Risk factors and follow-up of recurrent laryngeal nerve paralysis after first surgeries of benign thyroid diseases. Results of a retrospective analysis of 1,556 patients

PATIENTS AND METHODS: risk factors of recurrent laryngeal nerve (RLN) palsy after thyroid gland surgery were evaluated retrospectively in 1556 patients who were submitted to an operation because of a benign thyroid disease. Recurrences were also excluded. RESULTS: RLN palsy occurred in 6.6%. In relation to the nerves at risk the incidence of primary postoperative nerve damages was 4.3%. After a long-term follow-up of in total 18 months the incidence of permanent nerve palsy was 1.6% (related to the nerves at risk: 1.1%) as 75.5% of the paralyses were transient in an average of 6.2 months. Substernal goitres especially when sternotomy became necessary, the ligature of the inferior laryngeal artery, serious perioperative complications and total lobectomy in comparison to subtotal resection were important risk factors for primary postoperative RLN palsy (p < 0.05 resp. p < 0.01). The ligature of the inferior laryngeal artery and the extension of resection were indeed significant risk factors also for permanent nerve damages, but the other factors had no influence on the risk of permanent RLN palsy. However, the non-exposure of RLN in subtotal lobectomy was significantly associated (p < 0.01) with permanent, but not with transient nerve palsy. CONCLUSION: The exposure of the RLN is one of the most important procedures during thyroid surgery and particular also during subtotal lobectomy to reduce the rate of permanent RLN damages.     

Can total thyroidectomy be performed as safely by general surgeons in provincial centers as by surgeons in specialized endocrine surgical units? Making the case for surgical training

OBJECTIVE: To determine whether surgeons who had received appropriate training in the technique of total thyroidectomy could continue to perform the procedure with minimal morbidity after moving to a provincial surgical practice. DESIGN: Comparison of the complication rates from total thyroidectomy between a specialized endocrine surgical unit and provincial centers. SETTING AND PATIENTS: Six hundred fifty patients undergoing total thyroidectomy by two surgeons over a 5-year period in the endocrine surgical unit at Royal North Shore Hospital, St Leonards, Australia, were compared with 120 patients undergoing total thyroidectomy by seven provincial surgeons who were former trainees in the unit. MAIN OUTCOME MEASURES: Indications for surgery and specific complications of thyroidectomy including recurrent laryngeal nerve palsy, permanent hypoparathyroidism, and postoperative bleeding. RESULTS: Each of the seven surgeons in provincial practice performed only between two and 16 thyroidectomies annually. The percentage of total thyroidectomies for benign and malignant disease was identical for both the endocrine surgical unit and provincial center groups (44%). There was no difference in the incidence of recurrent laryngeal nerve palsy, permanent hypoparathyroidism, or postoperative bleeding between the two groups. CONCLUSION: Total thyroidectomy is an operation that always engenders controversy relating to the morbidity of recurrent laryngeal nerve and parathyroid injury. Surgeons who have completed a well-designed training program and who have become proficient at total thyroidectomy as trainees will remain proficient at the procedure despite practicing in a provincial center. Achieving a low morbidity rate demands meticulous attention to operative technique and anatomical detail.     

Recurrent laryngeal nerve paralysis after thyroid gland operations. Etiology and consequences]

In the period of 1 January 1990 to 31 December 1996 the thyroidectomy cases we performed were immediately followed by vocal cord evaluation using a flexible bronchoscope while the patient was still on the operating table. If an obvious cord paralysis was discovered, an exploration of the recurrent laryngeal nerve, to the level of the larynx, was performed. If the nerve was found to be intact, no further measures were taken. A severed nerve underwent suture repair. If an otolaryngologist diagnosed a vocal cord paralysis 1-5 days after surgery, a reoperation was recommended except in the cases where postoperative bronchoscopy had shown an easily mobile cord or the recurrent nerve was completely dissected during the operation. Within this 7-year period, we performed 3492 thyroidectomy operations. The diagnosis of subsequent unilateral postoperative vocal cord paralysis occurred in 48 cases. In 33 of these cases the status of the nerve in the surgical field was known: 4 patients had an intact nerve proved by complete dissection during thyroidectomy, in two patients the lesions of the nerve were detected intraoperatively (1 transsection, 1 partial resection), and 27 cases were followed by reoperation. Of the 33 patients mentioned above, in 19 instances the recurrent laryngeal nerve was found to be intact; 3 displayed signs of local trauma, and 11 were found to be severed with total discontinuity. Those patients with an intact nerve, or local nerve trauma only, went on to develop normal function within 6 months in 20 (91%) of 22 cases. Of the 11 with a severed nerve, 8 showed "autoparalysis" with good voice within 4-8 months, after suture repair in 10 cases. The patient with partial resection had no repair of the nerve. If immediate postoperative evaluation showed mobility of the vocal cords but a paralysis was detected later by an otolaryngologist and repeat intervention was not done, vocal cord function was spontaneously restored in 9 of 11 patients. Four patients refused reoperation. From 1990 to 1991, the recurrent laryngeal nerve was not always dissected during our thyroidectomy operations. However, this was done routinely from 1991 to 1996. Routine intraoperative dissection of the vocal cord nerve reduced the rate of postoperative cord paralysis from 2.0% to 1.2%. It also reduced the frequency of intraoperative nerve injury with total discontinuity from 0.58% to 0.23%.     

Autologous blood transfusion

BACKGROUND: The clinical significance of lymph node involvement along the recurrent laryngeal nerves in cancer of the thoracic esophagus is still controversial. Although these lymph nodes are anatomically located in a well-defined compartment (proximal mesoesophagus), appropriate procedures for dissecting them are not well established. STUDY DESIGN: We retrospectively investigated clinical results over the past 10 years in 276 patients who underwent systematic dissection of cervical, mediastinal, and upper abdominal lymph nodes. We routinely performed the cervical procedure before thoracotomy for total dissection of the proximal mesoesophagus and to minimize the operative risk. RESULTS: All macroscopically recognizable lesions were resected in 94% of the patients. The hospital mortality rate was 2.5%. Recurrent nerve palsy developed in 59 patients, but it was successfully managed without prolonged hoarseness in 50 of them. The recurrent nerve node group was most frequently involved (frequency of 25% in superficial cancer, 57% in non-superficial cancer). Supradiaphragmatic lymph node involvement was limited to the recurrent nerve nodes in 25% of the patients with positive supradiaphragmatic node. The 5-year survival rate in patients with positive recurrent nerve nodes was 34%. CONCLUSIONS: Dissection of the recurrent nerve lymph nodes is essential for curative esophagectomy even in the early phase of cancer invasion. Our cervicothoracic approach for total dissection of the proximal mesoesophagus yielded acceptable outcomes.     

Asthma mortality in New Jersey residents

We report an 11-year-old boy with active Epstein-Barr virus (EBV) infection who developed acute aphonia and had signs and symptoms of recurrent laryngeal nerve palsy. The association of isolated recurrent laryngeal nerve palsy and EBV infection has not previously been reported. This case report expands the spectrum of neurologic complications of EBV infection, and suggests that infectious mononucleosis should be considered in the differential diagnosis of acute aphonia in children.     

Small mammal populations and community under conditions of extremely high thallium contamination in the environment

BACKGROUND: The goal of this study was to evaluate the safety and efficacy of total thyroidectomy performed for benign thyroid disease. METHODS: A total of 106 consecutive patients undergoing total thyroidectomy for benign disease from October 1982 to July 1995 were reviewed. The 33 men and 73 women had an average age of 46 years (range, 16 to 82 years). Indications for total thyroidectomy were a thyroid nodule with the history of head and neck radiation in 36 patients, bilateral thyroid nodules in 35, needle biopsy of a follicular neoplasm or frozen section diagnosis of a possible malignancy in 18, and toxic goiter in 17. Total thyroidectomy was performed as the primary operation in 98 patients, and 8 patients had a completion reoperation for recurrent disease. RESULTS: Pathology findings revealed benign nodular goiter in 49 patients, follicular adenoma in 26, hyperplasia in 19, and Hashimoto's thyroiditis in 12. Postoperative hemorrhage requiring operative hemostasis occurred in two patients (1.9%). Two patients had unilateral recurrent laryngeal nerve (RLN) palsy before operation (1.9%). Three patients had unilateral postoperative RLN palsy (2.8%). Two cases resolved in 3 and 4 months. The only permanent RLN injury occurred in a patient reoperated for a compressive goiter. Early postoperative hypocalcemia (8.0 mg/dl or less) was found in nine patients (8.5%). No patient had permanent hypoparathyroidism at long-term follow-up evaluation. CONCLUSIONS: Total thyroidectomy for benign thyroid disease can avoid reoperation for nodular goiter and hyperthyroidism and eliminate any subsequent risk of malignant change in radiated thyroid glands. A low complication rate can be achieved with meticulous surgical technique. Total thyroidectomy can be performed safely for bilateral benign thyroid disease.     

Surgical treatment of Graves' disease in patients younger than 18 years

Eighty-two children and adolescents (18 males, 64 females; median age 14 years) surgically treated for Graves' disease at a single institution between 1979 and 1993 were retrospectively reviewed. Most of the patients (74%) coming to thyroidectomy had been treated medically for a period ranging from 2 to 80 (median 15) months. Bilateral subtotal thyroid resection was the most frequently performed procedure (86%). Postoperatively, no permanent recurrent laryngeal nerve palsy or permanent hypocalcemia occurred. Operative mortality was zero. With a median follow-up of 8.3 years, recurrent hyperthyroidism occurred in five patients (6%), one of whom required reoperation. Most children and adolescents with Graves' disease can be rendered euthyroid by nonsurgical treatment options. However, prolonged and ineffective medical treatment should be avoided in these patients who are in the formative years of their lives. Surgical treatment, when indicated and employed, offers young patients with Graves' disease a safe, rapid, definitive, cost-effective treatment with a high success rate.     

Swallowing performance in patients with vocal fold motion impairment

Twenty-seven patients with vocal fold motion impairment underwent detailed pharyngoesophagel manometry with a strain gauge assembly linked to a computer recorder. Nine were known to have lesions of the central vagal trunk or nucleus, 9 had recurrent laryngeal nerve (RLN) palsy, and the remainder were idiopathic. The site of the lesion was a more important determinant of subjective swallowing performance than the position of the involved cord at laryngoscopy. Patients with central lesions had lower tonic and contraction upper esophageal sphincter (UES) pressures than 25 age-matched controls, suggesting that high cervical branches of the lower cranial nerves are important in UES excitatory innervation. RLN palsy patients showed significantly increased pharyngeal contraction amplitude and reduced pharyngoesophageal wave durations. The results suggest that the dysphagia associated with vocal fold motion impairment is not simply due to the disruption of laryngeal deglutitive kinetics, but to independent effects on pharyngeal function.     

Ortner's syndrome: a centenary review of unilateral recurrent laryngeal nerve palsy secondary to cardiothoracic disease

Ortner's Syndrome (described 100 years ago in 1897) is a clinical entity with hoarseness due to a left recurrent laryngeal nerve (LRLN) palsy caused by cardiac disease. A 35-year-old woman presented with a LRLN palsy due to a huge thoracic aneurysm. The anatomy of the LRLN and the cardiothoracic complaints which may cause the palsy are discussed.     

Heterogeneity of clonal development in chronic myeloproliferative disorders

A 4-kg male child, born at 34 weeks to a gestational diabetic mother, had a large ductus arteriosus aneurysm causing phrenic and recurrent laryngeal nerve palsies and large airway compression. The right and left atrial appendages and distal descending aorta were cannulated, allowing left heart partial or complete cardiopulmonary bypass as necessary. On bypass the ductus was ligated, decompressed, and oversewn but not excised. Examination 1 month later suggested resolution of the recurrent laryngeal palsy and echocardiography showed regression of the aneurysm. Ductus ligation and decompression was an effective surgical treatment, which is less likely to cause complications than resection.     

Vocal cord laterofixation as early treatment for acute bilateral abductor paralysis after thyroid surgery

Bilateral vocal cord palsy due to a lesion of the recurrent laryngeal nerves is a serious complication of thyroid operations, with the airway obstruction usually necessitating tracheostomy. In the cases presented, a stable airway was ensured with endolaryngeal cord laterofixation instead of tracheostomy. The operation was performed with the endo-extralaryngeal needle carrier instrument devised by Lichtenberger. During the operation, only minor surgical trauma occurred in the larynx. The fixing thread was then removed following recovery of contralateral vocal cord function, resulting in an improvement in the voice. Four patients are described who suffered bilateral recurrent laryngeal nerve palsy after thyroid gland operations. During the follow-up period of 3-12 months, airway stability was demonstrated by regular spirometric measurements. The simple method recommended spares patients the possible complications of tracheostomy.     

Primary hyperthyroidism 1996

55 prospectively documented patients aged 20-84 (median 67) years (47 women, 8 males) underwent surgery for primary hyperparathyroidism (pHPT). The most frequent symptoms and associated conditions were nephrolithiasis (42%) and neuropsychiatric symptoms (39%). Only one case of asymptomatic and one case of "normocalcemic" pHPT were found in this series. 47 patients (89%) were cured following initial neck exploration, and 3 further patients (6%) were cured by a second operation. Reoperation also led to cure in 2 patients operated on elsewhere in the first instance. 6 patients (11%) had double adenoma (bilaterally) and 36% of the adenomas had an ectopic location, with an intrathyroidal adenoma in 2 cases. In 2 patients sternotomy was carried out. Persistent pHPT was observed in 3 patients (following initial exploration in 2 cases and reoperation in one). These patients had a supernumerary adenomatous gland with ectopic location in 2 cases and a double adenoma with ectopic position of one adenoma in a further case. One 80-year-old patient died post-operatively from intestinal ischemia. 2 patients had permanent postoperative hypoparathyroidism; in no case was a permanent recurrent laryngeal nerve palsy observed. Bilateral parathyroid exploration with thyroid mobilization by capsular dissection is the procedure of choice for pHPT. In 2 patients with the MEN 2A-syndrome and with medullary thyroid carcinoma thyroidectomy, lymphadenectomy and autotransplantation of normal parathyroids to the arm was performed, with normal parathyroid function in both cases.     

Overexpression of CAF1 encoding a novel Ca2+-binding protein stimulates the transition of Dictyostelium cells from growth to differentiation

In Mexico, 39% of 158 patients operated on for thyroid cancer require reoperative thyroid surgery. We retrospectively reviewed the indications and histopathological findings of 60 patients reoperated on because of: a) suspected persistent or recurrent disease; b) high risk patients treated by lobectomy; c) different histology; d) complete lack of information, e) and distant metastasis. In 53 cases (88%), the initial surgery was nodulectomy or lobectomy, and in seven (11%) was subtotal or near-total thyroidectomy. Among the 60 reoperations, 50 were completion total thyroidectomy and 10 were near-total thyroidectomy. In 27 cases (45%) a neck dissection was additionally done. Histologic examination revealed thyroid carcinoma in 32 cases (53%) and neck node metastasis in 28 cases (47%). Complications included six cases (9%) of permanent palsy of the recurrent laryngeal nerve after the initial surgery outside of our hospital and two cases (1.75%) of reoperated cases. In four reoperated patients (6.6%), permanent hypoparathyroidism was developed. It is mandatory to complete thyroidectomy and neck dissection in a high proportion of patients initially treated in general hospitals due to an inadequate criteria in the selection of the extension of thyroidectomy and treatment of neck node metastases. Histologic findings of these patients support our indications to complete the surgical treatment.     

Differences between left- and right-hand reaction time rhythms: indications of shifts in strategies of human brain activity

Surgery for symptomatic hyperparathyroidism remains the standard therapy. Asymptomatic primary hyperparathyroidism (pHPT) is being diagnosed with increasing frequency owing to broad serum testing. Indications for surgery in this setting are controversial. For evaluation of surgical safety we performed a retrospective analysis of our patients who were being operated on for asymptomatic pHPT. From January 1988 until August 1995, 243 patients were treated for pHPT and registered prospectively at our unit. Seventy-six patients were classified as asymptomatic. In all, 75% of the patients were female; the mean age was 62 years. In this group, 87% of the patients had cervical sonography in order to localize the adenoma. Highly selective venous catheterization was required in cervical reexplorations. Statistical analysis for potential prognostic factors for the clinical outcome was performed. Successful cervical exploration was possible in 71 patients (94.7%). With 4 patients remaining hypercalcemic, the rate of persistency was 5.2%. Localization procedures were correct in 58% for cervical ultrasound and 77% for selective venous catheterization. Postoperative morbidity included one permanent recurrent laryngeal nerve palsy and 2 patients with hemorrhage who were treated by reoperation. While one case of permanent hypoparathyroidism was well controlled by oral supplementation, 18 patients recovered from temporary hypoparathyroidism. No postoperative mortality occurred. Risk factor analysis revealed only cervical reexplorations for HPT to be associated with a higher morbidity (P = 0.02). Surgery for asymptomatic pHPT can be performed with reasonable safety. Cervical reexplorations in asymptomatic patients should be reserved for special indications. Apart from this small group, all patients should be evaluated for surgery.     

A novel procedure for mediastinal vagotomy inhibits neurogenic inflammation in rat bronchial tree

Tachykinin-containing sensory axons originating from the cervical vagal nerves and the first several pairs of thoracic spinal nerves are involved in neurogenic inflammation evoked by capsaicin in the bronchial tree. Unilateral degeneration of the cervical vagal trunk by surgical lesion inhibits neurogenic inflammation in the ipsilateral bronchial airways. The vagal trunk has two main branches, the thoracic vagus nerve and recurrent laryngeal nerve in the thorax. The main purpose of this study was to determine whether the thoracic vagus nerve or recurrent laryngeal nerve was significantly involved in the neural control of bronchial inflammation in the rat. A novel and safe surgical procedure was used for selectively cutting the right thoracic vagal trunk, thoracic vagus nerve, or recurrent laryngeal nerve by introducing the surgical instrument through an aperture between the first and second ribs in the ventral wall of the rostral mediastinum. This surgical operation could be completed without causing a pneumothorax. After 2 postoperative weeks, the effects of denervation on capsaicin-induced plasma extravasation in the respiratory tract were tested. Either right thoracic vagal trunk transection or thoracic vagus section significantly decreased plasma extravasation in the right bronchial tree. Thoracic vagus section was obviously more effective. Evans blue extravasation in the right lobar bronchi was reduced by 44-78% after thoracic vagal trunk transection, while that in the right mainstem and lobar bronchi was reduced by 58-81% after thoracic vagus section. Area densities of India ink-labeled leaky blood vessels in the right lobar bronchi were reduced by 40-65% after thoracic vagal trunk transection, and those in the right mainstem and lobar bronchi were reduced by 83-88% after thoracic vagus neurectomy. Recurrent laryngeal neurectomy did not change the plasma extravasation induced by capsaicin in the trachea and bronchi. These results suggest that capsaicin-sensitive fibers running in the vagal trunk, which largely mediated neurogenic inflammation in the bronchial tree, were projected into the thoracic vagus nerve which, in turn, sent these nerve fibers to the ipsilateral bronchial tree. For the trachea, the remaining sensory fibers surviving denervation might provide sufficient tachykinins to trigger neurogenic inflammation.     

Stapedial reflex: a biological index found to be abnormal in clinical and subclinical hypothyroidism

INTRODUCTION: Parathyroidectomy via cervical exploration is an effective primary-modality treatment for hyperparathyroidism, with cure rates of greater than 95%. We retrospectively reviewed 866 consecutive parathyroidectomies performed by a single surgeon between 1960 and 1997. We attempted to describe the polymorphic variation in multiglandular disease, the anatomic locations of pathologic glands, and the operative strategy and techniques which we believed were important to minimizing morbidity and maximizing curative success. METHODS: The cases of 329 males and 537 females (age, 1-88 years) were reviewed. There were 766 operations performed: primary hyperparathyroidism (713), tertiary hyperparathyroidism (100), reoperations (53). The strategy for primary exploration includes a bilateral neck exploration, early recurrent laryngeal nerve skeletonization, and identification of at least four glands. RESULTS: Normocalcemia was achieved in 98.2% of cases after initial cervical exploration. Persistent hypercalcemia occurred in 7 patients (<1%). Nine patients (1%) suffered persistent postoperative hypocalcemia. Unilateral recurrent laryngeal nerve injury occurred in two patients (<1%). Other perioperative complications included: reoperation for hematoma, repaired carotid artery injury, unexplained dysphagia, pneumothorax, deep venous thrombosis, and aspiration pneumonia. There were two mortalities (<1%) attributable to severe, comorbid disease. Ectopic glands were found in 120 cases. The frequency of glands at these sites were as follows: mediastinal (4.9%), intrathymic (8.4%), intrathyroid (6.7%), and retroesophageal/retrotracheal (3.5%). Thyroid resections provided diagnosis of concomitant thyroid carcinoma in 8.0% of resected patients. The pathology of patients with primary hyperparathyroidism (PHPT) consisted of single adenomas (77.2%), hyperplasia (21.0%), normal glands (1%), double adenomas (<1%), and parathyroid carcinoma (<1%). The distribution of adenomas was as follows: left upper, 25.3%; left lower, 27.3%; right upper, 26.8%; right lower, 20.6%. Hyperplastic glands were found in ectopic positions as follows: intrathymic (7.5%), intrathyroid (11.3%), mediastinal (2.5%), and retroesophageal/retrotracheal (0%). The average volume difference between the largest and smallest hyperplastic gland of each case was 1.80 + 4.40 cm3. Reoperations were performed upon 53 referred patients and 7 patients after failed exploration. Normocalcemia was attained in 98.3% of cases. Glandular pathology was identified in the previous operative field in 52 patients (86.7%). Adenomas were identified in 56.0% (n = 23) and hyperplasia in 39.0% (n = 16). CONCLUSIONS: In our series, we were able to attain normocalcemia in 98.2% of cases after initial cervical exploration. We believe that identification of four glands, an exhaustive search of ectopic sites, bilateral exploration, and liberal use of biopsy and intraoperative frozen section were essential to curative success. The pathologist should identify parathyroid tissue in the specimen and differentiate the "abnormal" from "normal" gland. Morphologic criteria alone cannot be used because of polymorphic variation in hyperplasia in which pathologic glands may appear normal. Early identification of the recurrent laryngeal nerve allows for a safer neck exploration by alerting the surgeon to the location and course of the nerve. A bilateral approach does not contribute increased morbidity from recurrent laryngeal nerve injury.     

Nonrecurrent recurrent nerve. Danger in thyroid and parathyroid surgery. Apropos of 9 cases

Main difficulties in thyroid surgery are represented by recurrent nerve anatomy and parathyroid glands. Nerve injury or accidental truncation cause definitive impairment. Risk of recurrent paralysis is 0.5 to 3% for advanced teams. Early investigation and dissection of this nerve are considered mandatory for preservation. This practice is also highly indicated due to anatomical variations, cause for accidental truncation. The most difficult case is encountered when there is nerve non recurrence, due to variations in origin and path of the nerve. Inferior laryngeal nerve non recurrence can be present on the right side, it is uncommon but possible on the left side. We have evaluated a series of 1165 cervicotomies undertaken for thyroidectomy or parathyroid gland approach. There were 9 cases of non recurrence. Literature review allowed us to study anatomical variations and nerve relationships.     

Unusual metastasis of hypernephroma in the maxillary sinus

OBJECTIVES: To determine the predictive value of intraoperative threshold stimulus for facial nerve outcome and the prevalence and prognostic value of persistent trains of activity and frequent spontaneous or mechanically induced contractions during acoustic neuroma surgery. STUDY DESIGN: Prospective recording and subsequent review of facial nerve activity. SETTING: Tertiary referral centre. PATIENTS AND METHODS: Consecutive patients undergoing acoustic neuroma surgery. Intraoperative facial nerve activity was digitised and stored on a personal computer for future analysis. Operative events were flagged. Recordings were available in 27 patients. MAIN OUTCOME MEASURES: Frequent mechanically induced contractions (< 20), prolonged trains of facial nerve activity (total time > 199 seconds), and facial nerve brainstem stimulus threshold were correlated with facial nerve outcome. RESULTS: A brainstem stimulus threshold > 0.1 mA was significantly associated with intermediate or poor facial nerve function (House-Brackmann grade > 2) on the sixth postoperative day, at 1 month and 6 months. Patients with normal or near-normal facial function on the first day and a threshold of > 0.1 mA were significantly more likely to develop a delayed facial nerve palsy. Frequent contractions were noted in 74% of patients and persistent train activity in 59%. Neither was predictive of facial nerve outcome. CONCLUSIONS: An elevated brainstem threshold is helpful in predicting delayed facial nerve palsy and suboptimal facial nerve outcome. Persistent train activity and frequent contractions, do not have major prognostic significance.     

Interscalene brachial plexus catheter for anesthesia and postoperative pain therapy. Experience with a modified technique

OBJECTIVES: This study was conducted to evaluate a modified technique of interskalene brachial plexus anaesthesia (ISB) and postoperative catheter analgesia for shoulder surgery. The original method described by Winnie bears some rare but life-threatening complications (inadvertent subarachnoid or intra-arterial injection, pneumothorax). MATERIALS AND METHODS: Ninety-one patients with chronic rheumatoid arthritis who were scheduled for open or closed shoulder surgery received a modified ISB with catheter insertion. The injection site was more cephalad than that described by Winnie and the cannula was directed towards the junction between the medial and lateral third of the clavicle. Intra- and postoperative management, complications, and patients' satisfaction were recorded and evaluated. RESULTS: Implementation of ISB was possible in all cases, however, 3% of these presented technical problems. Anaesthesia with 300 mg mepivacaine 1% was successful in 94% of patients without and in 96% with augmentation after an average of 32 min; 10% of the patients suffered a drop in blood pressure after being placed in the beach-chair position for surgery. Postoperatively, all patients received 20 ml bupivacaine 0.25% for pain management via the catheter; 11% needed an additional analgesic drug. The catheter was removed after an average of 5 days. Signs of superficial local infection were noticed in 8 cases. Side effects occurred in 13% as Horner's syndrome, in 6.5% as recurrent laryngeal nerve block, and in 3.3% as phrenic nerve block. The acceptance of this anaesthetic technique among the patients was very high (96.7%). CONCLUSION: We consider the modified ISB with catheter a safe and effective procedure for anaesthesia and postoperative pain management of open and closed shoulder surgery.     

Long-term model of induced canine phonation

Experimental induced phonation in the dog has been used in short-term studies by several investigators and has proved quite useful in laryngeal research. In this study a long-term canine phonation model is described that uses permanently implanted electrodes on the superior and recurrent laryngeal nerves. A serial induced phonation model has not been previously reported and is needed for laryngeal research in which voice results are a primary end point. Inexpensive, reliable, nontoxic electrodes were designed and fabricated. The laryngeal nerves were found to be quite susceptible to injury, necessitating a series of changes in electrode design. Electrode durability and laryngeal nerve viability improved with each design modification; the final design gave a recurrent laryngeal nerve viability rate of 100% at 6 weeks, 83% at 9 weeks, and 73% at 12 weeks. Induced phonation was successfully produced on a repeated basis by stimulating the recurrent laryngeal nerves while passing air through the larynx, in 22 (95.6%) of 23 animals. Stimulation of the superior laryngeal nerves increased vocal fold length and tension but was not required for phonation. Technical aspects of chronic implantation and stimulation of the laryngeal nerves are discussed. The development and successful long-term implantation of electrodes on the laryngeal nerves and their use in repeated induced phonation have not been reported previously.