A prospective study of heart rate variability in endocrine surgery: surgical training increases consultant's mental strain.

BACKGROUND: The aim of this study was to determine whether instructing surgical trainees in technically demanding procedures causes alterations in heart rate variability (HRV) and mental strain in supervising surgeons. METHODS: A prospective study of HRV in two consultant surgeons and three endocrine surgical fellows undertaking 50 total thyroidectomy procedures was performed. Fellows and consultant surgeons performed 50 lobectomies as primary operator and 50 as assistants in a cross-over design. HRV was measured during dissection around the recurrent laryngeal nerve. The overall heart rate, time, and frequency domain parameters of HRV, specifically the low frequency/high frequency (LF/HF) ratio, which was used as a measure of cardiac and mental stress, were correlated with the surgical role, particularly teaching surgical fellows at critical points. RESULTS: HRV data were collected between October 2009 and March 2010. There was no statistically significant difference in the mean heart rate for either group of participants regardless of role. Energy expenditure was greater for fellows when operating (p = 0.03). Fellows demonstrated a higher LF/HF ratio when acting as the primary operator (p = 0.02). All time domain parameters of HRV increased when attending surgeons were operating, denoting more cardiac relaxation. Similarly, the LF/HF ratio was significantly greater for attending surgeons when teaching (p = 0.05), suggesting an increase in mental strain. CONCLUSIONS: The teaching of complex but common endocrine surgical procedures is associated with a measurable increase in mental strain of consultant surgeons, as determined by HRV. Fellows demonstrated increased levels of stress when acting as primary operators.

Is focused minimally invasive parathyroidectomy appropriate for patients with familial primary hyperparathyroidism?

BACKGROUND: The aim of this study was to determine whether a focused minimally invasive parathyroidectomy (MIP) for patients with primary hyperparathyroidism and concordant pre-operative localization studies is appropriate for patients with a family history of the disease. Familial hyperparathyroidism may be seen as a chronic disease in which recurrence is inevitable. Patients frequently undergo subtotal or total parathyroidectomy for perceived 4-gland parathyroid hyperplasia in an attempt to reduce this risk. Controversy remains regarding whether a MIP is appropriate in this setting. METHODS: Patients undergoing an MIP were identified from prospectively maintained databases. Chart review confirmed the presence of a family history of hyperparathyroidism in a direct relative. Patients with and without a family history were compared regarding overall complications, recurrence, and cure rates. RESULTS: A total of 1,652 patients underwent a MIP. Of these, 34 patients had a positive family history. There was no statistically significant difference in age, gender, preoperative biochemistry, gland weight, or complication rates between the groups. The cure rate at 6 months from a single operation was equivalent between the 2 groups (97 vs. 98%). With a median of 39 months follow-up, the recurrence rate was higher in those with a family history compared with those without (8.8 vs 1.1%; P=0.002). Reoperation was successful in the small population of familial patients who did present with recurrent hyperparathyroidism. CONCLUSIONS: The vast majority of patients who underwent a MIP were surgically cured. Although recurrence rates remain higher in the familial hyperparathyroidism group, these data suggest that this alone should not be a contraindication to MIP.

Durability of focused minimally invasive parathyroidectomy in young patients with sporadic primary hyperparathyroidism.

BACKGROUND: Historically, multigland hyperplasia was believed to be the predominant cause of primary hyperparathyroidism (PHPT) in young patients, and hence a relative contraindication for minimally invasive parathyroidectomy. Recent studies, however, demonstrate that the most common aetiology across all age groups is a solitary functioning adenoma. The aim of this study was to compare long-term outcomes in young patients (≤ 45 years), especially those under 30 years of age, with their older counterparts (> 45 years) following focused minimally invasive parathyroidectomy (FMIP). MATERIALS AND METHODS: Patients ≤ 45 years who underwent FMIP between January 1999 and December 2007 were identified from an endocrine surgery database and compared with a matched control group of patients > 45 years old also undergoing FMIP within that time period. The patients' most recent calcium levels (≥ 6 months postoperatively) were examined to establish recurrence rates. Recurrence was defined as an elevation of serum calcium more than 6 months after surgery following initial postsurgical normocalcemia. RESULTS: A total of 117 patients ≤ 45 years and 160 patients > 45 years who underwent FMIP were examined. Follow-up calcium levels were available for 72% of patients. The median length of follow-up was 46 months. No recurrences were identified in both the younger and older cohort of patients; therefore, no statistically significant difference in rates of recurrence could be determined between age groups. CONCLUSION: Recurrence of PHPT following FMIP is rare with no evidence of a higher incidence in younger patients. FMIP can be safely offered to young patients as a long-term durable treatment option.

Cytotoxic 1,4-bis(2-oxo-1-cycloalkylmethylene)benzenes and related compounds.

A series of 1,4-bis(2-oxo-1-cycloalkylmethylene)benzenes 2a-c and 4 and a related acyclic analogue 6a were synthesised and converted to the corresponding Mannich bases 3a-c, 5 and 6b. Evaluation of these compounds against murine P388 and L1210 cells as well as human Molt 4/C8 and CEM T-lymphocytes revealed that the Mannich bases were more cytotoxic than the corresponding unsaturated ketones. 1,4-bis(3-Dimethylaminomethyl-2-oxo-1-cyclohexylmethylene)benzene dihydrochloride (3a) had lower IC(50) values than melphalan against the four cell lines and was 15 times more potent than this drug when examined against a panel of human tumours.