Detection of African swine fever virus in free-ranging wild boar in Southeast Asia.

African Swine Fever (ASF) is a highly contagious and fatal viral disease affecting both domestic and wild suids. The virus was introduced to Southeast Asia in early 2019 and has since spread rapidly throughout the region. Although significant efforts have been made to track and diagnose the disease in domestic pigs, very little is known about ASF in free-ranging wild boar and their potential role in maintaining the disease within Southeast Asia. Through a collaboration between government and non-government actors in Laos, Viet Nam, and Cambodia, investigations were conducted to (a) characterize the interface between domestic pigs and wild boar, (b) document risk factors for likely ASF spillover into wild boar populations by way of this interface, and (c) determine whether ASF in wild boar could be detected in each country. An extensive overlap between wild boar habitat and domestic pig ranging areas was found around villages bordering forests in all three countries, creating a high-risk interface for viral spillover between domestic pig and wild boar populations. Fifteen and three wild boar carcasses were detected through passive reporting in Laos and Viet Nam, respectively, in 2019 and early 2020. Four of five carcasses screened in Laos and two of three in Viet Nam were confirmed positive for African swine fever virus using real-time PCR. There were no confirmed reports of wild boar carcasses in Cambodia. This is the first confirmation of ASF in wild boar in Southeast Asia, the result of a probable viral spillover from domestic pigs, which highlights the importance of early reporting and monitoring of ASF in wild boar to enable the implementation of appropriate biosecurity measures.

Impact of central node dissection on postoperative morbidity in pediatric patients with suspected or proven thyroid cancer.

BACKGROUND: Pediatric risk factors for postoperative morbidity after central node dissection are ill-defined. METHODS: This outcome study aimed to evaluate operative morbidity in patients aged ≤18 years after total thyroidectomy with or without central node dissection for suspected or proven thyroid cancer. RESULTS: Included were 102 patients with hereditary C-cell hyperplasia, 66 patients with medullary, 60 patients with papillary, and 2 patients with follicular thyroid cancer. In all 230 patients, 131 of whom underwent central node dissection, transient recurrent laryngeal nerve palsy was significantly associated only with central node dissection (100% vs 55%; P = .010). Transient and permanent hypoparathyroidism were significantly associated with age (means of 11.9 years versus 7.8 years, and 12.9 years versus 8.5 years; P ≤ .002); central node dissection (80% vs 50%, and 100% vs 54%; P ≤ .001); and the number of central lymph nodes cleared (means of 12.2 nodes versus 5.4 nodes, and 26.9 nodes versus 5.8 nodes, P < .001). These effects were stronger for permanent than transient hypoparathyroidism. Correlations between permanent hypoparathyroidism and the number of nodes cleared on central node dissection (r = 0.35) were closer than those between permanent hypoparathyroidism and age (r = 0.15), but similar for transient hypoparathyroidism (r = 0.22 and r = 0.25). CONCLUSION: Owing to the incremental morbidity from central node dissection, the extent of a neck operation, in experienced hands, should be tailored to the extent of the underlying disease regardless of the child's age. The notion that the experience of the center and surgeons may be more important than the age of the child requires validation in independent series across different health care settings.

Dynamics of loss and recovery of the nerve monitoring signal during thyroidectomy predict early postoperative vocal fold function.

BACKGROUND: The characteristics of segmental type 1 and global type 2 injuries to the recurrent laryngeal nerve (RLN) and the extent and dynamics of nerve recovery are poorly understood. METHODS: This investigation of 785 patients who underwent thyroidectomy under continuous intraoperative nerve monitoring aimed at exploring the dynamics of loss and recovery of the nerve monitoring signal and its relationship to early postoperative vocal fold palsy. RESULTS: Persistent complete loss of signal and signal recovery <50% identified all (based on 12 and 4 patients with type 1 injuries) or most (based on 9 of 12 and 4 of 6 patients with global type 2 injuries) early unilateral vocal fold palsies. Signal recovery ≥50% (based on 7 patients) always signified normal vocal fold function. CONCLUSION: These data, including the observation that global type 2 injuries may entail less severe nerve injury, require validation in independent series before being adopted more widely. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1144-E1151, 2016.

Minimally invasive compared with conventional thyroidectomy for nodular goitre.

Since minimally invasive thyroidectomy was introduced in 1997, different surgical approaches to the thyroid have been described: the minimal neck incision and the anterior chest, areolar breast or axillary access. Whereas conventional open thyroidectomy is suitable for any thyroid disease, minimal neck incision thyroidectomy or extracervical scarless neck thyroidectomy are limited to small-volume disease. In 11 prospective randomized studies and six systematic reviews, minimally invasive video-assisted thyroidectomy via a central or lateral neck approach afforded better cosmesis in the first 3 months than conventional open thyroidectomy, with less postoperative pain for the first 48 h. Surgical morbidity did not differ in these limited studies. No head-to-head comparison is available for extracervical scarless neck thyroidectomy and conventional open thyroidectomy. Extracervical scarless neck thyroidectomy caused more postoperative pain and gave rise to complications not seen with minimal neck incision thyroidectomy or conventional open thyroidectomy. In the absence of evidence to the contrary, conventional open thyroidectomy continues to remain the gold standard for any nodular goitre.

Continuous intraoperative vagus nerve stimulation for identification of imminent recurrent laryngeal nerve injury.

BACKGROUND: Conventional intraoperative nerve monitoring, predicated on intermittent stimulation, can predict recurrent laryngeal nerve (RLN) palsy only after the damage has been done. METHODS: Fifty-two patients (52 nerves at risk) who underwent continuous intraoperative nerve monitoring (CIONM) for thyroid surgery via vagus nerve stimulation had their electromyographic (EMG) tracings recorded and correlated with surgical maneuvers and postoperative RLN function. RESULTS: There was 1 imminent loss of signal (LOS) with intraoperative signal recovery and there were 4 losses of signal with corresponding unilateral transient RLN palsy. When EMG amplitude decreased >50% and EMG latency increased >10%, LOS and postoperative RLN palsy were noted in 4 of 8 patients (50%) who had multiple combined events. In 9 of 13 patients (70%) who developed adverse EMG changes, modification of the causative surgical maneuver resulted in recovery of those EMG changes and aversion of impending RLN palsy. CONCLUSION: CIONM reliably signaled impending nerve injury, enabling immediate corrective action.

Impact of extent of resection for thyroid cancer invading the aerodigestive tract on surgical morbidity, local recurrence, and cancer-specific survival.

BACKGROUND: The appropriate resection for thyroid cancer invading the aerodigestive tract remains controversial. METHODS: A total of 174 patients underwent resections for aerodigestive tract invasion from differentiated thyroid cancer (103 patients), medullary thyroid cancer (40 patients), and undifferentiated thyroid cancers/unusual thyroid neoplasms (31 patients). In all, 82 patients submitted to transmural resections (window resection, sleeve resection, or cervical evisceration), 65 patients underwent nontransmural resections (shaving or extramucosal esophageal resections), and 27 patients had grossly incomplete resections. The measures of outcome included surgical morbidity, locoregional recurrence, and disease-specific survival. RESULTS: Surgical morbidity was 38% after transmural and 25% after nontransmural resection (P = .02). On histopathologic examination, surgical margins were microscopically involved in 9% of patients after transmural and 23% of patients after nontransmural resection (P = .014). At a mean follow-up of 35.3 months, locoregional recurrence developed in 10 (46%) of 22 patients with microscopically incomplete and 18 (15%) of 121 patients with microscopically complete resection (P = .001). After grossly complete resection, the mean disease-specific survival was 101.2, 69.8, and 25.5 months for differentiated thyroid cancer, medullary thyroid cancer, and undifferentiated thyroid cancer/unusual neoplasms, respectively (P < .001). This outcome was independent of the type of resection. CONCLUSION: The type of cancer and resection are key determinants of outcome among thyroid cancer patients with aerodigestive tract invasion.

Limitations of intraoperative adrenal remnant volume measurement in patients undergoing subtotal adrenalectomy.

BACKGROUND: Recent studies have shown that a minimum of approximately one-third of one normal adrenal gland is required for sufficient adrenocortical stress capacity. Correlation between intraoperative measurement, determination of remnant size by computed tomography (CT), and adrenocortical stress capacity has not been examined so far. METHODS: Twenty-two patients with familial pheochromocytoma (n=13), sporadic pheochromocytoma (n=3), and adrenocortical tumors (n=6) who underwent unilateral or bilateral subtotal adrenalectomy (STAE, 28 adrenal remnants) were prospectively studied. Patients were examined in a multi-slice CT to determine residual adrenal tissue and by ACTH test 4 days and 3 months postoperatively. RESULTS: There was a slight significant correlation between intraoperative and CT calculated volumes (r=0.77; p<0.001). However, volumes assessed by CT were almost doubled compared with intraoperative determination (p<0.001). Although recovery of adrenal function could be observed, no significant changes of remnant volumes could be detected within 3 months. In patients with familial pheochromocytoma, there was a significant correlation between residual adrenal volume and stimulated cortisol levels (P<0.001). A distinct minimum of adrenal volume for intact adrenocortical stress capacity could not be exactly determined; however, in one patient with only 10% residual adrenal tissue intact stress capacity was found. CONCLUSIONS: Residual adrenal tissue of approximately 10-15% offers intact stress capacity. However, an exact determination of the size of an adrenal remnant after STAE has limitations. CT gives larger volumes compared with intraoperative determination. For calculation of a volume-function correlation of residual adrenal tissue, in clinical practice, the determination of relative adrenal residual volume is acceptable.

Riedel's thyroiditis: impact and strategy of a challenging surgery.

BACKGROUND: No surgical standard for Riedel's thyroiditis (RT) is established. Salvage surgery follows severe cervical and compressive airway symptoms or strong suspicion of malignancy. Obscured planes and multi-infiltrative extension prevent sufficient surgery with considerate complications. No alternative definitive treatment is available. In failing conservative treatment, the role of surgery in RT remains unclear. MATERIALS AND METHODS: Clinical manifestation, treatment, outcome and follow-up in a unique series of eight consecutive patients with RT are presented. RESULTS: Seven female patients and one male patient with cervical tumor growth or thyroiditis underwent four total and three sub-total thyroidectomies, respectively, one patient declined remedial surgery. Complications were one bilateral laryngeal nerve palsy and one transient hypoparathyroidism. Histology confirmed RT with perithyroidal extension and excluded malignancy in all. Symptomatic relief of cervical and airway obstruction was achieved in all. Follow-up revealed two extensive mediastinal RT recurrences 1 and 6 years after surgery. CONCLUSION: Favourable symptomatic outcome and alleviation of steroids in the majority render surgery for RT valuable when conservative treatment fails. However, more radical procedures show no advantages and recurrences are not prevented. The demanding technique in RT requires special surgical expertise and highly recommends intra-operative neuromonitoring.

Intra-operative quick insulin assay to confirm complete resection of insulinomas guided by selective arterial calcium injection (SACI).

BACKGROUND AND AIMS: Insulinomas are rare endocrine disorders. Pre-operatively, conventional imaging techniques often fail to localise the tumor. In addition, due to the lack of quick insulin assays, intra-operative confirmation of complete resection was impossible until recently. MATERIALS AND METHODS: Six patients with biochemical evidence of an insulinoma underwent pre-operative localisation studies and selective arterial calcium injection (SACI). In addition, insulin was measured before surgery and every 10-15 min after resection of the tumor using a quick insulin assay. RESULTS: Pre-operative localisation studies identified the tumor correctly as follows: endosonography: three of four, magnetic resonance imaging: two of four and SACI: six of six. Tumors in the head and body were enucleated while those in the tail were resected (n = 2, each). Those three patients, in whom magnetic resonance imaging and/or endosonography could localise the tumors pre-operatively, underwent laparoscopic surgery while the remaining three patients underwent open surgery. Intra-operatively, insulin dropped to normal levels within 20 min in all cases. After a follow-up of 0.8-3 years, all patients remained biochemically cured. CONCLUSIONS: Pre-operatively, SACI appears to be a very sensitive localisation technique and may be most helpful in guiding the surgeon if conventional imaging techniques fail to localise the tumor. Complete removal of an insulinoma can be reliably predicted using a quick insulin assay.

Long-term results and functional outcome after cervical evisceration in patients with thyroid cancer.

BACKGROUND: Surgical strategy in patients with thyroid cancer (TC) infiltrating the aerodigestive system is controversial. This study was undertaken to examine the long-term results of cervical evisceration (CE). PATIENTS AND METHODS: Since 1995, 14 consecutive patients with advanced TC underwent total laryngectomy (LE, n = 6) or esophagolaryngectomy (ELR, n = 8). Patients with unusual thyroid neoplasms or metastases to the thyroid (n = 3) were excluded. For esophageal reconstruction, free jejunal grafts (n = 6) and gastric tubes (n = 2) were used. RESULTS: Procedure-related morbidity and mortality were 42% and 14%, respectively. ELR was associated with a significant higher frequency of complications and reoperations compared with LE. Twelve-month and 30-month survival rates were 73% and 55%, respectively; 85% of the patients were satisfied with the surgical results. There were no long-term problems concerning food intake in the ELR patients. Two ELR patients were able to learn a substitutive voice. CONCLUSIONS: Cervical evisceration in patients with TC is associated with significant perioperative morbidity and mortality requiring careful patient selection. Regarding long-term survival, local tumor control, and patient's satisfaction, however, CE should be taken into account in suitable patients with advanced TC.

Codon-specific development of pheochromocytoma in multiple endocrine neoplasia type 2.

CONTEXT: Recent data suggest a codon-specific, age-related development of multiple endocrine neoplasia type 2. OBJECTIVE: The objective of this study was to delineate the codon-specific, age-related development of multiple endocrine neoplasia type 2-associated pheochromocytoma. DESIGN: We describe a cohort study with a mean observation period of 26.9 yr. SETTING: The study took place in a tertiary referral center at a university hospital. PATIENTS: Included in this study were 206 consecutive carriers (74 index, 132 nonindex) operated on at this institution who harbored point mutations in the RET (rearranged during transfection) protooncogene. INTERVENTION: The intervention was adrenalectomy for clinically confirmed pheochromocytoma. MAIN OUTCOME MEASURE: The main outcome measure was time to histopathological diagnosis of pheochromocytoma. RESULTS: Pheochromocytomas developed in 28% (five of 18) of carriers with mutations in codon 918, 29% (20 of 68) of carriers with mutations in codon 634, 14% (three of 21) of carriers with mutations in codon 618, 13% (two of 16) of carriers with mutations in codon 620, and 13% (two of 16) of carriers with mutations in codon 791. Earliest age of manifestation for each genotype was 22, 18, 29, 22, and 39 yr. Contralateral pheochromocytomas developed after 4 yr (one carrier each had a mutation in codon 618 or 620) and 5.2 yr (six carriers had mutations in codon 634). No pheochromocytomas were identified in carriers of mutations in codons 609 (n = 2), 611 (n = 8), 630 (n = 2), 768 (n = 8), 790 (n = 22), 804 (n = 18), and 891 (n = 7). CONCLUSIONS: Based on these and published preliminary data, annual screening for pheochromocytoma may be warranted from age 10 yr in carriers of RET mutations in codons 918, 634, and 630, and from age 20 yr in the remainder.

Timing and extent of surgery in patients with familial medullary thyroid carcinoma/multiple endocrine neoplasia 2A-related RET mutations not affecting codon 634.

In hereditary medullary thyroid carcinoma (MTC), recommendations regarding timing and extent of surgery are mainly based on the data of patients with the codon 634 RET mutation, which is the most often affected codon. Little is known about whether these recommendations may also be applied to patients with less common RET mutations. We ascertained the data from 140 patients with FMTC/MEN2A-related RET mutation not affecting codon 634 who have been treated at three specialized centers. The several RET mutations found affected codons 611 (n = 17), 618 (n = 22), 620 (n = 17), 768 (n = 9), 790 (n = 24), 791 (n = 21), 804 (n = 23), and 891 (n = 7). For each codon, the age of the youngest patient with MTC only (41, 7, 18, 29, 13, 47, 20, and 15 years, respectively), MTC with lymph node metastases (46, 24, 21, 34, 46, 47, 50, and 76 years, respectively), and MTC with distant metastases (52, 69, 43, 68, 57, - , - , and 75 years, respectively) was determined. All patients with lymph node metastases had elevated basal calcitonin levels. Based on these data, a more individual recommendation regarding timing and extent of surgery can be given. Because neither gender nor the type of nucleotide substitution for a specific codon appeared to have a significant influence on the age of onset, this recommendation should be based on the affected codon, the age of the patient, and the calcitonin level. Recurrent laryngeal nerve palsy (n = 6) and hypoparathyroidism (n = 3) were rather rare and were found only in patients older than 30 and 43 years, respectively, giving evidence that surgery in young patients can be performed safely.

Multiple endocrine neoplasia 2B syndrome due to codon 918 mutation: clinical manifestation and course in early and late onset disease.

More than 50% of patients with typical MEN-2B have a de novo M918T germline mutation of the RET protooncogene. However, even in typical MEN-2B, extrathyroidal manifestations of MEN-2B can be found to be differently expressed. We analyzed the clinical manifestation and course in 21 patients harboring a de novo RET M918T mutation. Mean age at MEN-2B diagnosis was 14.2 years (range: 1-31 years). All patients had medullary thyroid carcinoma (MTC). At the time of syndrome diagnosis, oral manifestations (bumpy lips, ganglioneuroma), ocular manifestations (corneal fibers, conjunctivitis sicca), intestinal dysfunctions, musculoskeletal manifestations, and pheochromocytoma were found in 86%, 90%, 74%, 79%, and 19% of the patients, respectively. At the time of follow-up examination, the symptoms were found at higher frequency. Severe intestinal manifestation was predominantly found in patients with prepubertal onset (< or = 12 years) of MTC (n = 4/10) compared with patients with late onset (> 12 years) of MTC (n = 0/11) (40% versus 0%; p = 0.019). Although biochemical cure was found only in four patients with early onset of MTC, the long-term prognosis for patients with early onset of MTC was poorer than for patients presenting with late onset of MTC (p = 0.005). During mean follow-up of 55.8 months (range: 3-161 months), seven patients (33%) died from MTC. In conclusion, whereas most typical MEN-2B symptoms were found to be age-related, severe intestinal manifestation was found to be predominantly expressed in patients with early onset of MTC. Furthermore, in patients with early onset of MTC who could not be biochemically cured, the long-term prognosis was found to be worse than that of non-cured patients with late onset of MTC, suggesting an additional pathological process in the younger subgroup reinforcing the very high transforming in vitro activity of the M918T RET mutation.

Critical size of residual adrenal tissue and recovery from impaired early postoperative adrenocortical function after subtotal bilateral adrenalectomy.

BACKGROUND: Subtotal bilateral adrenalectomy may preserve adrenocortical function. Little is known about the early postoperative function of the adrenal remnant. METHOD: In 10 patients with bilateral adrenal tumors (pheochromocytomas, adrenocortical nodular hyperplasia, and adrenal metastases), plasma adrenocorticotropic hormone (ACTH), serum cortisol, and maximal cortisol liberation were examined with an ACTH test after subtotal bilateral adrenalectomy, which left 15% to 30% of adrenal tissue in situ. RESULTS: In the early postoperative period, all patients had normal basal serum cortisol levels (mean, 415+/-208 nmol/L; normal morning range, 138-690 nmol/L) but pathologically increased plasma ACTH levels (mean, 55+/-42 pmol/mL; normal, <10.1 pmol/L). In 6 patients, a pathologic ACTH test result was observed. During follow-up (mean, 11.3+/-7.6 months), all patients were found to have a normal ACTH test result. None of the patients required steroid supplementation. However, in patients with both familial pheochromocytoma and impaired adrenocortical function during the early postoperative period, the maximal increase of serum cortisol after ACTH stimulation was significantly reduced (mean, 301+/-86.8 nmol/L) compared with control subjects (mean, 490+/-132.6 nmol/L; P=.019). CONCLUSION: After subtotal bilateral adrenalectomy left 15% to 30% of adrenal tissue in situ, functional recovery could be observed in all patients. However, subclinical impairment of the adrenocortical function with questionable clinical significance has to be considered in some of the patients. Especially during the early postoperative period, careful observation of the patients without exogenous steroid administration is required.

Malignant progression from C-cell hyperplasia to medullary thyroid carcinoma in 167 carriers of RET germline mutations.

BACKGROUND: Hereditary medullary thyroid carcinoma (MTC) is the most common and potentially life-shortening phenotypic manifestation of RET (rearranged during transfection) germline mutations. If a distinct time lag between the successive stages of malignant progression were identifiable, the information could be used to individualize prophylactic surgery. The study objective was to investigate the impact of RET genotype on disease progression from C-cell hyperplasia (CCH) to MTC. METHODS: An institutional series of 167 (67 index, 100 nonindex) consecutive carriers of RET gene point mutations in exons 10, 11, 13, 14, or 16 who underwent total thyroidectomy between November 1994 and November 2002. RESULTS: Regarding codons 618, 620, 634, 768, 790, and 804, patient age at diagnosis differed significantly depending on the type of pathology encountered (CCH, MTC without and with nodal metastasis). The variability in age, which may reflect the number of necessary somatic mutations, explained the pathological strata in 38% (codon 634) to 77% (codon 768) of patients. Conversely, 62% (codon 634) to 23% (codon 768) of variability in age at different pathological strata may have been determined by the RET genotype. CONCLUSIONS: The pace of malignant progression of the RET genotype should be taken into account when considering prophylactic thyroidectomy in RET gene carriers.

Enhancement of lymph node metastasis and distant metastasis of thyroid carcinoma.

BACKGROUND: The mechanisms of local and distant metastases are imperfectly understood. The goal of the current study was to add to the body of knowledge regarding local and distant metastases of thyroid malignancies. METHODS: The authors performed multivariate analysis of 573 patients who underwent surgery between November 1994 and May 2002 for follicular (FTC; n = 100), papillary (PTC; n = 236), or medullary thyroid carcinoma (MTC; n = 237) at a university hospital. RESULTS: In multivariate analysis, extrathyroidal extension consistently evolved as the key risk factor for both lymph node metastasis and distant metastasis. This correlation was most pronounced in MTC and least pronounced in FTC. The risk of lymph node metastasis also increased with reoperative status in patients with MTC and with primary tumor diameter in patients with MTC (tumor diameter > 10 mm) and patients with PTC (tumor diameter > 20 mm). In the PTC group, lymph node metastasis was more common among patients younger than age 45. In the MTC group, extrathyroidal growth and distant metastasis were associated exclusively with lymph node metastasis. Lymph node metastasis was the only secondary risk factor for distant metastasis. In the analysis of risk factors for distant metastasis in the FTC and PTC groups, no interaction was found between extrathyroidal growth and lymph node metastasis. This finding suggests that extrathyroidal growth and lymph node metastasis of FTC and PTC, and presumably also MTC, represent separate mechanisms and routes of distant metastasis. CONCLUSIONS: Screening for both local residual disease and distant metastases should be intensified in the high-risk population of patients whose primary tumors exhibit large diameters, extrathyroidal growth, or lymph node metastasis.

Functional results after endoscopic subtotal cortical-sparing adrenalectomy.

PURPOSE: We examined the required amount of residual adrenal tissue and whether an intact adrenal vein are necessary to achieve sufficient function after endoscopic subtotal adrenalectomy. METHOD: Endoscopic subtotal adrenalectomy was performed in 14 patients. Two patients underwent unilateral subtotal and contralateral total adrenalectomy and another two patients underwent unilateral subtotal adrenalectomy after contralateral total adrenalectomy several years earlier. We analyzed the postoperative serum levels of cortisol and adrenocorticotropic hormone (ACTH). Patients with bilateral tumors underwent an ACTH test. RESULTS: We had to cut the main adrenal vein in ten patients, and less than one third of the adrenal gland was left in situ in four patients. Subtotal adrenalectomy was performed unilaterally in two patients with bilateral tumors. One third of the adrenal gland was preserved in these patients, and also in the two patients with unilateral subtotal adrenalectomy after previous contralateral total adrenalectomy. The postoperative ACTH test confirmed satisfactory adrenocortical function. During the follow-up period of about 24 months no recurrent tumors have been found. CONCLUSION: Subtotal cortical-sparing adrenalectomy can be successfully performed laparoscopically. The venous drainage of the main adrenal vein does not seem to be crucial for sufficient adrenocortical function. We estimate that leaving about one third of the entire adrenal gland as remnant adrenal tissue will result in sufficient function.

RET proto-oncogene mutations affecting codon 790/791: A mild form of multiple endocrine neoplasia type 2A syndrome?

BACKGROUND: In patients with multiple endocrine neoplasia type 2A syndrome, prophylactic thyroidectomy is generally recommended at the age of 5 to 6 years. Whether this recommendation is justified for exon 13 mutations is unknown. METHODS: We analyzed the clinical data from 40 patients harboring RET codon 790/791 mutations (exon 13) who had been treated in 4 specialized centers. RESULTS: Mean age was 35.2 +/- 21.6 years (range, 5.1-69.0 years). Thirteen patients were index patients (mean age, 57.7 +/- 11.3 years), 27 patients were screening patients (mean age, 24.4 +/- 16.5 years). In the index group, pT-category was: T0, n = 2; T1, n = 6; T2, n = 2; T3, n = 1; and T4, n = 2. Lymph node metastases were found in 5 patients and distant metastases in 1 patient. Postoperatively, 69% of index patients were biochemically cured. In the screening group, pT-category was: T0, n = 19; T1, n = 7; and T2, n = 1. Lymph node metastases were found in 2 patients. Postoperatively, 93% of screening patients were biochemically cured. The youngest patient with medullary thyroid carcinoma was 13.8 years, the youngest patient with lymph node metastases was 46.4 years. CONCLUSIONS: Patients with RET codon 790/791 mutations seemed to have a less aggressive clinical course compared with patients with classic multiple endocrine neoplasia type 2A syndrome. Still, index patients had a lower biochemic cure rate in comparison with screening patients. Timely total thyroidectomy including lymph node dissection is warranted.

First experiences in intraoperative neurostimulation of the recurrent laryngeal nerve during thyroid surgery of children and adolescents.

BACKGROUND: Intraoperative neurostimulation of the recurrent laryngeal nerve may reduce nerve palsy during thyroid surgery and is well established in adults. No data regarding the value of neuromonitoring during thyroid surgery in children have been available. METHODS: In a retrospective study, the authors analyzed all children who underwent surgery in our department since 1995. Neurostimulation was performed as electromyography of the vocal muscle using an electrical stimulation electrode for identification of the recurrent nerve. RESULTS: The authors performed thyroid resections in 97 children (mean, 11.1 years), 75 because of thyroid carcinoma. The recurrent nerve was identified in each patient. The neuromonitoring was used in 53 patients. Postoperatively, one temporary nerve palsy was identified in this group (1.89%). In the group of 44 nonstimulated patients, 2 temporary (4.55%) and one permanent nerve dysfunctions (2.27%) occurred. In all stimulated patients, the results of intraoperative neurostimulation were identical with the postoperative function of the vocal cords. CONCLUSIONS: The intraoperative neurostimulation of the recurrent laryngeal nerve is a safe and reliable procedure in children and adolescents. It may reduce nerve damage during thyroid surgery. The neuromonitoring of the recurrent nerve is of high prediction for the postoperative function of the vocal cords.

Identification of the non-recurrent inferior laryngeal nerve using intraoperative neurostimulation.

INTRODUCTION: The non-recurrent inferior laryngeal nerve occurs at a frequency of about 0.5% and usually on the right side. The identification of a non-recurrent laryngeal nerve may be difficult. We describe a new method for its identification using intraoperative neurostimulation. METHODS: We examined nine patients with a non-recurrent inferior laryngeal nerve and five patients with a normal inferior laryngeal nerve anatomy who were operated on trans-sternally. Neurostimulation of the vagal nerve producing electromyographic signal in the intrinsic laryngeal musculature was performed at different points proximally and distally. RESULTS: : Electromyographic signals were found proximally but not distally of the separation of the inferior laryngeal nerve from the vagus in 14 patients. In nine patients with a non-recurrent inferior laryngeal nerve, we performed neurostimulation of the vagus opposite the lower and the upper thyroid poles. In all patients we found no electromyographic signals at the distal stimulation point. In contrast, proximal neurostimulation of the vagus opposite the upper thyroid pole produced positive electromyographic signals. CONCLUSION: Neurostimulation of the vagal nerve distally of the separation of the inferior laryngeal nerve did not produce electromyographic signals in the intrinsic laryngeal musculature, perhaps due to the different modalities in the vagal fascicles. Negative electromyographic signals following neurostimulation of the distal vagal nerve opposite the lower thyroid pole should lead to proximal neurostimulation of the vagus opposite the upper thyroid pole. Positive electromyographic signals proximally and negative electromyographic signals distally predict the occurrence of a non-recurrent inferior laryngeal nerve which allows its diagnosis before surgical dissection of the thyroid gland and may prevent nerve palsy.