Mortality associated with primary hyperparathyroidism.

561 patients with primary hyperparathyroidism were followed between 1961 and 1994. Relative survival was compared to that of the Australian population studied during the same time interval. Mortality was significantly greater in the hyperparathyroid population (P<0.001). Mortality was not greater in the patients with serum calcium levels >3.00 mmol/L compared to those with a serum calcium levels <3.00 mmol/L. 113 patients did not have parathyroid surgery. Their relative survival was not significantly different from those who had surgery but their mean serum calcium and parathyroid hormone (PTH) levels were significantly lower than those who had surgery. A re-analysis of the 453 patients followed between 1972 and 2011 was carried out and a 20-year survival analysis made of those diagnosed between 1972 and 1981 and those diagnosed between 1982 and 1991. The latter group had significantly worse relative mortality than the former group (P<0.001) but was significantly older at the time of diagnosis (56.94 ± 14.83 vs 52.01 ± 13.58, P<0.001). The serum calcium and serum PTH levels were not significantly different between these two groups.

Reoperative surgery for bilateral multinodular goitre in the era of total thyroidectomy.

BACKGROUND: Total thyroidectomy, rather than bilateral subtotal thyroidectomy, is now accepted as the preferred management for bilateral benign multinodular goitre (BMNG) in order to reduce the need for reoperative surgery. The aim of this study was to examine whether this approach has had an impact on presentation for bilateral reoperative thyroid surgery. METHODS: This was a retrospective cohort study. The study group comprised patients presenting with recurrent BMNG who underwent bilateral reoperative thyroid surgery following previous bilateral subtotal or partial thyroidectomy. They were compared with patients undergoing unilateral reoperative thyroid surgery following previous lobectomy, and those undergoing primary total thyroidectomy for BMNG. RESULTS: Between 1 January 1987 and 31 December 2009, 12 354 consecutive thyroid procedures were undertaken. Among those with BMNG, primary total thyroidectomy was undertaken in 3298 patients, unilateral reoperative thyroidectomy in 337 and bilateral reoperative thyroidectomy in 191. Presentations of patients with recurrent BMNG declined gradually over the study period following the change in policy from subtotal to total thyroidectomy; only five patients (representing less than 0.5 per cent of all thyroid surgery) underwent bilateral reoperative surgery for BMNG in the last year of the study. Four of these patients had their initial operation before 1987 and in another unit, whereas the remaining patient initially had surgery overseas. CONCLUSION: The introduction of a policy of initial total thyroidectomy for bilateral BMNG has essentially eliminated the need for bilateral reoperative surgery for recurrent goitre.

Surgical trends in the management of thyroid lymphoma.

AIMS: To determine the changing trends and current role of surgery for the management of thyroid lymphoma. METHODS: A retrospective review of 50 surgical patients with a final diagnosis of thyroid lymphoma over a 35-year period. RESULTS: All patients presented with an enlarging mass, with half having compressive symptoms on presentation. Two-thirds of patients had co-existent histological features of Hashimoto's thyroiditis. Surgery for patients with thyroid lymphoma peaked in the late 1970s (0.79% of all thyroid operations performed) followed by a significant decline in the 1980s with a current frequency of only 0.16% (p=0.009). A larger number of thyroid resections intended as a curative procedure was performed during the first half of this series compared to the latter half (p=0.05). There was no difference in disease-free survival between patients treated by thyroid resection when compared with an open biopsy (p=0.4875). CONCLUSION: The surgical management of thyroid lymphoma has changed with time. Currently a larger proportion of patients are undergoing surgery in order to achieve a histological diagnosis rather than with therapeutic intent, however, an important role for surgery still exists in the management of a patient with severe airways obstruction.

Minimally invasive parathyroidectomy using the lateral focused mini-incision technique without intraoperative parathyroid hormone monitoring.

BACKGROUND: Minimally invasive parathyroidectomy (MIP) involves scan-directed removal of a single adenoma through a 2.0-cm mini-incision without intraoperative monitoring. The aim of this study was to analyse the outcomes of MIP using such a simplified technique. METHODS: The study group comprised 500 consecutive patients undergoing MIP via a lateral mini-incision from August 2000 to September 2005. Levels of parathyroid hormone (PTH) were measured after operation solely to aid informed discharge. RESULTS: Some 97.4 per cent of patients were initially cured by MIP. Eight patients remained hypercalcaemic and a further five were normocalcaemic on the day after surgery but became hypercalcaemic again within 3 months of the procedure. Eleven of these patients were cured with subsequent re-exploration. Analysis of postoperative PTH data indicated that, at best, the use of intraoperative PTH measurement during surgery would have increased the cure rate by only a further 1 per cent. Three (0.6 per cent) of 500 patients had permanent recurrent laryngeal nerve palsy after MIP. CONCLUSION: MIP performed by the lateral focused mini-incision technique, without the use of intraoperative PTH monitoring, is a safe and effective procedure that results in outcomes equal to those of bilateral neck exploration.

Equivalency of reaction times for simple and primed tasks.

Both simple and choice reaction-time tasks have been used to examine the processes involved in response preparation. With a response priming task, complete information prior to the presentation of the imperative stimulus is given as to which response among several will be required. It is assumed that with the priming procedure, the advanced information allows for the complete preparation of the response to be made prior to the presentation of the imperative stimulus [Klapp, S. T. (1996). Reaction time analysis of central motor control. In H. N. Zelaznik (Ed.), Advances in motor learning and control (pp. 13-36). Champaign, IL: Human Kinetics]. This study used two experiments to test the underlying assumption that the processes occurring within the reaction time interval are equivalent for simple and primed tasks, and to determine if the validity of the prime influences performance. In both experiments, participants completed three reaction-time tasks: simple, primed (100%), and choice. The second experiment added a fourth task in which the prime was valid only 80% of the time. In both experiments, the reaction times were significantly slower for the choice task than for either the simple or 100%-primed tasks. Most important, the simple and primed (100%) reaction times were not significantly different. For the second experiment, the reaction times were not significantly different for the choice and 80%-valid prime tasks. The results of these experiments demonstrate that equivalent response preparation processes occur for simple and primed tasks, but that the validity of the prime does influence the response preparation processes for the primed task. Thus, equivalency is not achieved when invalid primes are used.

Lymphadenectomy for papillary thyroid cancer: changes in practice over four decades.

AIMS: Lymphadenectomy in the management of papillary thyroid cancer (PTC) has evolved. The aim of this study was to examine the changing role of neck dissection as reflected in the practice of a large thyroid unit over four decades. METHODS: A retrospective cohort study of patients that underwent primary thyroid surgery for papillary cancer in a single unit in the period 1958-2002. Nine 5-year periods were considered and the data relevant to the treatment of the regional lymph nodes reviewed. RESULTS: Nine hundred patients with PTC underwent surgery between 1958 and 2002 of whom 32.7% underwent lymph node dissection (LND). The use of lymphadenectomy increased from 21.4% in 1958-1962 to 48.1% in 1998-2002 of which 84% underwent a selective lymph node dissection (SLND)-a dissection where the LND is determined by the extent of the disease encountered. The mean number of nodes removed during SLND was 12.6 (range 1-56) of which a mean of 3.1 (24.8%) (0-19) were involved by the disease. Cervical levels 6 and level 4 were those most frequently dissected. There was no statistically significant difference in the complication rates in patients undergoing neck dissection and those not. CONCLUSION: The four decade experience reflects a move away from modified radical neck dissection and cherry picking towards SLND. Growing evidence suggests that lymphadenopathy in adult PTC is an adverse prognostic factor. SLND, a lymphadenectomy tailored to the extent of the disease process, is the coherent treatment for PTC since it serves the dual purpose of staging as well as control of local disease. This can be achieved with little morbidity when performed in a specialist centre.

Studies in motor behavior: 75 years of research in motor development, learning, and control.

Research focused on human motor development, learning, and control has been a prominent feature in the Research Quarterly for Exercise and Sport (RQES) since it was first published in 1930. The purpose of this article is to provide an overview of the papers in the RQES that demonstrate the journal's contributions to the study of motor development, learning, and control. The landmark study by Henry and Rogers (1960), the C. H. McCloy lectures, and theoretical and review papers in motor behavior are highlighted. The RQES has served as a significant outlet for research in development, learning, and control throughout its 75-year history. The convergence of the theories, research methods and analytical tools lead to the proposition that these three areas have evolved into afield best described as motor behavior.

Impact of timing on completion thyroidectomy for thyroid cancer.

BACKGROUND: It has been stated that completion thyroidectomy for thyroid malignancy should be performed either within 10 days of the primary operation or after 3 months, to reduce the incidence of complications. The aim of this study was to review the impact of timing on the rate of complications following completion thyroidectomy. METHODS: Data were obtained retrospectively from the Endocrine Surgery Thyroid Data Base, to which the records of all patients have been entered since 1957. The patients who had the last 100 consecutive completion thyroidectomies for thyroid cancer comprised the study group. RESULTS: Sixty-three patients had the second operation performed within 10 days or more than 90 days after the initial operation (group 1). Thirty-seven patients had reoperation between 10 and 90 days after the first procedure (group 2). One patient (2 per cent) in group 1 and one patient (3 per cent) in group 2 suffered a permanent complication (P not significant). CONCLUSION: There was no definite impact of the timing of surgery on the rate of complications after completion thyroidectomy.

Influence of practice on response-selection and response-implementation processes involved in the response-interference effect.

In a choice reaction-time task, the response-interference effect is an increase in reaction times when the two possible responses are from the same hand compared to when the two possible responses are from different hands [Psychonomic Science 2 (1965) 55-56; Human Motor Control, Academic Press, San Diego, CA, 1991]. Although the influence of practice on other reaction-time effects (i.e., the complexity effect and precuing) has been examined, research evaluating the influence of practice on the response-interference effect is limited. Therefore, two experiments were conducted to determine the influence of practice on the response-interference effect. In Experiment 1, a bilateral transfer task was used to assess the influence of practice on the response-selection processes associated with the response-interference effect. The practice results indicated decreased reaction times, but did not influence the response-interference effect. In Experiment 2, a priming task was used to assess the influence of practice on response-implementation processes associated with the response-interference effect. The reaction time results indicated a change in the response-interference effect. The results of these two experiments suggest that with only two fingers on response keys, practice alters the mechanical constraints affecting the response-implementation processes and thereby decreases the response-interference effect.

Intraoperative quick parathyroid hormone versus same-day parathyroid hormone testing for minimally invasive parathyroidectomy: a cost-effectiveness study.

BACKGROUND: Intraoperative quick parathyroid hormone (QPTH) measurement is claimed to eliminate failures during minimally invasive parathyroidectomy. The cost-effectiveness of QPTH (ie, true cost of avoiding a failed operation) needs careful evaluation. METHODS: In 92 consecutive patients who underwent minimally invasive parathyroidectomy via a small lateral incision, QPTH was estimated preoperatively and at 5, 10, and 15 minutes postparathyroidectomy. QPTH results were subsequently compared with the procedure outcome. Cost-effectiveness analysis was performed for 3 subsequent theoretical management strategies: QPTH not performed, QPTH results available intraoperatively, and parathyroid hormone and serum calcium levels measured routinely with results made available the same day. RESULTS: With criteria for cure being a decrease in the QPTH measurement to less than 50% of preoperative levels and to within normal range, QPTH predictions were true positive in 78 patients; false-negative in 7; false-positive in 1; and true negative in 2. The true cost of using QPTH measurement to avoid a failed operation was 19,801.19 US dollars, with 7 patients undergoing unnecessary conversion. Routine same-day parathyroid hormone and calcium measurements significantly reduced this to 624.73 dollars. Sensitivity analysis with varying cost assumptions demonstrated cost-effectiveness analysis to be robust. CONCLUSIONS: The fact that 97% of patients will be cured regardless of QPTH testing combined with its false-negative rates significantly reduces the cost-effectiveness of the test when compared with same-day parathyroid hormone testing.

Incidence and importance of the tubercle of Zuckerkandl in thyroid surgery.

OBJECTIVE: To define the incidence of a distinct tubercle of Zuckerkandl (TZ) and confirm its anatomical relationships with the recurrent laryngeal nerve and the superior parathyroid gland. DESIGN: Two prospective series. SETTING: University teaching hospital, Australia. SUBJECTS: 200 patients who required thyroidectomy. INTERVENTIONS: Anatomical and clinical observations in two series of patients (n = 100 in each). The first defined the incidence of a TZ and preoperative symptoms; the second delineated the relationship of the TZ to the recurrent laryngeal nerve and the superior parathyroid gland. MAIN OUTCOME MEASURES: Anatomical relationships. RESULTS: A TZ was identified in 63% of patients and was > 1 cm in 45%. In 93% of patients with an enlarged TZ, the recurrent laryngeal nerve lay medial to it and the nerve was found lateral to the TZ in 7% of cases. The superior parathyroid gland was usually cranial to the TZ and posterior to the recurrent laryngeal nerve. The size and position of the TZ did not correlate clearly with symptoms. CONCLUSIONS: The TZ is a distinct feature of the thyroid gland that can be recognised during most thyroidectomies. The size and the position of the TZ have no constant relationship to preoperative symptoms. An understanding of the consistent anatomical relationship between the TZ and recurrent laryngeal nerve and superior parathyroid gland is crucial for safe thyroidectomy.

Routine parathyroid autotransplantation during total thyroidectomy: the influence of technique.

OBJECTIVE: To find out whether injecting a suspension of finely minced parathyroid tissue into the muscle bed had any adverse outcomes as it is simpler and potentially safer than implanting parathyroid tissue into muscle pockets. DESIGN: Prospective, randomised, controlled clinical trial. SETTING: University hospital, Australia. PATIENTS: 50 patients who were to have total thyroidectomy and routine parathyroid autotransplantation. INTERVENTIONS: Patients were randomised to either the injection technique or the implantation technique. MAIN OUTCOME MEASURES: Clinical assessment; corrected serum calcium and intact parathyroid hormone concentrations (PTH) measured immediately before, and at 1 day, 2 weeks, and 3 months after operation. RESULTS: Calcium was reduced significantly in both groups immediately after thyroidectomy. Although mean PTH concentrations decreased immediately after thyroidectomy and parathyroid autotransplantation in both groups, these changes were significant only in the implantation group. By 2 weeks and again by 3 months, calcium and intact parathyroid hormone concentrations had returned to baseline in both groups. At 3 months, 2 patients in each group still required some form of calcium supplement. At 6 months, no patients in the injection group required supplement. CONCLUSIONS: Injection of a suspension of parathyroid tissue is a simple, safe, and rapid technique for parathyroid autotransplantation during total thyroidectomy and is not associated with any more adverse outcome than is the standard technique.

Minimally invasive parathyroidectomy: 50 consecutive cases.

OBJECTIVE: To determine the effectiveness and outcomes of minimally invasive parathyroidectomy. DESIGN: Prospective, non-randomised, non-blinded trial. SETTING: Affiliated university teaching hospitals of the Northern Clinical School, University of Sydney, New South Wales, May 1998 to October 1999. PATIENTS: 50 consecutive patients who underwent minimally invasive parathyroidectomy for primary hyperparathyroidism, and 150 consecutive patients undergoing open parathyroidectomy over the same period. RESULTS: Minimally invasive parathyroidectomy was successfully completed and resulted in cure (normocalcaemia) in 42 of 50 patients (84%). Seven patients (14%) required conversion to an open procedure, all of which also resulted in normocalcaemia, giving an overall cure rate of 98%. One patient had persistent hyperparathyroidism after minimally invasive parathyroidectomy which was cured at subsequent open reoperation. Three patients had a temporary recurrent laryngeal nerve palsy. Open parathyroidectomy was successful in 147 of 150 patients (98%) at initial operation; one patient had a temporary recurrent laryngeal nerve palsy. Intraoperative measurement of parathyroid hormone levels by a quick technique in 23 of the patients (13 having minimally invasive and 10 open procedures) correctly identified the presence of multiple-gland disease. CONCLUSION: Minimally invasive parathyroidectomy is a feasible procedure, although there are concerns about the complication rate.

Complications of thyroid surgery: how to avoid them, how to manage them, and observations on their possible effect on the whole patient.

Surgery of the thyroid takes place in an area of complicated anatomy and in which a number of vital physiologic functions and special senses are controlled. Thyroidectomy rarely is associated with mortality; but unless the surgeon performing it is well trained in operative surgery and is knowledgeable of the gland and its function, pathology, and anatomy, excellent results cannot be achieved. Failure to observe cardinal surgical principles may result in legal difficulties, which can be avoided. It is well to observe the principles and avoid problems. We address this issue herein.

Minimally invasive surgery for primary hyperparathyroidism: systematic review.

HYPOTHESIS: Use of minimally invasive parathyroidectomy techniques, either unilateral or endoscopic, will result in the same or improved safety and efficacy outcomes as those of the bilateral open neck exploration technique in patients with primary hyperparathyroidism. DATA SOURCES: Studies on minimally invasive parathyroid surgery were identified using MEDLINE (January 1984 to August 1998), EMBASE (January 1974 to August 1998), and Current Contents (week 1 of 1993 to week 34 of 1998). The search terms were as follows: ((endoscop* or (minimal* and invasive) or unilateral) and parathyroid). The Cochrane Library was searched from issue 1 of 1966 to issue 3 of 1998, using the search terms "parathyroidectomy or parathyroid resection." STUDY SELECTION: Human studies of patients with primary hyperparathyroidism using unilateral or endoscopic exploration were included. Animal studies describing minimally invasive technique development were also included. A surgeon (R.F.P.) and researcher (W.J.B.) independently assessed the retrieved articles for their inclusion in the review. DATA EXTRACTION: Studies directly comparing the unilateral method with bilateral open neck exploration were used to analyze outcomes. DATA SYNTHESIS: Analysis of data using odds ratios and 95% confidence intervals indicated a tendency to favor the unilateral technique. However, these individual studies generally had large confidence intervals; therefore, preference to the unilateral procedure cannot be espoused with certainty. There is also a selection bias due to the strict enrollment criteria for unilateral surgery. CONCLUSIONS: The proposed role of minimally invasive parathyroid surgery is for patients with primary hyperparathyroidism who have unilateral parathyroid pathological features. To assess the safety and efficacy of minimally invasive techniques, it is suggested that their introduction be monitored as part of a trial in Australia, from which data should be accrued to a register.

Minimally invasive surgery for primary hyperparathyroidism: a systematic review.

BACKGROUND: The aim of the present paper was to systematically review the literature regarding the safety and efficacy of minimally invasive parathyroidectomy techniques in patients with primary hyperparathyroidism. Studies using unilateral or endoscopic exploration following imaging were compared with bilateral open neck exploration. METHODS: Studies on minimally invasive parathyroid surgery were identified using MEDLINE (1984 to August 1998), EMBASE (1974 to August 1998) and Current Contents (1993 to week 34, 1998). The search terms were ((endoscop* or (minimal* and invasive) or unilateral) and parathyroid). The Cochrane Library was searched from 1966 to issue 3 1998, using the search terms 'parathyroidectomy or parathyroid resection'. Human studies of patients with primary hyperparathyroidism using unilateral or endoscopic exploration were included. Animal studies describing minimally invasive technique development were also included. A surgeon and researcher independently assessed the retrieved articles for their inclusion in the review. Studies directly comparing the unilateral method with bilateral open neck exploration were used to analyse outcomes. RESULTS: Analysis of data using odds ratios and 95% confidence intervals (CI) indicated a tendency to favour the unilateral technique. These individual studies generally had large CI, however; therefore preference to the unilateral procedure cannot be espoused with certainty. There is also a selection bias due to the strict enrollment criteria for unilateral surgery. CONCLUSIONS: The proposed role of minimally invasive parathyroid surgery is for patients with primary hyperparathyroidism who have unilateral parathyroid pathology. To assess the safety and efficacy of minimally invasive techniques it is suggested that their introduction be monitored as part of a trial in Australia, from which data should be accrued to a register.