Prospective validation study of Cernea classification for predicting EMG alterations of the external branch of the superior laryngeal nerve

Purposes

Cernea classification is applied to describe the external branch of the superior laryngeal nerve (EBSLN). Using intraoperative neural monitoring we evaluated whether or not this classification is useful for predicting which EBSLN subtype has an increased risk of injury.

Methods

An analysis of 400 EBSLN. The identification of EBSLN was achieved with both cricothyroid muscle twitch and the glottis evoked electromyography response. We defined S1 initial EBSLN stimulation at identification and S2 final nerve stimulation achieved in the most cranial aspect of the nerve exposed above the area of surgical dissection after superior artery ligation.

Results

The mean S1 amplitude acquired was 259+/67 (180–421), 321 +/79 (192–391), 371 +/38 (200–551) μV, respectively, for type 1, 2A, 2B (p = 0.08). The S1 and S2 amplitudes were similar in type 1 (p = 0.3). The S1 and S2 determinations changed significantly in type 2A and 2B (p = 0.04 and 0.03). EBSLN which demonstrated a >25 % decreased amplitude in S2 increased significantly from Type 1 (4.9 %) to Type 2A (11.2 %) and 2B (18 %) (p = 0.01). None of type 1, 2.8 % type 2A and 3 % type 2B showed a loss of EBSLN conductivity. The latency determinations did not vary significantly for any parameter compared.

Conclusions

The Cernea classification was, therefore, found to predict the risk of EBSLN stress. We identified amplitude differences between S1 and S2 determinations in type 2A and 2B, thus confirming that surgical dissection in these subtypes is, therefore, extremely difficult to perform.

     

Surgical strategy for primary hyperparathyreoidism with thyroid hemiagenesis

Background

Thyroid hemiagenesis is a rare congenital anomaly, and still more rarely associated with primary hyperparathyroidism (pHPT). Due to the embryologic pathways of the thyroid and parathyroid glands, it remains unclear whether or not thyroid hemiagenesis may be linked to ipsilateral parathyroid agenesis, and consequently, surgical strategy for thyroid hemiagenesis associated pHPT (THAP) does not only depend on preoperative localization but also on the thyroid anomaly.

Methods

Including the present case report, a total of nine cases with THAP retrieved from the literature were reviewed. Seven of nine cases had thyroid hemiagenesis on the left side, three out of nine showed a parathyroid adenoma on the contralateral side to the thyroid hemiagenesis.

Conclusions

Based on these cases, it can be concluded that the embryologic pathways of the thyroid and parathyroid glands are different, and in cases of THAP, parathyroid exploration should follow standard recommendations for pHPT surgery.     

Solid pseudopapillary tumor of the pancreas. Consideration of two cases

Solid pseudopapillary tumor of the pancreas (SPTP) is a rare primary pancreatic neoplasm of unknown etiology, occurring most commonly in young women. It is a neoplasm with a low malignancy and a good prognosis after surgical removal. For this reason it is important to distinguish this tumor from other pancreatic tumors and, in particular, from the more frequent carcinomas. Two cases of SPTP are presented with a review of the literature. The first case was of a 67-year-old woman with a 2 cm mass in the head of the pancreas and the second was of a 44-year-old woman with a 6 cm mass in the head of the pancreas. In both cases the pancreatic lesions were shown by ultrasonography and a computed tomography scan. The biopsy performed under ultrasound guidance did not allow a certain pre-operative diagnosis and, for this reason, the two patients underwent a pancreaticoduodenectomy as in cancer of the pancreas. Only histological examination permitted a definite diagnosis of SPTP. In the second case a histopathological pattern indicated a low malignant potential, while in the first case the neoplasm showed an infiltrative growth into the surrounding pancreatic parenchyma, suggestive of high malignant potential. Some authors consider this latter neoplasm as a subgroup of SPTP which distinguishes itself through its higher malignant potential. Our experience suggests that aggressive surgery must be chosen in all cases where a pre-operative certain diagnosis is unavailable.     

Screening for lung cancer

The large clinical studies of lung cancer screening carried out more than 20 years ago were interpreted as evidence against screening. Those studies have been recently reassessed in the light of methodologic flaws in the randomization of subjects at risk for lung cancer. There is no evidence to support the former conclusion that screening is ineffective and the consequent official recommendation not to screen for lung cancer. The hypothesis of overdiagnosis of lung cancers diagnosed by screening is false. Clinical evidence supports the concept that the current dogma against screening for lung cancer is untrue. Indeed, the 5-year survival rate of patients with NSCLC detected in stage I and radically resected ranges from 60% to 80%. This rate is in sharp contrast to the 10% survival rate of stage I NSCLC not resected. About 90% of lung cancer cases are detected among smokers and former smokers; these well-known at-risk subjects should be offered a screening test with the goal of detecting the disease when it is in stage I. It is expected that the techniques for early detection of lung cancer will be refined and become more sensitive in the near future, so that it will be possible to detect an increasingly large proportion of lung cancers when they are truly in stage I (i.e., nonmetastatic) and curable by radical surgical resection. Low-dose helical CT scan is currently believed to represent a very useful technique for screening for lung cancer, with a higher sensitivity than chest radiograph screening. Chest radiography for lung cancer screening, however, is cheaper and ubiquitously available, and it should still be recommended if CT scan is locally unavailable. As underscored in a recent commentary in The Lancet, the existing public health policy discouraging the screening for lung cancer is in urgent need of reconsideration.