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Isaacs JD, McMullen TPW, Sidhu SB, Sywak MS, Robinson BG, Delbridge LW. Predictive value of the Delphian and level VI nodes in papillary thyroid cancer. ANZ J Surg 2011; 80:834-8. [PMID: 20969694 DOI: 10.1111/j.1445-2197.2010.05334.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Recent published data has shown that metastatic involvement of the prelaryngeal or Delphian lymph node (DLN), the highest of the central (level VI) cervical lymph nodes, is highly predictive of advanced nodal disease in papillary thyroid cancer (PTC). The aims of this study were to determine the diagnostic accuracy of all the level VI cervical nodes in PTC and to determine which node group, if any, is the most accurate in predicting lateral node (N1b) disease. METHODS This was a retrospective cohort study. Data were obtained from the University of Sydney Endocrine Surgical Unit Database and through a review of the histopathology records. The study cohort was composed of 177 consecutive patients with a final diagnosis of PTC who underwent total thyroidectomy and lymph node dissection, spanning the period from May 2001 to December 2006. RESULTS Of the 177 patients with PTC, 86 had the DLN removed, 51 had a pretracheal node removed and 76 had the paratracheal group removed. DLN, paratracheal and pretracheal node disease was present in 21%, 39% and 46%, respectively. Lateral node (N1b) disease was present in 35%. Paratracheal node involvement was mildly predictive of further disease with patients 1.7 times more likely to have lateral node involvement (sensitivity=55%, specificity=68%). Pretracheal node involvement was moderately predictive of further disease with patients three times more likely to have lateral node involvement (sensitivity=72%, specificity=74%). DLN involvement was highly predictive of further node involvement with patients nine times more likely to have lateral node disease (sensitivity=53%, specificity=94%) and 40 times more likely to have any nodal disease (sensitivity=41%, specificity=100%). CONCLUSION This is the first study to examine the diagnostic accuracy of all level VI lymph nodes in PTC. While, metastatic involvement of all central nodal groups is indicative of further disease, the DLN is the most accurate predictor.
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O'Neill CJ, Bullock M, Chou A, Sidhu SB, Delbridge LW, Robinson BG, Gill AJ, Learoyd DL, Clifton-Bligh R, Sywak MS. BRAF(V600E) mutation is associated with an increased risk of nodal recurrence requiring reoperative surgery in patients with papillary thyroid cancer. Surgery 2011; 148:1139-45; discussion 1145-6. [PMID: 21134544 DOI: 10.1016/j.surg.2010.09.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 09/14/2010] [Indexed: 11/28/2022]
Abstract
BACKGROUND The role of the B-isoform of the Raf kinase (BRAF) mutation BRAF(V600E) as an independent prognostic factor in papillary thyroid cancer (PTC) remains controversial. Some studies suggest that tumors containing BRAF(V600E) have decreased radioiodine avidity and present a greater risk of nodal recurrence and distant metastases. METHODS Paraffin-embedded specimens from consecutive patients who underwent surgery for PTC before 2003 were independently reviewed by an endocrine pathologist. DNA was extracted, amplified by polymerase chain reaction, and the presence of the BRAF(V600E) mutation was determined by restriction digest. Tumor characteristics and long-term disease outcomes were analyzed according to BRAF(V600E) status. RESULTS BRAF(V600E) was identified in 60 (59%) of 101 patients. At a median follow-up of 106 months, the overall disease-free survival was 78%. Clinically evident nodal recurrence occurred in 11% of BRAF(V600E)-positive patients, and all patients required lateral neck dissection (P = .02). In contrast, subclinical nodal recurrence occurred in 7% of BRAF(V600E)-negative patients, and all recurrences were successfully ablated with radioactive iodine. There was a trend toward poorer disease-free survival among patients with stage III/IV PTC and BRAF(V600E) mutation (P = .08). All 5 disease-related deaths occurred in patients with BRAF(V600E)-positive primary tumors (P = .06). CONCLUSION The BRAF(V600E) mutation in PTC is associated with an increased risk of palpable nodal recurrence and the need for reoperative surgery.
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Oucharek JJ, O’Neill CJ, Suliburk JW, Sywak MS, Delbridge LW, Sidhu SB. Durability of Focused Minimally Invasive Parathyroidectomy in Young Patients with Sporadic Primary Hyperparathyroidism. Ann Surg Oncol 2010; 18:1290-2. [DOI: 10.1245/s10434-010-1417-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Indexed: 11/18/2022]
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McMullen TPW, Learoyd DL, Williams DC, Sywak MS, Sidhu SB, Delbridge LW. Hyperparathyroidism in pregnancy: options for localization and surgical therapy. World J Surg 2010; 34:1811-6. [PMID: 20386905 DOI: 10.1007/s00268-010-0569-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Hyperparathyroidism in pregnancy is a threat to the health of both mother and fetus. The mothers suffer commonly from nephrolithiasis, hyperemesis, or even hypercalcemic crisis. Untreated disease will commonly complicate fetal development and fetal death is a significant risk. Treatment options, including medical and surgical therapy, are debated in the literature. METHODS This is a case series comprising seven patients with primary hyperparathyroidism in pregnancy. Data collected included symptoms at diagnosis, biochemical abnormalities, pathologic findings, treatment regimes, and subsequent maternal and fetal outcomes. RESULTS Seven women, aged 20 to 39 years, presented with hyperparathyroidism during pregnancy. The earliest presented at 8 weeks and the latest at 38 weeks. Four of seven patients experienced renal calculi. Calcium levels were 2.7-3.5 mmol/l. All were found to have solitary parathyroid adenomas, of which two were in ectopic locations. Fetal complications included three preterm deliveries and one fetal death with no cases of neonatal tetany. Maternal and fetal complications could not be predicted based on duration or severity of hypercalcemia. Three patients were treated during pregnancy with surgery, and two of these had ectopic glands that required reoperations with a novel approach using Tc-99m sestamibi scanning during pregnancy to assist in localizing the abnormal gland. Four cases were treated postpartum with a combination of open and minimally invasive approaches after localization. No operative complications or fetal loss related to surgery were observed in this cohort. CONCLUSIONS Primary hyperparathyroidism in pregnancy represents a significant risk for maternal and fetal complications that cannot be predicted by duration of symptoms or serum calcium levels. Surgical treatment should be considered early, and a minimally invasive approach with ultrasound is best suited to mitigating risk to mother and fetus. Equally important, Tc-99m sestamibi imaging may be used safely for localization of the parathyroids after negative cervical explorations.
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O'Neill CJ, Chang LY, Suliburk JW, Sidhu SB, Delbridge LW, Sywak MS. Sutureless thyroidectomy: surgical technique. ANZ J Surg 2010; 81:515-8. [DOI: 10.1111/j.1445-2197.2010.05493.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Suliburk JW, Sywak MS, Sidhu SB, Delbridge LW. 1000 minimally invasive parathyroidectomies without intra-operative parathyroid hormone measurement: lessons learned. ANZ J Surg 2010; 81:362-5. [PMID: 21518187 DOI: 10.1111/j.1445-2197.2010.05488.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Minimally invasive parathyroidectomy (MIP) has become the procedure of choice in the treatment of primary hyperparathyroidism where a single adenoma can be localized preoperatively. The role for intra-operative parathyroid hormone measurement (IOPTH) is controversial. Some experts recommend that IOPTH is a mandatory requirement for successful MIP while others state that the technique is not needed. We reviewed 10 years of MIP in a single unit without the use of IOPTH in order to examine causes of failure. METHODS This study is a retrospective review of the University of Sydney Endocrine Surgery Database from May of 1998 to August of 2008. The database was queried for MIPs performed as well as for failed operations. Patient record analysis was completed to determine the reason for failure of the operation. RESULTS In the period January 1998 to August 2008, a total of 2343 parathyroidectomy procedures were performed. Of these, 1020 were MIPs with 23 (2.2%) failures. One patient was found to have benign familial hypercalcemia, whereas five were lost to follow-up. Reasons for failure in the remaining 17 patients were: 10 patients (59%) were found to have double adenomas, 3 (17%) patients with hyperplasia and 4 (24%) patients with single gland disease were missed at initial operation. All 17 were cured on repeat exploration. CONCLUSION MIP can be performed safely and with 98% success without the need for IOPTH. The most common cause of failure after MIP is an occult double adenoma. Given that repeat sestamibi scan correctly identifies persistent disease in most cases, consideration can be given to MIP as a choice of procedure for repeat operation.
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Bargren AE, Meyer-Rochow GY, Sywak MS, Delbridge LW, Chen H, Sidhu SB. Diagnostic utility of fine-needle aspiration cytology in pediatric differentiated thyroid cancer. World J Surg 2010; 34:1254-60. [PMID: 20091309 DOI: 10.1007/s00268-010-0391-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Pediatric patients present with thyroid nodules less often than adults, but the rate of malignancy is much higher. This study was designed to determine the ability of fine-needle aspiration cytology (FNA) to diagnose accurately and facilitate management of thyroid neoplasms in pediatric patients. METHODS A retrospective study revealed 110 patients <19 years old who had undergone thyroid surgery and FNA biopsy at two academic institutions over the last 28 years. FNA sensitivity for diagnosing papillary thyroid cancer (PC) and follicular neoplasm (FN) was investigated. RESULTS Of 110 patients who presented for surgery, 27 had PC and 33 had a FN: 4 follicular carcinomas (FCs) and 29 follicular adenomas (FAs). Among the PCs patients, the FNA results were as follows: 1 (4%) nondiagnostic, 6 (22%) atypical, 2 (7%) benign, and 18 (67%) malignant lesions. The sensitivity of a malignant FNA was 90% for diagnosing a PC. Sensitivity of an atypical FNA was 75% for FCs and 69% for FAs, giving an overall FN sensitivity of 70%. Of the atypical FNA readings, 60% had confirmed histological atypical features, and 19% were malignant. In 95% of the malignant FNA reports, final histology confirmed PC, resulting in a positive predictive value of 95%. CONCLUSIONS FNA biopsy can reliably diagnose malignancy in pediatric thyroid patients and should be used as a standard technique to indicate surgical treatment. Atypical or suspicious FNA results do not predict cancer effectively, confirming the current accepted practice for adults that diagnostic excision is required to exclude malignancy in pediatric patients.
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Delbridge LW. Sutureless thyroidectomy- technological advance or toy? ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 2009; 144:1174-1175. [PMID: 20030037 DOI: 10.1001/archsurg.2009.199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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Meyer-Rochow GY, Schembri GP, Benn DE, Sywak MS, Delbridge LW, Robinson BG, Roach PJ, Sidhu SB. The utility of metaiodobenzylguanidine single photon emission computed tomography/computed tomography (MIBG SPECT/CT) for the diagnosis of pheochromocytoma. Ann Surg Oncol 2009; 17:392-400. [PMID: 19949879 DOI: 10.1245/s10434-009-0850-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Indexed: 01/02/2023]
Abstract
BACKGROUND The enhancement of metaiodobenzylguanidine single photon emission computed tomography (MIBG SPECT) imaging through the addition of CT images fused with SPECT data (coregistered MIBG SPECT/CT imaging) is new technology that allows direct correlation of anatomical and functional information. We hypothesized that MIBG SPECT/CT imaging would provide additional information and improve diagnostic confidence for the radiological localization of a pheochromocytoma, in particular for patients at high risk of multifocal or recurrent disease. METHODS A retrospective study of all patients investigated by MIBG SPECT/CT at our institution from 2006 to 2008 for a suspected pheochromocytoma was performed. Each case was compared with conventional radiological investigations to determine whether MIBG SPECT/CT was able to improve diagnostic confidence and provide additional diagnostic information compared with conventional imaging alone. RESULTS Twenty-two patients had MIBG SPECT/CT imaging for a suspected pheochromocytoma. Fourteen patients had positive MIBG SPECT/CT imaging results correlating with imaging by CT or magnetic resonance imaging in all cases. In six cases, MIBG SPECT/CT provided additional information that altered the original radiological diagnosis. Five patients with a pheochromocytoma-associated germline mutation had multifocal disease excluded by MIBG SPECT/CT. Patients without a germline mutation that had positive biochemistry and a solitary lesion with conventional imaging had no diagnostic improvement with MIBG SPECT/CT imaging. CONCLUSIONS MIBG SPECT/CT fusion imaging is a sensitive and specific radiological imaging tool for patients suspected to have pheochromocytoma. The particular strengths of MIBG SPECT/CT are detection of local recurrence, small extra-adrenal pheochromocytomas, multifocal tumors, or the presence of metastatic disease.
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Meyer-Rochow GY, Soon PSH, Delbridge LW, Sywak MS, Bambach CP, Clifton-Bligh RJ, Robinson BG, Sidhu SB. Outcomes of minimally invasive surgery for phaeochromocytoma. ANZ J Surg 2009; 79:367-70. [PMID: 19566519 DOI: 10.1111/j.1445-2197.2009.04891.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Laparoscopic adrenalectomy is now accepted as the procedure of choice for the resection of benign adrenocortical tumours, but few studies have assessed whether the outcomes of laparoscopic adrenalectomy for adrenal phaeochromocytoma are similar to that of other adrenal tumour types. This is a retrospective cohort study. Clinical and operative data were obtained from an adrenal tumour database and hospital records. A total of 191 patients had laparoscopic adrenalectomy, of which 36 were for phaeochromocytoma, over a 12-year period. Length of hospital stay (4.8 vs 3.6 days, P= 0.03) and total operating times (183 vs 157 min, P= 0.01) were greater in the laparoscopic phaeochromocytoma resection group. Despite the greater size of the phaeochromocytomas compared to the remaining adrenal tumour types (44 mm vs 30 mm, P < 0.01), however, rate of conversion and morbidity were no different. Laparoscopic adrenalectomy for phaeochromocytoma is a safe procedure with similar outcomes to laparoscopic adrenalectomy for other adrenal tumour types.
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Bargren AE, Meyer-Rochow GY, Delbridge LW, Sidhu SB, Chen H. Outcomes of Surgically Managed Pediatric Thyroid Cancer. J Surg Res 2009; 156:70-3. [DOI: 10.1016/j.jss.2009.03.088] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 03/29/2009] [Accepted: 03/31/2009] [Indexed: 10/20/2022]
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Tan CT, Meyer-Rochow GY, Sywak MS, Delbridge LW, Sidhu SB. Reoperative adrenal surgery: lessons learnt. ANZ J Surg 2009; 79:371-7. [PMID: 19566520 DOI: 10.1111/j.1445-2197.2009.04892.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the widespread use of abdominal imaging, the detection and therefore incidence of adrenal tumours is increasing. The laparoscopic approach to primary surgical resection of adrenal tumours has now become the standard of care. There is scarce published literature regarding the management and outcomes of recurrent adrenal tumours. The aim of the present study was therefore to review the authors' experience with reoperative adrenal surgery. A retrospective review of reoperative adrenalectomy cases identified from the prospectively maintained University of Sydney Endocrine Surgical Unit Database from January 1988 to July 2007 was carried out. There were nine (3.5%) reoperative adrenalectomies in six patients. Two were cases of adrenocortical carcinoma, two involved cases of familial phaeochromocytomas and two cases were due to sporadic phaeochromocytomas. Reoperative adrenal surgery is an uncommon event. During the index surgery for adrenal tumours, all adrenal tissue should be removed and knowledge of the vagaries of adrenal anatomy is essential. Reoperative adrenal surgery is a safe procedure and may confer survival benefit or symptom relief. Lifelong follow up is essential for all patients who have had surgery for functional and malignant adrenal tumours.
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Howell VM, Gill A, Clarkson A, Nelson AE, Dunne R, Delbridge LW, Robinson BG, Teh BT, Gimm O, Marsh DJ. Accuracy of combined protein gene product 9.5 and parafibromin markers for immunohistochemical diagnosis of parathyroid carcinoma. J Clin Endocrinol Metab 2009; 94:434-41. [PMID: 19017757 DOI: 10.1210/jc.2008-1740] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT Parafibromin, encoded by HRPT2, is the first marker with significant benefit in the diagnosis of parathyroid carcinoma. However, because parafibromin is only involved in up to 70% of parathyroid carcinomas and loss of parafibromin immunoreactivity may not be observed in all cases of HRPT2 mutation, a complementary marker is needed. OBJECTIVE We sought to determine the efficacy of increased expression of protein gene product 9.5 (PGP9.5), encoded by ubiquitin carboxyl-terminal esterase L1 (UCHL1) as an additional marker to loss of parafibromin immunoreactivity for the diagnosis of parathyroid carcinoma. DESIGN In total, 146 parathyroid tumors and nine normal tissues were analyzed for the expression of parafibromin and PGP9.5 by immunohistochemistry and for UCHL1 by quantitative RT-PCR. These samples included six hyperparathyroidism-jaw tumor syndrome-related tumors and 24 sporadic carcinomas. RESULTS In tumors with evidence of malignancy, strong staining for PGP9.5 had a sensitivity of 78% for the detection of parathyroid carcinoma and/or HRPT2 mutation and a specificity of 100%. Complete lack of nuclear parafibromin staining had a sensitivity of 67% and a specificity of 100%. PGP9.5 was positive in a tumor with the HRPT2 mutation L64P that expressed parafibromin. Furthermore, UCHL1 was highly expressed in the carcinoma/hyperparathyroidism-jaw tumor syndrome group compared to normal (P < 0.05) and benign specimens (P < 0.001). CONCLUSION These results suggest that positive staining for PGP9.5 has utility as a marker for parathyroid malignancy, with a slightly superior sensitivity (P = 0.03) and similar high specificity to that of parafibromin.
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Sywak MS, Yeh MW, McMullen T, Stalberg P, Low H, Alvarado R, Sidhu SB, Delbridge LW. A randomized controlled trial of minimally invasive thyroidectomy using the lateral direct approach versus conventional hemithyroidectomy. Surgery 2008; 144:1016-21; discussion 1021-2. [DOI: 10.1016/j.surg.2008.07.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Accepted: 07/30/2008] [Indexed: 11/28/2022]
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Alvarado R, McMullen T, Sidhu SB, Delbridge LW, Sywak MS. Minimally invasive thyroid surgery for single nodules: an evidence-based review of the lateral mini-incision technique. World J Surg 2008; 32:1341-8. [PMID: 18373119 DOI: 10.1007/s00268-008-9554-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Minimally invasive thyroidectomy techniques are being developed in an effort to minimize pain, shorten the length of hospital stay, and improve cosmesis. Various minimally invasive thyroid surgery (MITS) techniques have been shown to be safe and feasible with some benefits in terms of cosmesis and pain outcomes; however, no single technique has been broadly accepted. This study was designed to review the evidence in relation to MITS and our experience with the direct lateral mini-incision technique. METHODS A review of literature published until December 2007 on minimally invasive thyroidectomy techniques was undertaken. Three issues were addressed: 1) Does MITS provide any benefit compared with conventional open thyroidectomy? 2) Is there any advantage to the use of endoscopic or video-assisted techniques compared with the direct mini-incision technique? 3) Is the lateral mini-incision technique safe and efficacious? Additional data in relation to the above issues was derived from a retrospective cohort study of patients undergoing mini-incision thyroid surgery within our unit. RESULTS Issue 1: Five prospective randomized studies and eight studies at a lower level of evidence have demonstrated consistent advantages of MITS compared with open thyroid surgery in terms of reduced pain and improved cosmesis with equivalent operative safety. Issue 2: In compiling four level III and IV studies that compared open and video-assisted minimally invasive surgery, there do not seem to be significant differences in patient satisfaction with the incision. The video-assisted approaches require significantly longer operative times but also seem to be less painful. Issue 3: Three cohort studies (level IV) have demonstrated that the lateral mini-incision technique is both safe and efficacious compared with open surgery for hemi-thyroidectomy. Data from our cohort study of 1281 patients (open hemi-thyroidectomy 1054 vs. MITS 227) confirmed MITS to be a safe and effective procedure. The rate of postoperative hematoma formation and wound infection was equivalent between groups. The rate of permanent recurrent laryngeal nerve injury was 0.4% for MITS and 0.3% for CHT and not significantly different (p = 0.7). CONCLUSIONS MITS has demonstrated advantages over conventional open approaches for both hemi- and total thyroidectomy and the benefits do not depend on the open or video-assisted approach. For thyroid lobectomies, the lateral mini-incision approach can be performed with an operative time and postoperative complication profile equivalent to conventional hemi-thyroidectomy while providing excellent cosmesis with a 2-3 cm scar.
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Lu M, Forsberg L, Höög A, Juhlin CC, Vukojević V, Larsson C, Conigrave AD, Delbridge LW, Gill A, Bark C, Farnebo LO, Bränström R. Heterogeneous expression of SNARE proteins SNAP-23, SNAP-25, Syntaxin1 and VAMP in human parathyroid tissue. Mol Cell Endocrinol 2008; 287:72-80. [PMID: 18457912 DOI: 10.1016/j.mce.2008.01.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Revised: 12/26/2007] [Accepted: 01/26/2008] [Indexed: 11/16/2022]
Abstract
In regulated exocytosis synaptosomal-associated protein of 25kDa (SNAP-25) is one of the key-players in the formation of SNARE (soluble N-ethylmaleimide-sensitive fusion attachment protein receptor) complex and membrane fusion. SNARE proteins are essentially expressed in neurons, neuroendocrine and endocrine cells. Whether parathyroid cells express these proteins is not known. In this study, we have examined the expression of the SNARE protein SNAP-25 and its cellular homologue SNAP-23, as well as syntaxin1 and VAMP (vesicle-associated membrane protein) in samples of normal parathyroid tissue, chief cell adenoma, and parathyroid carcinoma, using immunohistochemistry and Western blot analysis. SNAP-23 and VAMP were evenly expressed in all studied parathyroid tissues using immunohistochemistry and/or Western blot analysis. SNAP-25 (and Syntaxin1) was not expressed in normal parathyroid tissue, but in approximately 20% of chief cell adenomas, and in approximately 45% of parathyroid carcinoma samples. It is likely that the SNARE proteins SNAP-23 and VAMP play a role in the stimulus-secretion coupling and exocytosis of parathyroid hormone as these proteins were expressed in all of the parathyroid samples we studied. In particular, preferential expression of SNAP-23 rather than SNAP-25 provides an explanation of the high level of PTH secretion that occurs under conditions of low cytoplasmic free Ca(2+) concentration (around 0.1micromol/l). SNAP-25 (and Syntaxin1) appears to be a tumour-specific protein(s) in parathyroid tissues since its expression was restricted to pathological tissues.
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Delbridge LW, Palazzo FF. First parathyroid surgeon: Sir John Bland-Sutton and the parathyroids. ANZ J Surg 2008; 77:1058-61. [PMID: 17973666 DOI: 10.1111/j.1445-2197.2007.04324.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Felix Mandl from Vienna has long been acclaimed as having carried out the first parathyroidectomy for primary hyperparathyroidism in 1925. He was not, however, the first surgeon to have seen the parathyroid glands, either at surgery or in the pathology laboratory. There is evidence that the first intentional removal of a parathyroid tumour was probably carried out at the Middlesex Hospital, London, UK, by Sir John Bland-Sutton at least a decade earlier. Indeed, Sir John Bland-Sutton appeared to have been very much aware of the parathyroid gland and the pathology associated with it for many years, even before this first parathyroid operation. He described a post-mortem specimen of a parathyroid tumour in 1886; he surgically removed a parathyroid cyst in 1909; and then carried out an intentional parathyroidectomy for a parathyroid tumour some time before 1917.
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Soon PSH, Yeh MW, Delbridge LW, Bambach CP, Sywak MS, Robinson BG, Sidhu SB. Laparoscopic surgery is safe for large adrenal lesions. Eur J Surg Oncol 2008; 34:67-70. [PMID: 17532597 DOI: 10.1016/j.ejso.2007.03.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 03/07/2007] [Indexed: 10/23/2022] Open
Abstract
INTRODUCTION Laparoscopic adrenalectomy has surpassed open adrenalectomy as the gold standard for excision of benign adrenal lesions. The size threshold for offering laparoscopic adrenalectomy is controversial as the prevalence of adrenocortical carcinoma increases with increasing tumour size. The aim of this paper was to assess the safety of laparoscopic adrenalectomy for large adrenal tumours (tumours > or = 60 mm). METHODS A retrospective cohort study of patients who underwent adrenalectomy in a single unit during the period 1995-2005 was undertaken. RESULTS One hundred and seventy patients with 173 tumours were included in this study. Of these, 29 were > or = 60 mm in size, and 16 of these patients underwent laparoscopic adrenalectomy. There were 8 adrenocortical carcinomas in the group with tumours > or = 60 mm in size. Five of these patients underwent an open adrenalectomy, while 2 and 1 patients had laparoscopic and laparoscopic converted to open adrenalectomy respectively. Four of the patients undergoing open adrenalectomy died of their disease while 1 is alive with recurrence 3 years later. The 3 patients who underwent either laparoscopic or laparoscopic converted to open adrenalectomy are alive without evidence of disease after 18 months follow up. CONCLUSION Our data show that patients with tumours > or = 60 mm with no preoperative or intraoperative evidence of malignancy can undergo laparoscopic adrenalectomy without evidence of recurrence on short term follow up. These findings are concordant with the growing body of literature supporting laparoscopic adrenalectomy for potentially malignant tumours > or = 60 mm in size without preoperative or intraoperative features of malignancy.
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Pang TC, Bambach C, Monaghan JC, Sidhu SB, Bune A, Delbridge LW, Sywak MS. Outcomes of laparoscopic adrenalectomy for hyperaldosteronism. ANZ J Surg 2007; 77:768-73. [PMID: 17685956 DOI: 10.1111/j.1445-2197.2007.04225.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Primary hyperaldosteronism is a frequent cause of resistant hypertension and is amenable to surgical intervention when caused by a unilateral aldosterone-producing adenoma. The aim of this study was to investigate the long-term results of laparoscopic adrenalectomy in the control of hypertension caused by primary hyperaldosteronism. METHODS A prospective case series of patients undergoing laparoscopic adrenalectomy for hyperaldosteronism was studied. Blood pressure (BP), serum aldosterone levels, plasma renin activity, serum potassium and antihypertensive requirement were measured before and after adrenalectomy. RESULTS Sixty-two patients with hyperaldosteronism underwent laparoscopic adrenalectomy in the period from December 1995 to August 2005. The median follow up was 59 months. There was a significant decrease in both systolic blood pressure and diastolic blood pressure at final follow up compared with that before operation. Systolic blood pressure decreased from 149 mmHg to 129 mmHg at final follow up (P < 0.0001). Diastolic blood pressure decreased from 89 mmHg to 80 mmHg (P < 0.0001). Antihypertensive requirement was decreased from an average of 2.6 separate medications preoperatively to 1.4 medications at final follow up (P < 0.0001). Serum aldosterone levels were significantly lower (698 (confidence interval 534-862) pg/mL vs 181 (confidence interval 139-225) pg/mL, P < 0.0001). Overall, 34% of patients had cure of hypertension and did not require any antihypertensive agent. A further 51% had improvement in BP control, whereas 5% had no change or had worsening hypertension. Multivariate regression analysis showed that age and gland size were independent factors predicting sustained hypertension after surgery. CONCLUSION In appropriately selected patients with primary hyperaldosteronism, laparoscopic adrenalectomy is effective in improving long-term BP control. Larger adrenal gland size and older age at time of surgery are predictors of persisting hypertension.
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Meyer-Rochow GY, Alvarado R, Sywak MS, Sidhu SB, Delbridge LW, Gill AJ. Letter 2: Intraoperative diagnosis and treatment of parathyroid cancer and atypical parathyroid adenoma (Br J Surg 2007; 94: 566-570). Br J Surg 2007; 94:1043; author reply 1043-4. [PMID: 17636522 DOI: 10.1002/bjs.5974] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Sywak MS, Palazzo FF, Yeh M, Wilkinson M, Snook K, Sidhu SB, Delbridge LW. PARATHYROID HORMONE ASSAY PREDICTS HYPOCALCAEMIA AFTER TOTAL THYROIDECTOMY. ANZ J Surg 2007; 77:667-70. [PMID: 17635281 DOI: 10.1111/j.1445-2197.2007.04183.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Postoperative parathyroid gland function after total thyroidectomy (TT) has traditionally been monitored by the measurement of serum calcium concentrations. The purpose of this study is to determine whether measurement of parathyroid hormone (PTH) concentrations in the early postoperative period accurately predicts patients at risk of developing hypocalcaemia. METHODS A prospective cohort study of patients undergoing TT was carried out. PTH concentrations were measured preoperatively and at 4 and 23 h postoperatively. Serum calcium concentration was measured preoperatively and twice daily for 48 h after surgery. RESULTS One hundred patients undergoing TT were recruited into the study in the period June 2004 to July 2005. Benign multinodular goitre was the most common indication for surgery (77%). The incidence of temporary hypocalcaemia (Ca < 2.0 mmol/L) was 18%. The mean PTH concentration at 4 h after surgery was 22.3 ng/L and was not significantly different from the 23-h concentration of 23.2 ng/L (P = 0.18). A PTH concentration of < or = 3 ng/L measured at 4 h after surgery had a sensitivity, specificity and likelihood ratio of 0.71, 0.94 and 11.3, respectively, for predicting postoperative hypocalcaemia. The accuracy of a single PTH concentration at 4 h was good for predicting hypocalcaemia (area under receiver-operator characteristic curve 0.90; confidence interval 0.81-0.96). There was no significant difference in accuracy between the 4- and 24-h PTH concentrations (P = 0.14). CONCLUSIONS A single measurement of PTH concentration in the early postoperative period after TT reliably predicts patients who are likely to develop hypocalcaemia. This approach facilitates early discharge and may decrease the need for multiple postoperative blood tests.
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Loch-Wilkinson TJ, Stalberg PLH, Sidhu SB, Sywak MS, Wilkinson JF, Delbridge LW. Nerve stimulation in thyroid surgery: is it really useful? ANZ J Surg 2007; 77:377-80. [PMID: 17497981 DOI: 10.1111/j.1445-2197.2007.04065.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Monitoring of the recurrent laryngeal nerve (RLN) has been claimed in some studies to reduce rates of nerve injury during thyroid surgery compared with anatomical dissection and visual identification of the RLN alone, whereas other studies have found no benefit. Continuous monitoring with endotracheal electrodes is expensive whereas discontinuous monitoring by laryngeal palpation with nerve stimulation is a simple and inexpensive technique. This study aimed to assess the value of nerve stimulation with laryngeal palpation as a means of identifying and assessing the function of the RLN and external branch of the superior laryngeal nerve (EBSLN) during thyroid surgery. METHODS This was a prospective case series comprising 50 consecutive patients undergoing total thyroidectomy providing 100 RLN and 100 EBSLN for examination. All patients underwent preoperative and postoperative vocal cord and voice assessment by an independent ear, nose and throat surgeon, laryngeal examination at extubation and all were asked to complete a postoperative dysphagia score sheet. Dysphagia scores in the study group were compared with a control group (n = 20) undergoing total thyroidectomy without nerve stimulation. RESULTS One hundred of 100 (100%) RLN were located without the use of the nerve stimulator. A negative twitch response occurred in seven (7%) RLN stimulated (two bilateral, three unilateral). Postoperative testing, however, only showed one true unilateral RLN palsy postoperatively (1%), which recovered in 7 weeks giving six false-positive and one true-positive results. Eighty-six of 100 (86%) EBSLN were located without the nerve stimulator. Thirteen of 100 (13%) EBSLN could not be identified and 1 of 100 (1%) was located with the use of the nerve stimulator. Fourteen per cent of EBSLN showed no cricothyroid twitch on EBSLN stimulation. Postoperative vocal function in these patients was normal. There were no instances of equipment malfunction. Dysphagia scores did not differ significantly between the study and control groups. CONCLUSION Use of a nerve stimulator did not aid in anatomical dissection of the RLN and was useful in identifying only one EBSLN. Discontinuous nerve monitoring by stimulation during total thyroidectomy confers no obvious benefit for the experienced surgeon in nerve identification, functional testing or injury prevention.
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Meyer-Rochow GY, Sywak MS, Reeve TS, Delbridge LW, Sidhu SB. Surgical trends in the management of thyroid lymphoma. Eur J Surg Oncol 2007; 34:576-80. [PMID: 17604588 DOI: 10.1016/j.ejso.2007.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2006] [Accepted: 04/28/2007] [Indexed: 02/08/2023] Open
Abstract
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.
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Soon PSH, Yeh MW, Sywak MS, Roach P, Delbridge LW, Sidhu SB. Minimally invasive parathyroidectomy using the lateral focused miniincision approach: Is there a learning curve for surgeons experienced in the open procedure? J Am Coll Surg 2007; 204:91-5. [PMID: 17189117 DOI: 10.1016/j.jamcollsurg.2006.10.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 09/04/2006] [Accepted: 10/17/2006] [Indexed: 11/20/2022]
Abstract
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.
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Grodski S, Stalberg P, Robinson BG, Delbridge LW. Surgery versus radioiodine therapy as definitive management for graves' disease: the role of patient preference. Thyroid 2007; 17:157-60. [PMID: 17316118 DOI: 10.1089/thy.2006.0141] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Thyroidectomy is an option for the definitive management of Graves' disease. The aim of this study was to examine the role of patient preference for selecting surgery as definitive treatment. PATIENTS AND METHODS This is a retrospective cohort study comprising all patients (n = 63) presenting to a single surgeon for surgical management of Graves' disease over 3 years. Documented reasons for surgery were compared with accepted indications, as well as patients' perceptions as assessed by questionnaire. RESULTS The most frequent absolute indication was the presence of a large goiter (n = 8; 13%) or associated thyroid nodule (n = 6; 10%). Ophthalmopathy, a relative indication, comprised the largest single group overall (n = 18; 29%); however, a significant number of patients (n = 17; 27%) elected surgery in the absence of a recognized indication. There was strong concordance (73%) between the recorded indication and the patients' survey response. Overall, there was a high level of satisfaction with surgery with 88% of respondents giving a satisfaction score of 7 or greater on a visual analog scale (VAS) (0-10). CONCLUSIONS One-third of all patients electing surgery as definitive management do so in the absence of a specific indication. Overall, there is a high level of satisfaction with the decision for surgery as definitive management of Graves' disease.
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