with prospectively. After dissecting the ipsilateral latissimus dorsi off the chest wall and dividing the thoracodorsal neurovascular bundle (based on its lumbar blood supply), the synthetic patch was removed via an eighth intercostal incision. The muscle flap was placed into the hemithorax through the bed of the tenth rib and sutured in place over a Vicryl mesh scaffold. The thoracodorsal nerve was anastomosed to the phrenic nerve. Functional analysis of the flap was performed in 4 patients.

RESULTS

Age at placement of the muscle graft ranged from 2 months to 48 months (median, 24 months). There has been no evidence of reherniation after placement of the muscle graft. Long-term outcome and functional analysis of the flap was available in 4 patients (mean, 19 months). Two infants had fluoroscopic and sonographic evidence of nonparadoxical neodiaphragmatic motion. In one of these, electromyographic evidence of function was documented with a phrenic nerve conduction velocity of 22 meters per second. The third infant showed no evidence of neodiaphragmatic motion, and the fourth infant had paradoxical motion.

CONCLUSIONS

This is the first direct documentation of phrenic nerve function in an infant with CDH. An innervated reversed latissimus dorsi (RLD) flap reconstruction for recurrent CDH provides an alternative to prosthetic patch repair. This technique offers the advantages of autologous vascularized tissue with potential phrenic nerve innervation and physiologic neodiaphragmatic motion.

The crossed phrenic phenomenon: a model for plasticity in the respiratory pathways following spinal cord injury

Hemisection of the cervical spinal cord rostral to the level of the phrenic nucleus interrupts descending bulbospinal respiratory pathways, which results in a paralysis of the ipsilateral hemidiaphragm. In several mammalian species, functional recovery of the paretic hemidiaphragm can be achieved by transecting the contralateral phrenic nerve. The recovery of the paralyzed hemidiaphragm has been termed the "crossed phrenic phenomenon." The physiological basis for the crossed phrenic phenomenon is as follows: asphyxia induced by spinal hemisection and contralateral phrenicotomy increases central respiratory drive, which activates a latent crossed respiratory pathway. The uninjured, initially latent pathway mediates the hemidiaphragm recovery by descending into the spinal cord contralateral to the hemisection and then crossing the midline of the spinal cord before terminating on phrenic motoneurons ipsilateral and caudal to the hemisection. The purpose of this study is to review work conducted on the crossed phrenic phenomenon and to review closely related studies focusing particularly on the plasticity associated with the response. Because the review deals with recovery of respiratory muscles paralyzed by spinal cord injury, the clinical relevance of the reviewed studies is highlighted.

Intractable hiccup: an odd complication after laparoscopic fundoplication for gastroesophageal reflux disease

Intractable hiccup can be an unbearable circumstance and its treatment is often frustrating. More than 100 causes for hiccup have been described in the literature; the most common cause is gastroesophageal reflux disease (GERD). We report a case of a 31-year-old patient who suffered from intractable hiccup starting 3 weeks after laparoscopic Nissen fundoplication for GERD, a potential surgical complication that has not been described. After frustrating medical treatment, the patient underwent computed tomography and nerve stimulator-guided blockade of vagal and phrenic nerves on each side separately. Hiccup ceased only after blockade of the right phrenic nerve with 4 ml/h l% ropivacaine and relapsed soon after discontinuation. He underwent thoracoscopic right phrenicectomy, which rendered him symptom free for well over 2 months, at the time of this writing.

Diaphragm plication following phrenic nerve injury: a comparison of paediatric and adult patients

BACKGROUND

A study was undertaken to evaluate whether adults differ from children in the indications and outcome of diaphragmatic plication following phrenic nerve injury.

METHODS

A retrospective study was performed of 21 patients, 10 below the age of 5 and 11 older than 37 years. The indication for surgery for all the children was failure to wean from ventilatory support. The indications for surgery in the adult group were ventilator dependency (n=4) and symptomatic dyspnoea (n=7). All patients had at least one imaging study confirming diaphragmatic paralysis. The American Thoracic Society (ATS) dyspnoea scale, pulmonary function tests, and quantitative pulmonary perfusion scans were used as evaluation parameters. At surgery the diaphragm was centrally plicated.

RESULTS

One child died immediately after surgery due to irreversible heart failure and two children died within 2 months of surgery from ongoing complications of their original condition. These three patients were considered as selection failures. Seven children were weaned from ventilatory support within a median of 4 days (range 2-140). Only one of four ventilated adults was successfully weaned. Seven adults who underwent surgery for chronic symptoms had a marked subjective improvement of 2-3 levels in the ATS dyspnoea scale. Pulmonary function studies in the seven symptomatic adults showed a 40% improvement above baseline. Severely asymmetrical perfusion scans reverted to a normal pattern after plication.

CONCLUSIONS

Diaphragmatic plication offers a significant benefit to children with diaphragmatic paralysis and should be performed early to facilitate weaning from mechanical ventilation. While plication is of limited benefit in weaning ventilated adults, it results in significant subjective and objective lifetime improvement in non-ventilated symptomatic adults.

[Reinnervation of the posterior cricoarytenoid muscle by the phrenic nerve for bilateral vocal cord paralysis in humans]

OBJECTIVE

To reestablish the respiratory abduction of the paralyzed vocal cord through reinnervation of the posterior cricoarytenoid(PCA) muscle by the phrenic nerve in humans.

METHODS

In six cases with bilateral recurrent laryngeal nerve paralysis, the phrenic nerve was anastomosed to the anterior branch of recurrent laryngeal nerve, while the adductor branch of recurrent laryngeal nerve was severed and its proximal end was implanted into the PCA muscle belly in one side, for the other side nerve-muscle pedicle technique was used. All cases had been subjected to preoperative and postoperative video laryngoscopy, stroboscopy, electromyography, voice recording and acoustic analysis.

RESULTS

Among the 6 patients, it is observed in five cases' phrenic nerve reinnervation side the inspiratory abducent motion evidently recovered, and the abducent range was from 3 to 5 mm, While only slight abductent motion or no motion could be recorded on the other side reinnervated with nerve-muscle pedicle technique, and the vocal cord excursion on this side was less than 1 mm in all cases. It is because the glottis is broad enough for the patients to have daily activities without short of breath, so all of them were decannulated postoperatively. The reinnervated PCA muscle by the phrenic nerve showed typical inspiratory high frequency discharge with 100-200 ms delay as compared with the other side, indicating the phrenic motoneuron pattern. No long-term diaphragmatic paralysis and lesion of respiratory function was found. All cases' voice was not weakened, and no aspiration occurred.

CONCLUSION

The phrenic reinnervation is feasible clinically for treating vocal cord paralysis, and it is found to be more effective for restoring inspiratory abducent function than the nerve-muscle pedicle technique.

[Applied anatomy for the reinnervation of posterior cricoarytenoid muscle by phrenic nerve for bilateral vocal cord paralysis]

OBJECTIVE

To study the anatomic basis for the anastomosis of phrenic nerve (PN) to the anterior branch of recurrent laryngeal nerve(RLN) for the treatment of the injured bilateral RLN.

METHODS

The origin and the nutritive arteries and the adjacent tissue construction of PNs in 46 cases were studied. The longest utilizable length of PNs and the distance from the root of PN to cricothyroid joint were measured. The sectional area and the number of myelinated fibers of PNs and the anterior branch of RLNs were measured by computer image processing system.

RESULTS

PNs coming from C4 comprised of 93.5%, 95.6% (44/46) of the nutritive arteries came from the ascending carotid artery and got into the cervical segment of PN from its root. The common trunk of PN was very deep, to the external of the common carotid artery and the vertebral vein, and deep to the internal jugular vein and thoracic duct (left), and in the superficies of the subclavian artery and in the deep of the subclavian vein when it was crossing the thoracic entrance. The distance from the root of PN to the level of the subclavian vein and to cricothyroid joint were (7.2 +/- 1.6) cm and (5.5 +/- 1.4) cm, respectively. The former was at least 1.5 cm longer than the latter. The average number of myelinated fibers and the sectional area of the PNs were 2.41 times and 2.15 times as many as those of the anterior branch of RLNs, respectively. The single-fasciculated PNs comprised of about 75.0% (18/24)).

CONCLUSION

Clinically, it may be safe and available for cutting PN off at the level of the subclavian vein. The length of PN is enough for the anastomosis of PN to the anterior branch of RLN.

Mobilization of the phrenic nerve in the thoracic cavity by video-assisted thoracic surgery. Techniques and initial experience

BACKGROUND

The use of video-assisted thoracic surgery (VATS) techniques to mobilize the phrenic nerve in the thoracic cavity for neurotization after brachial plexus injury was studied.

METHODS

From August 1999 to January 2000, 10 men and 1 woman with brachial plexus injury (left side in 5 and right side in 6) joined the study group. Their ages ranged from 20 to 38 years (average, 28 years). Supine after general anesthesia, all the patients had double-lumen trachea cannulas to guarantee complete lung collapse on the operative side. Three port incisions were made to allow introduction of the following: a 10-mm Stryker endoscope through the sixth intercostal space 2 cm medial to the anterior axillary line, one instrument for manipulation in the anterior axillary line of the third intercostal space, and another in the second intercostal space about 2 cm lateral to the parasternal line. The nerve was mobilized with two common long Mixter clamps and some endoscopic instruments by blunt and sharp dissection.

RESULTS

All patients were managed successfully without severe complications. The mean additional length of phrenic nerves by this technique was 16 cm.

CONCLUSIONS

Mobilization of the phrenic nerve by VATS is a safe and minimally invasive method for elongating the nerve for neurotization after brachial plexus injury.

Potential fascial dome made by the upper leaf of the phreno-esophageal membrane

We describe the configuration and size of the artificial fascial dome created in 57 cadavers. This dome protrudes into the thoracic cavity from the esophageal hiatus. This dome was a potential space realized by finger dissection (i.e., a specific but common surgical procedure during surgery of the upper part of the stomach). The vagus nerves penetrated the top of the dome and ran down along the esophagus. The height of the ventral wall of the dome ranged from 10-60 mm, while the dorsal wall was 10-40 mm longer than the ventral one since the dorsal wall attached to the lower, dorsal limb of the esophageal hiatus. Accordingly, the dorsal wall separated the "thoracic" aorta from the "abdominal" esophagus. We considered that the upper leaf of the phreno-esophageal membrane forms the fascial dome, although the lower leaf of the membrane was not identified in this study. According to the results, we proposed a schematic representation of the phreno-esophageal membrane.