Transient paralysis of the diaphragm following radical neck surgery

The phrenic nerve; the forgotten nerve in head and neck surgery

BACKGROUND

Neck dissection is a commonly performed procedure for oncologic control of head and neck malignancy. With contemporary modified radical and selective neck dissections, haematoma, wound infection, tissue necrosis, chyle leak and injury involving the marginal mandibular, hypoglossal, vagus or accessory nerves are commonly described complications. Although the phrenic nerve courses within the surgical planes explored during a neck dissection and has a vital function in innervating the diaphragm, few studies have been performed to investigate the exact incidence of post-operative phrenic nerve paresis. This study aims to review the literature as to the rate of phrenic nerve injury following neck dissection.

METHODS

A systematic literature review was conducted from 2000 to 2022 including studies reporting on phrenic nerve paresis following neck dissection.

RESULTS

In total, 11 studies were included. The reported rate of immediate post-operative phrenic nerve paresis ranged from 0% to 5.3%, with an average rate of 0.613% (12/1959). The reported rate of phrenic nerve paresis at follow-up (1 month-127 months) ranged from 0% to 4.7%, with an average rate of 1.035% (5/483). There were no cases of bilateral phrenic nerve paresis reported in this period.

CONCLUSIONS

Phrenic nerve paresis is an uncommon complication following neck dissection, often asymptomatic and potentially underreported. Bilateral phrenic nerve paresis is exceedingly rare. Injury can be avoided by staying superficial to the prevertebral fascia when dissecting around the anterior scalene muscle. Routine phrenic nerve integrity monitoring is not commonly utilized but may aid intra-operative phrenic nerve identification or confirmation of function.

Phrenic Nerve Palsy in Severe Tetanus

Unilateral or bilateral raised hemidiaphragms were observed on chest X-ray in three patients with severe tetanus. Diaphragmatic movement was absent on ultrasonography and fluoroscopy. Nerve conduction study confirmed phrenic nerve palsy. Bilateral involvement caused delayed weaning from the ventilator, whereas unilateral involvement was asymptomatic. There was complete recovery from phrenic nerve palsy in all patients.

Inspiratory muscle weakness, diaphragm immobility and diaphragm atrophy after neck dissection

BACKGROUND

Inspiratory strength after a neck dissection has not been evaluated, and diaphragm function has not been adequately evaluated.

OBJECTIVE

Evaluate diaphragm mobility and inspiratory strength after neck dissection.

METHODS

Prospective data collection of a consecutive series of adult patients submitted to neck dissection for head and neck cancer treatment, in a tertiary referral cancer center, from January to September 2014, with 30 days of follow-up. A total of 43 were studied (recruited 56; excluded 13).

MAIN OUTCOME MEASURES

Determine diaphragm mobility and inspiratory muscle strength after neck dissection, using diaphragm ultrasound and by measuring maximal inspiratory pressure (MIP) and sniff nasal inspiratory pressure (SNIP).

RESULTS

Thirty patients underwent unilateral neck dissection, and thirteen patients underwent bilateral neck dissection. Diaphragm immobility occurred in 8.9% of diaphragms at risk. For the entire cohort, inspiratory strength decreased immediately after the dissection but returned to preoperative values after 1 month. Except for those with diaphragm immobility, diaphragm mobility remained unchanged after the dissection. One month after the dissection, the diaphragm thickness decreased, indicating diaphragm atrophy.

CONCLUSIONS

Immediately after a neck dissection, just a few patients showed diaphragmatic immobility, and there was a transient decrease in inspiratory strength in all individuals. Such findings can increase the risk of postoperative complications in patients with previous lung disease.

Diaphragm Dysfunction: Diagnostic Approaches and Management Strategies

The diaphragm is the main inspiratory muscle, and its dysfunction can lead to significant adverse clinical consequences. The aim of this review is to provide clinicians with an overview of the main causes of uni- and bi-lateral diaphragm dysfunction, explore the clinical and physiological consequences of the disease on lung function, exercise physiology and sleep and review the available diagnostic tools used in the evaluation of diaphragm function. A particular emphasis is placed on the clinical significance of diaphragm weakness in the intensive care unit setting and the use of ultrasound to evaluate diaphragmatic action.

Selective resection of the phrenic nerve roots in rabbits. Part II: Respiratory effects

This study evaluates the delayed respiratory consequences of selective resection of one or several roots of the right phrenic nerve in rabbits. A total of 50 animals were operated on according to five modalities of root resection. A total of 11 animals served as control. The breathing pattern was analysed 8 weeks after surgery. Transdiaphragmatic pressure was measured during transjugular supramaximal stimulation of the phrenic nerve, unilaterally or bilaterally and during prolonged tracheal occlusion (PImax). No difference was observed between the esophageal pressure observed during bilateral phrenic nerve stimulation (BilPeso) in control animals when compared to animals with resection of the highest root of the right phrenic nerve (16.2 +/- 1.0 versus 14.5 +/- 1.0 cmH2O (mean +/- SE). Resection of the two highest or of the two lowest roots of the right phrenic nerve resulted in a similar BilPeso (11.3 +/- 0.8 versus 11.1 +/- 1.2 cmH2O). Preservation of only the accessory phrenic nerve (PN) resulted in a low value of BilPeso (9.8 +/- 1.0 cmH2O) similar to that obtained with complete denervation of the right hemidiaphragm. Ventilation and PImax were not different between the denervated or intact rabbits during quiet breathing. We conclude that in rabbits: (1) Diaphragmatic function is preserved after resection of the highest root of the phrenic nerve. (2) Diaphragmatic function is altered if only the APN is preserved.

Selective resection of the phrenic nerve roots in rabbits. Part I: Cartography of the residual innervation

Partial unilateral diaphragmatic paralysis remains poorly understood. This study evaluates the residual innervation of the diaphragm after selective resection of one or several roots of the right phrenic nerve in rabbits. Forty-seven animals were operated on according to five root resection modalities. Seven animals served as control. Eight weeks after surgery, the different regions of each hemidiaphragm were analyzed. Electromyographic activity was measured during quiet inspiration and the following histomorphometric parameters were studied: mean fiber area, fiber area dispersion, and ratio large diameter over small diameter. The results obtained from the two measurements were similar. When the accessory phrenic nerve was spared, the crural diaphragmatic region was preserved; denervation was encountered in anterior and lateral parts of the hemidiaphragm. When the highest root of the right phrenic nerve was resected, denervation denervation was limited to the sternal region. When resection of the two highest roots was performed, partial denervation was observed in each region, with residual innervation in the posterior hemidiaphragm. When resection of both the lowest roots was performed, denervation was maximal in the costal region; sternal region remained intact. No contralateral innervation was observed. We conclude that in rabbits: 1) resection of a single root of the phrenic nerve preserves consistent residual innervation. 2) somatotopy of the diaphragm innvervation follows an anteroposterior distribution.

Bilateral phrenic nerve injury after neck dissection: an uncommon cause of respiratory failure

The case of a patient with carcinoma larynx who developed diaphragmatic paralysis and post-operative respiratory failure due to bilateral phrenic nerve injury is reported. The use of portable ultrasonography for an early diagnosis of diaphragmatic paralysis is discussed.

Phrenic nerve injury following scalenectomy in a patient with thoracic outlet obstruction

We present a case in which a patient with normal pulmonary reserve experienced orthopnea and hypoxia secondary to unilateral diaphragmatic paralysis following right scalenectomy. This operation was performed in an attempt to relieve neurovascular compromise at the thoracic outlet. To our knowledge, this association has not been previously described in the literature.

Phrenic nerve paralysis following neck dissection

One of the complications of neck dissection to control regional metastatic disease in cancer of the head and neck is phrenic nerve paralysis. The resulting elevation of the ipsilateral diaphragm can be diagnosed on a postoperative chest X-ray and confirmed by fluoroscopy. Symptoms can be respiratory, cardiac or gastrointestinal. In a retrospective study, unilateral phrenic nerve paralysis was observed in 14 (8%) of 176 consecutive neck dissections. None of the patients with postoperative phrenic nerve paralysis displayed severe symptoms, although a significantly higher number sustained atelectasis with or without pulmonary infiltrates to complicate the postoperative course.

Paralysis of the hemidiaphragm as a complication of internal jugular vein cannulation: report of a case

A case of phrenic nerve injury following cannulation of the internal jugular vein is presented. Considering the close relation between the phrenic nerve and the internal jugular vein, one should be aware of the possibility of phrenic nerve injury with an increase in the number of attempts at cannulation.