Biomedical subjects

Leigh W Delbridge

Publications and source records attributed to Leigh W Delbridge.

At least 19 recordsLinked to original sources

PubMed2007

Minimally invasive parathyroidectomy using the lateral focused miniincision approach: Is there a learning curve for surgeons experienced in the open procedure?

BACKGROUND: Minimally invasive parathyroidectomy (MIP) has gained acceptance as the standard of care for management of primary hyperparathyroidism in which a single adenoma can be localized. The aim of this study was to determine if there is a learning curve for MIP using the lateral focused miniincision approach performed by surgeons experienced in open parathyroidectomy. STUDY DESIGN: This is a retrospective case series comprising all parathyroid operations undertaken by three surgeons in the University of Sydney Endocrine Surgical Unit from 2003 to 2005. Outcomes of the experienced surgeon were compared with those of the two surgeons commencing practice. RESULTS: There were 699 parathyroidectomies performed in the Unit during the 36-month period (experienced surgeons: 438 versus commencing physicians: 261). Of the parathyroidectomies performed, 57% done by experienced surgeons were minimally invasive compared with 38% of those performed by surgeons commencing practice (p < 0.001). There were no differences in the number of complications (p = 0.21), conversions to open exploration (p = 0.6), and cure rates (p = 0.9) in the MIP patients in both groups. The initial (first 131 patients) and subsequent (next 130 patients) parathyroidectomy experiences of surgeons commencing practice were examined. In the initial experiences, 28% of the cases were minimally invasive compared with 48% in the subsequent experiences (p < 0.001). There were no differences in the number of complications (p = 0.3), conversions to open exploration (p = 0.9), and cure rates (p = 0.9). CONCLUSIONS: For surgeons experienced in open parathyroidectomy, there is no technical learning curve using the lateral focused miniincision technique for MIP. There is, however, a learning curve for patient selection.

Clinical Competence↗

PubMed2006

Completion thyroidectomy for malignancy after initial minimal access thyroid surgery.

BACKGROUND: Minimal access thyroid surgery (MATS), carried out through a lateral 2.5-cm incision, provides excellent clinical and cosmetic outcomes when carried out for small (<3 cm), single nodules. However, if the final pathology shows thyroid malignancy and a completion thyroidectomy is required, the small lateral incision requires conversion to a standard collar incision and the second operation must be carried out in the presence of previous lateral dissection. The aim of this study is to determine if there is any demonstrable disadvantage to completion thyroidectomy for malignancy after MATS when compared with the same procedure after conventional hemithyroidectomy. METHODS: This retrospective cohort study examined all patients undergoing completion thyroidectomy for malignancy in the University of Sydney Endocrine Surgical Unit from January 2002 to January 2005. Outcome measures were complication rates, final scar length and patient's self-assessment of scar appearance. RESULTS: A total of 106 patients underwent MATS during the study period, 11 of whom required completion thyroidectomy for malignancy. During the same period, 42 patients required completion thyroidectomy for malignancy after previous conventional hemithyroidectomy. There was no difference in complication rates between the two groups. The two complications in the study consisted of one case of flap oedema (control) and one case of keloid scar (MATS). Mean final incision length, scar appearance and patient's satisfaction with scar did not differ between the two groups. CONCLUSION: There is no demonstrable disadvantage when completion thyroidectomy for malignancy is required after MATS.

Adult↗

PubMed2006

New era: prophylactic surgery for patients with multiple endocrine neoplasia-2a.

BACKGROUND: The surgical management of patients with multiple endocrine neoplasia-2A (MEN-2A) continues to evolve with specific genotype-phenotype correlations allowing for a more tailored approach. In this study, we report the surgical management of one of the largest MEN-2A families with a rearranged during transfection (RET) codon 804 mutation. METHOD: This is a cohort study comprising all at-risk kindred within a single known MEN-2A family. Prophylactic total thyroidectomy with lymph node dissection was recommended to all mutation carriers aged 5 years and older. RESULTS: There were a total of 48 at-risk individuals in the MEN-2A kindred, with 22 patients undergoing thyroidectomy after appropriate preoperative evaluation. A total of 9 patients had medullary thyroid cancer including 5 with a normal preoperative calcitonin level. A total of 11 patients had C-cell hyperplasia and 7 showed histological evidence of parathyroid disease. Only the index case had a phaeochromocytoma. CONCLUSIONS: Genetic testing for germline mutations in the RET proto-oncogene has allowed precise identification of affected RET carriers and provided the opportunity for prophylactic or 'preclinical' surgery to treat and in fact to prevent medullary thyroid cancer. This concept of prophylactic surgery based on a genetic test is likely to be applied more widely as the tools of molecular biology advance.

Adolescent↗

PubMed2006

New surgical consultants: is there a learning curve?

The purpose of this study was to determine whether newly established surgeons who have completed dedicated post-fellowship training are able to achieve surgical outcomes comparable to their more experienced peers. A cross-sectional study of consecutive patients undergoing total thyroidectomy (TT) or completion thyroidectomy was carried out. Outcomes measured included unplanned return to the operating theatre, postoperative infection, permanent recurrent laryngeal nerve (RLN) injury and permanent hypoparathyroidism. Outcomes were categorized according to whether surgery was carried out by an established surgeon (ES) or a newly appointed surgeon (NAS). Eight hundred and nine TT and completion thyroidectomy procedures were carried out in the period January 2002 to December 2004. Of these, 515 (64%) were carried out by ES and 294 (36%) were carried out by NAS. The overall rate of permanent hypoparathyroidism and RLN injury was 1.4% (12/809) and 0.6% (5/809), respectively. The rate of permanent hypoparathyroidism was not significantly different between the two categories of surgeon (ES 1.35% vs NAS 1.7%; P = 0.7). The incidence of permanent RLN injury was not different between the two groups (ES 0.8% vs NAS 0.3%; P = 0.4). For NAS, the rate of permanent RLN injury for the first two years of independent practice did not differ significantly from 3 to 4 years of practice (0/123 vs 1/171; P = 0.4). Indications for surgery between the two groups were similar, with ES carrying out TT for benign goitre in 42% and cancer in 28%, and NAS 44 and 32%, respectively. Surgical outcomes for the newly established endocrine surgeon following subspecialty training are equivalent to those achieved by more experienced surgeons.

Adult↗

PubMed2005

Phaeochromocytoma: current concepts.

The discovery of novel mutations in genes encoding succinate dehydrogenase subunits has revealed that familial phaeochromocytomas are much more common than previously thought. Genetic screening should be offered to patients with apparently sporadic phaeochromocytomas and their first-degree relatives. An increasing proportion of phaeochromocytomas present preclinically on genetic testing or as "incidentalomas" on abdominal imaging, rather than with classic symptoms and signs. Clinical suspicion should prompt measurement of plasma levels of free metanephrine or 24-hour urinary catecholamine and metanephrine levels, followed, if positive, by tumour localisation studies. With appropriate perioperative care, surgical management of phaeochromocytomas is safe and effective. Most tumours can be removed laparoscopically.

Adrenal Gland Neoplasms↗

PubMed2005

Potential pitfalls in the diagnosis of phaeochromocytoma.

Six patients being evaluated for phaeochromocytoma had misleading investigative findings: all initially had raised urinary catecholamine levels, and five had adrenal masses on imaging studies. Adrenalectomy in these five patients revealed only one pathologically confirmed phaeochromocytoma. Tricyclic antidepressant use produced misleading elevations in urinary catecholamine levels in three patients. 24-hour urine studies should be performed at least twice, after eliminating confounding factors (stressors, medications).

Adrenal Gland Neoplasms↗

PubMed2005

Safety and feasibility of thyroid lobectomy via a lateral 2.5-cm incision with a cohort comparison of the first 50 cases: evolution of a surgical approach.

BACKGROUND AND AIMS: Over 500 minimal-access parathyroidectomies (MIPs) have been performed in our unit, and, from these, a technique for thyroid resection has evolved. We present a report on the evolution of minimal-access thyroid surgery (MATS) and compare the results with those from a cohort of patients operated on prior to the use of MATS. METHODS: We reviewed the evolution towards the MATS technique. The results of the MATS procedures were compared with those from an equal number of consecutive patients undergoing conventional lobectomy prior to the use of MATS. RESULTS: Fifty patients (mean age 45.6 years) underwent MATS between March 2002 and May 2004. The mean nodule diameter was 18.5 mm. In the MATS group there was one recurrent laryngeal nerve (RLN) injury, two temporary RLN neuropraxias, which recovered, and one haematoma. The control group (mean age 47.9 years) had a mean nodule size of 22 mm. In the controls there was one temporary RLN neuropraxia, which recovered, and two haematomas-P>0.05 (Fisher's exact test) for all the complications. CONCLUSIONS: MATS has evolved from an experimental approach into a safe and feasible surgical procedure based on the same operative approach as used for MIP. It provides an alternative to open thyroid surgery in appropriately selected cases.

Adult↗

PubMed2005

Parathyroid autotransplantation during total thyroidectomy--does the number of glands transplanted affect outcome?

Parathyroid autotransplantation is a technique for ensuring the continued function of parathyroid tissue at the time of total thyroidectomy (TT). The aim of this study was to ascertain whether the number of parathyroids transplanted affects the incidence of temporary and permanent hypoparathyroidism. A retrospective cohort study included all patients undergoing a TT in a single unit between July 1998 and June 2003. The number of parathyroids transplanted, the final pathology, and the incidence of temporary and permanent hypoparathyroidism were documented. Fisher's exact test was used for statistical analysis. A total of 1196 patients underwent a TT during the 5 years studied. Of these, 306 (25.6%) had no parathyroids transplanted, 650 (54.3%), 206 (17.2%), 34 (2.8%) had 1,2, or 3 glands autotransplanted, respectively. The incidence of temporary hypoparathyroidism was 9.8% for no gland transplants, 11.9%, 15.1%, and 31.4% for 1,2,and 3 gland transplants, respectively (p < 0.05). The incidence of permanent hypoparathyroidism was 0.98%, 0.77%, 0.97%, and 0%, respectively (p = NS). The incidence of temporary hypoparathyroidism was higher when surgery was performed for Graves' disease. Temporary hypocalcemia is closely related to the number of autotransplanted parathyroids during TT. The long-term outcome is not affected by the number of parathyroids autotransplanted. A "ready selective" approach to parathyroid autotransplantation is an effective strategy for minimizing the rate of permanent hypoparathyroidism.

Humans↗

PubMed2005

The role of a more extensive surgical approach in the initial multimodality management of papillary thyroid cancer in children.

PURPOSE: Papillary thyroid cancer (PTC) in children is rare. The optimal initial surgical treatment remains controversial, given the generally favorable overall prognosis but high rate of cervical metastasis and local recurrence. Our objective was to examine the surgical outcomes of a policy of total thyroidectomy and routine selective lymph node dissection (SLND) as the initial surgical approach to children with PTC. METHODS: This is a retrospective cohort study comprising 14 children (age, < or =17 years) with PTC referred for thyroid surgery during the past 15 years. Clinical presentation, the surgical procedure, final pathology, lymph node involvement, complications, and recurrence rates are reported. RESULTS: There were 9 females and 5 males, with an average age of 12.5 years. Seven patients (50%) had clinically apparent cervical lymphadenopathy at the time of surgical referral. All subjects underwent total thyroidectomy, and 12 (86%) had SLND. Of the 12 who underwent SLND, 10 (83%) had nodal metastases. Temporary hypocalcemia was noted in 3 of the patients (21%), and 1 patient has required ongoing intermittent calcium supplementation. All patients are alive and well at follow-up with no clinical, biochemical, or radiological evidence of local recurrence. CONCLUSIONS: Total thyroidectomy with initial SLND is an appropriate surgical approach in children with PTC. It can be done without a significantly increased risk for permanent complications and may reduce the requirement for subsequent surgical intervention for local recurrence in this young population.

Adolescent↗

PubMed2005

Experience of prophylactic thyroidectomy in multiple endocrine neoplasia type 2A kindreds with RET codon 804 mutations.

OBJECTIVE AND DESIGN: Genetic screening in multiple endocrine neoplasia type 2 (MEN 2) has led to specific management guidelines based on genotype-phenotype analysis. However, there is controversy regarding the appropriate age for prophylactic thyroidectomy in families with mutations in codon 804 in exon 14 of the RET proto-oncogene, where medullary thyroid cancer (MTC) may not develop until adulthood. We prospectively studied two MEN 2A families, one with the V804L and the other with the V804M RET mutation, to report our experience of genetic and biochemical screening and prophylactic thyroidectomy. Family 1 is one of the largest MEN 2A families in the literature, where 22 prophylactic thyroidectomies have been performed. PATIENTS AND RESULTS: C-cell hyperplasia (CCH) was found in 23 out of 25 thyroidectomy specimens from family members of ages 5 years and upwards. MTC was found in 10 out of 18 adults of age 25 years upwards, including the family 2 proband, who was found to have MTC with lymph node metastases at age 28. Phaeochromocytoma was only observed in one patient, but six cases of histologically confirmed hyperparathyroidism were seen in family 1. CONCLUSION: We suggest that prophylactic thyroidectomy should not be delayed until adulthood in MEN 2A families carrying codon 804 RET mutations, but should be performed when there is CCH, before the development of MTC, as close as possible to age 6 years, which is the age of the youngest reported case of MTC in '804' families.

Adolescent↗

PubMed2005

Simultaneous branchial cleft and thyroid disorders may present a management challenge.

BACKGROUND: Cysts, sinuses or abscesses arising from second, third or fourth branchial cleft remnants may lie either within the body of, or in close proximity to the thyroid gland. Given their infrequent nature they may pose both diagnostic and management challenges for the treating surgeon when they occur in association with thyroid disorders. METHODS: This is a case series. All patients with concomitant thyroid disorders and a branchial cleft anomaly treated in the University of Sydney Endocrine Surgical Unit in the 10-year period 1994-2003 comprised the study group. Patient demographics, clinical presentation, imaging, surgical management, definitive histology and outcomes were documented. RESULTS: Six patients were identified with an age range of 3-76 years and a male : female ratio of 1:5. Five branchial cleft anomalies were left sided, one was right sided. Two patients had second cleft anomalies, both of which were initially thought to represent metastatic lymph nodes in association with thyroid cancer. A further two patients had third cleft abnormalities presenting as suppurative thyroiditis. The final two patients had fourth cleft abnormalities causing intraoperative management problems. CONCLUSIONS: Branchial cleft remnants and anomalies are rare but may occur in association with thyroid disease. They may pose a diagnostic and management dilemma either preoperatively, when mistaken for metastatic thyroid cancer, or intraoperatively when mistaken for a thyroid nodule.

Adolescent↗

PubMed2004

Gene expression of parathyroid tumors: molecular subclassification and identification of the potential malignant phenotype.

Parathyroid tumors are heterogeneous, and diagnosis is often difficult using histologic and clinical features. We have undertaken expression profiling of 53 hereditary and sporadic parathyroid tumors to better define the molecular genetics of parathyroid tumors. A class discovery approach identified three distinct groups: (1) predominantly hyperplasia cluster, (2) HRPT2/carcinoma cluster consisting of sporadic carcinomas and benign and malignant tumors from Hyperparathyroidism-Jaw Tumor Syndrome patients, and (3) adenoma cluster consisting mainly of primary adenoma and MEN 1 tumors. Gene sets able to distinguish between the groups were identified and may serve as diagnostic biomarkers. We demonstrated, by both gene and protein expression, that Histone 1 Family 2, amyloid beta precursor protein, and E-cadherin are useful markers for parathyroid carcinoma and suggest that the presence of a HRPT2 mutation, whether germ-line or somatic, strongly influences the expression pattern of these 3 genes. Cluster 2, characterized by HRPT2 mutations, was the most striking, suggesting that parathyroid tumors with somatic HRPT2 mutation or tumors developing on a background of germ-line HRPT2 mutation follow pathways distinct from those involved in mutant MEN 1-related parathyroid tumors. Furthermore, our findings likely preclude an adenoma to carcinoma progression model for parathyroid tumorigenesis outside of the presence of either a germ-line or somatic HRPT2 mutation. These findings provide insights into the molecular pathways involved in parathyroid tumorigenesis and will contribute to a better understanding, diagnosis, and treatment of parathyroid tumors.

Gene Expression Profiling↗

PubMed2004

Parathyroidectomy for tertiary hyperparathyroidism associated with X-linked dominant hypophosphatemic rickets.

BACKGROUND: X-linked dominant hypophosphatemic rickets (XLHR) is a hereditary metabolic bone syndrome that is only beginning to be understood and is rarely associated with progression to irreversible tertiary hyperparathyroidism. We report our surgical experience with 6 patients with XLHR who underwent parathyroidectomy for associated autonomous parathyroid hyperfunction. HYPOTHESIS: Parathyroidectomy can successfully treat tertiary hyperparathyroidism in the setting of XLHR, although an understanding of expected operative findings and postoperative complications is essential. DESIGN: The study group comprised 6 patients with XLHR identified from our endocrine surgery database. Presentation, surgical procedure, parathyroid pathologic findings, and subsequent outcome are outlined. RESULTS: There were 4 women and 2 men. All were exposed to long-term vitamin D and phosphate supplementation therapy. All had persistently elevated preoperative levels of parathyroid hormone and serum calcium. The patients were treated as follows: 3 had total parathyroidectomy, 2 had 3 parathyroid glands identified and resected, and 1 had 2 abnormal parathyroid glands resected with 2 normal-appearing parathyroid glands left in situ. One patient subsequently required completion parathyroidectomy for recurrent disease. Pathologic examination results revealed hyperplasia of all resected parathyroid glands in 4 of 6 patients. One patient had a single adenoma with 3-gland hyperplasia, and 1 patient had a double adenoma. The principal complication of this procedure was profound symptomatic hypocalcemia requiring intravenous calcium infusion. Hungry bone syndrome was also observed in most subjects. Long-term, all patients achieved normocalcemia. CONCLUSION: Tertiary hyperparathyroidism is a rare but recognized complication of XLHR. Parathyroidectomy effectively treats this complication caused by autonomous parathyroid hyperfunction, but profound postoperative hypocalcemia necessitates careful management.

Adult↗

PubMed2004

Minimal-access/minimally invasive parathyroidectomy for primary hyperparathyroidism.

Minimal-access or minimally invasive parathyroidectomy is replacing a bilateral neck exploration as the surgical approach of choice in primary hyperparathyroidism (pHPT). When a parathyroid adenoma is localized preoperatively, ideally with sestamibi combined with ultrasonography, results equivalent to a bilateral neck exploration can be achieved through an incision less than 2.5 cm. Minimal-access techniques offer the advantage of cure under local anesthesia with a smaller incision and no overnight stay. Intraoperative measurement of parathyroid hormone (PTH) may be a valuable adjunct to confirmation of parathyroid adenoma removal, but currently appears to add little when preoperative localization is optimized. Controlled studies and long-term follow-up will be required to establish the true value of parathyroid minimal-access surgery.

Diagnostic Techniques, Surgical↗

PubMed2004

Minimal access thyroid surgery: technique and report of the first 25 cases.

BACKGROUND: Minimal access thyroid surgery, using various techniques, is increasingly being reported. The present study reviews our experience with thyroid surgery using a lateral focused mini-incision approach, and assesses its safety and feasibility. METHODS: The study group comprised all patients undergoing minimal access thyroid surgery (MATS) during the period May 2002-May 2003. Data were prospectively gathered, including patient demographics, indication for surgery, operation performed, nodule size, final pathology, and complications. Exclusion criteria for this procedure included: family history of thyroid cancer, previous neck irradiation or surgery, carcinoma on fine needle aspiration, presence of significant thyroiditis, multinodular goitre, and nodule size >3 cm. The operation was carried out through a 2.5-cm lateral incision placed directly over the nodule, with exposure gained by dissecting the plane between the sternomastoid muscle and the lateral edge of the strap muscles. RESULTS: Twenty-five patients underwent MATS, 22 women and three men. Nineteen patients underwent hemithyroidectomy, five underwent isthmectomy, and one underwent local nodule excision. The average measured incision size was 2.63 cm at the end of the procedure. The average nodule size was 2.2 cm, and the average thyroid lobe resected measured 4.7 cm in maximal length. Final pathology revealed benign nodules in 21 patients and four thyroid cancers (two follicular and two papillary). There was one wound infection and two patients had temporary recurrent laryngeal nerve neuropraxia. CONCLUSION: Minimal access thyroid surgery is a safe and feasible alternative to open thyroid surgery in selected cases.

Female↗

PubMed2004

Horner's syndrome in association with thyroid and parathyroid disease.

BACKGROUND: Injury to the cervical sympathetic chain and its consequence, Horner's syndrome, as a result of thyroid pathology or surgical intervention is an uncommon complication. The purpose of the present study was to examine the experience of one endocrine surgical unit with pre and postoperative Horner's syndrome. METHODS: This is a retrospective case series. The study group comprised all patients undergoing thyroid and parathyroid surgery at Royal North Shore Hospital from January 2000 to October 2003 who were identified as having either pre or postoperative Horner's syndrome. Patient demographics, operation performed, underlying pathology and outcomes were evaluated. RESULTS: There were nine cases of Horner's syndrome recorded from a total of 2208 thyroid and parathyroid operations undertaken: three with preoperative Horner's, an incidence of 0.14%, six with postoperative Horner's, an incidence of 0.27%. Patients ranged in age from 22 to 87 years. Two of the three preoperative cases were related to benign pathology, the remaining case having anaplastic carcinoma. Five of the six postoperative cases were related to thyroid malignancy with lymph node dissection; one case was associated with benign parathyroid pathology. CONCLUSIONS: Cervical sympathetic chain injury is a rare complication of surgery for thyroid and parathyroid conditions. The presence of preoperative Horner's does not necessarily indicate an underlying malignancy.

Adult↗

PubMed2003

Clinical and molecular aspects of adrenocortical tumourigenesis.

Adrenal masses are a common problem affecting 3-7% of the population. The majority turn out to be benign adrenocortical adenomas, which may be functional or non-functional. Much more rarely, these masses represent a primary adrenal carcinoma. It is becoming increasingly recognized that of the benign functioning adenomas or hyperplasias, the majority will hypersecrete aldosterone and this will be more frequently detected when hypertensive populations are screened for this disease. In contrast, the incidence of primary adrenocortical carcinoma has remained steady and for this disease, surgery represents the mainstay of treatment. The advent of laparoscopic adrenal surgery has lowered the threshold size for recommending surgery for asymptomatic adrenal masses and as such, an increased proportion of adrenocortical cancers are being resected and detected at an earlier stage. Recent progress has been made in our understanding of the key genetic changes which underpin the biology of this disease. Progression from adrenal adenoma to carcinoma involves a monoclonal proliferation of cells which, among other defects, have undergone chromosomal duplication at the 11p15.5 locus leading to overexpression of the IGF2 gene and abrogation of expression of the CDKN1C and H19 genes. TP53 is involved in progression to carcinoma in a subset of patients and the frequency of ACTH receptor deletion needs to be more fully explored. Other key oncogenes and tumour suppressor genes remain to be identified although the chromosomal loci in which they lie can be identified at 17p, 1p, 2p16 and 11q13 for tumour suppressor genes and chromosomes 4, 5 and 12 for oncogenes.

Adrenal Cortex Neoplasms↗

PubMed2002

Increase in presentations and procedure rates for hyperparathyroidism in Northern Sydney and New South Wales.

OBJECTIVE: To examine changes in presentation of primary hyperparathyroidism and rates of parathyroidectomy in Northern Sydney (the Northern Sydney Area Heath Service) and New South Wales (NSW). DESIGN: Retrospective case series January 1962 - December 2001 and audit of the NSW Department of Health inpatient database (1993-1999). SETTING: University of Sydney Endocrine Surgical Unit, Royal North Shore Hospital. PARTICIPANTS: 1613 patients undergoing parathyroidectomy during the study period. MAIN OUTCOME MEASURES: Age-standardised parathyroidectomy rates and indications for surgical intervention. RESULTS: The age-standardised rates of parathyroidectomy for primary hyperparathyroidism in women have increased significantly in Northern Sydney from 0.14 cases per 100,000 in 1976 to 7.7 cases per 100,000 in 1996 (P < 0.001). In NSW there has been an increase in parathyroidectomy rates in women from 5.1 cases per 100,000 in 1993 to 12.3 cases per 100,000 in 1998 (P < 0.001). Osteoporosis was the most common overall indication for surgery in Northern Sydney, accounting for 27% of all cases. The proportion of cases presenting with osteoporosis increased significantly from 4% in 1962-1980 to 34% over the past decade (P < 0.001). CONCLUSIONS: The rate of parathyroidectomy procedures has increased markedly in Northern Sydney and in NSW. The investigation of osteoporosis has led to the diagnosis of primary hyperparathyroidism in an increasing proportion of cases and has contributed to the growing surgical referral rates.

Adult↗