Validity and limits of intraoperative parathyroid hormone monitoring during minimally invasive parathyroidectomy: a 10-year experience

Is Intraoperative Parathyroid Hormone Monitoring Warranted in Cases of 4D-CT/Ultrasound Localized Single Adenomas?

Objective

To analyze the utility of intraoperative parathyroid hormone (IOPTH) monitoring for patients with primary hyperparathyroidism who had evidence of single-gland disease on preoperative imaging with modified 4-dimensional computed tomography that was done in conjunction with ultrasonography (Mod 4D-CT/US).

Study Design

Case series with chart review.

Setting

Tertiary care university medical center.

Subjects and Methods

Patients were drawn from consecutive directed parathyroidectomies performed between December 2001 and June 2013 by the senior authors. All patients had primary hyperparathyroidism and underwent a Mod 4D-CT/US study that showed findings on both studies that were consistent with a single adenoma. The modified Miami criteria were used for IOPTH monitoring (parathyroid hormone decrease by >50% and into the normal range).

Results

Of 356 patients who underwent parathyroid surgery, 206 had a single gland localized on the Mod 4D-CT and the US studies. IOPTH monitoring was used in 172 cases, of which 169 had adequate clinical follow-up to assess the surgical outcome. Twenty-one patients (12.4%) had IOPTH values that did not meet modified Miami criteria after removal of one gland, of which 7 were found to have multigland disease (4.1%). Three patients (1.8%) had persistent primary hyperparathyroidism despite an IOPTH that met modified Miami criteria.

Conclusions

Although IOPTH monitoring correctly identifies a small percentage of patients with multigland disease, some patients will be subjected to unnecessary neck explorations that can result in difficult intraoperative decisions, such as whether to remove normal or equivocal-sized glands when they are encountered.

Focused parathyroidectomy without intra-operative parathyroid hormone monitoring for primary hyperparathyroidism: results in a low-volume hospital

BACKGROUND

The role of routine intra-operative parathyroid hormone monitoring for sporadic primary hyperparathyroidism is contentious. Satisfactory results can be achieved in high-volume centres. The results of low-volume hospitals are rarely studied.

METHODS

A retrospective, non-comparative study was conducted. From November 2002 to October 2012, 105 patients with clinically sporadic primary hyperparathyroidism underwent focused parathyroidectomy without intra-operative parathyroid hormone monitoring. Single adenoma was localised on pre-operative ultrasonography or sestamibi scan. The cure rate, surgical complication rate and pathology findings were evaluated.

RESULTS

Most of the operations (63.8 per cent) were performed under local anaesthesia. All but two patients (98.1 per cent) were cured after surgery. There was only one case of double adenomas. No recurrent hyperparathyroidism was observed after a mean follow up of 56.9 months. Surgical complications comprised two cases (1.9 per cent) of transient vocal fold palsy and one case (1.0 per cent) of permanent vocal fold palsy. Seven patients (6.7 per cent) suffered temporary hypocalcaemia.

CONCLUSION

Satisfactory results of focused parathyroidectomy without routine intra-operative parathyroid hormone monitoring for appropriately selected primary hyperparathyroidism cases can be attained in a low-volume hospital.

Intraoperative parathyroid hormone level in parathyroidectomy: which patients benefit from it?

BACKGROUND

Intraoperative parathyroid hormone level (IOPTH) is withdrawn during parathyroidectomy to confirm the success of the procedure. Recently, the importance of IOPTH has been put to question. The purpose of this study is to determine whether IOPTH is necessary for all patients undergoing parathyroidectomy in the presence of frozen section.

MATERIALS AND METHODS

A cohort study of parathyroidectomies was performed in three university affiliated hospitals during 2007-2012. The patients were divided into two groups. Group 1: Patients with two preoperative concordant imaging localizing a hyperactive gland. Group 2: Patients without two concordant imaging. A comparison of benefit of IOPTH was carried out. Frozen section results were also analyzed to determine sensitivity and predictability of a parathyroid adenoma.

RESULTS

The study considered 221 patients having parathyroidectomies for primary hyperparathyroidism (PHPT). Of them, 10 were excluded due to incomplete data. Among the remaining, 186 had 2 concordant imaging preoperatively localizing an adenoma. 93.5% of whom were found intraoperatively in that location. IOPTH was not found to be of importance in 98.92% of the preoperative localized adenomas in the presence of frozen section. IOPTH added an estimate of 30.9 minutes on average to the surgery time.

CONCLUSION

This study demonstrates that the added operating time associated with IOPTH may not be justified for patients undergoing parathyroidectomy who have 2 concordant imaging preoperatively in the presence of frozen section. This study suggests a simple algorithm, The McGill Parathyroid Protocol (MPP), to help in approaching PHPT patients undergoing parathyroidectomy.

Clinical experience with modified Miccoli's endoscopic thyroidectomy for treatment of thyroid carcinoma in 86 cases

Background

The main purpose of this study was to assess the feasibility and relevant applying techniques of total thyroidectomy for thyroid carcinoma with a modified Miccoli’s approach.

Methods

Eighty-six patients with thyroid carcinoma consecutively received radical operation from October 2007 to June 2012. A cavity above the gland was constructed by a modified suspension method using the suspension retractor with suction catheter after the pathway making. Eighty-six cases underwent the modified Miccoli’s endoscopic thyroidectomy using the ultrasonic scalpel and the space maintain-regulating device. Level VI lymph node dissection was performed using the method of inspection pit.

Results

All the procedures were completed successfully. The average detection rate of level VI lymph nodes, the average time of thyroidectomy and lymph nodes dissection were 7.27 ± 3.99 pieces per case, 51.32 ± 13.35 min, and 38.43 ± 15.24 min, respectively. With regard to postoperative complications, there were three cases of delayed transient hoarseness, two patients with transient numbness of hands and feet, one subject with chylous fistula, and no hemorrhage.

Conclusion

Total thyroidectomy for thyroid carcinoma can be safely performed with the modified Miccoli’s approach by using ultrasonic scalpel and the space maintain-regulating device. Application of these adaptive reforms can obviously reduce the difficulties in manipulation and have the advantages of minimal incisions, good cosmetic results, less bleeding, shorter hospital stay, and fewer complications.

Open mini-incision parathyroidectomy for solitary parathyroid adenoma

Parathyroid surgery is the acceptable definitive treatment for primary hyperparathyroidism (pHPT) due to parathyroid adenoma. Open mini-incision parathyroidectomy (O-MIP) has an excellent cure rate and minimal morbidity. We aim to demonstrate the safety, efficacy and subjective patient satisfaction of O-MIP and investigate the accuracy of pre-operative radiological localisation in relation to operative findings. A retrospective review of patients who underwent O-MIP for pHPT due to solitary parathyroid adenoma from April 2006 to August 2012 was performed. All patients were initially investigated by an endocrinologist to confirm pHPT with pre-operative localisation imaging using ultrasound scan (USS) and 99mTc-sestamibi (MIBI). One hundred and fifty consecutive patients were included with a median age of 62 years. Pre-operative USS and MIBI scans were concordant in 71 % of cases. In combined modality (USS and MIBI), localisation was 94.8 % accurate. There was 95.5 % identification of parathyroid tissue confirmed by intra-operative frozen section. Ninety-one percent of patients were treated as a day case. The median operative time was 60 min. The mean pre-operative calcium level was 2.98 mmol/l, and the short-to-medium term mean calcium level was 2.49 (Paired t test, p < 0.001). There was no significant complication. O-MIP confers significant advantages over the traditional gold standard treatment of bilateral neck exploration. Accurate localisation is the key to successful O-MIP. In experienced hands, ultrasound and MIBI may be the only pre-operative investigations required for accurate localisation.

Gamma Probe Guided Minimally Invasive Parathyroidectomy without Quick Parathyroid Hormone Measurement in the Cases of Solitary Parathyroid Adenomas

OBJECTIVE

In this study, our aim was to study the efficiency of gamma probe guided minimally invasive parathyroidectomy (GP-MIP), conducted without the intra-operative quick parathyroid hormone (QPTH) measurement in the cases of solitary parathyroid adenomas (SPA) detected with USG and dual phase 99mTc-MIBI parathyroid scintigraphy (PS) in the preoperative period.

MATERIAL AND METHODS

This clinical study was performed in 31 SPA patients (27 female, 4 male; mean age 51±11years) between February 2006 and January 2009. All patients were operated within 30 days after the detection of the SPA with dual phase 99mTc-MIBI PS and USG. The GP-MIP was done 90-120 min after the iv injection of 740 MBq 99mTc-MIBI. In all cases, except 1 patient, the GP-MIP was performed under local anesthesia; due to the enormity of size of SPA, then general anesthesia is chosen.

RESULTS

The operation time was 30-60 min, mean 38,2±7 min. In the first postoperative day, there was a more than 50% decrease in PTH levels in all patients and all but one had normal serum calcium levels. Transient hypocalcemia was detected in one patient.

CONCLUSION

GP-MIP without intra-operative QPTH measurement is a suitable method in the surgical treatment of SPA detected by dual phase 99mTc-MIBI PS and USG.

CONFLICT OF INTEREST

None declared.

Sleeping parathyroid tumor: rapid hyperfunction after removal of the dominant tumor

CONTEXT

Due to frequent multiplicity of tumors in multiple endocrine neoplasia type 1, it may be difficult to decide when to stop a parathyroid exploration. A fall of intraoperative serum PTH by a certain percentage during parathyroid surgery is often used as one criterion for ending the operation.

RESULTS

We report two patients with primary hyperparathyroidism due to multiple endocrine neoplasia type 1 who had their first parathyroidectomy at the National Institutes of Health. In both cases, two and a half glands were removed, an extensive search was done for an occult parathyroid tumor, and intraoperative PTH decreased markedly to the lower limits of normal, suggesting a successful operation. Despite this, both patients became hypercalcemic within 3 d after the operation and showed persistent primary hyperparathyroidism. Detailed findings suggest the following course: chronic hypercalcemia had caused near total suppression of PTH secretion by an undiscovered parathyroid tumor (sleeping parathyroid tumor). When the hypercalcemia decreased after surgery due to the removal of the dominant parathyroid tumor(s), the abnormal yet previously suppressed tumor rapidly began to oversecrete PTH and thus caused postoperative hypercalcemia.

CONCLUSIONS

Even a fall of the intraoperative PTH to the lower limits of the normal range cannot guarantee that removal of all parathyroid tumors has been complete in cases with multiple tumors. These findings likely reflect strikingly differing PTH secretory functions among distinct tumors in the same patient, with hypercalcemia at least from a dominant tumor suppressing PTH secretion by one or more other parathyroid tumors.

Endoscopic parathyroidectomy in primary hyperparathyroidism

During the past decade, endoscopic video-assisted parathyroidectomy (EP) for primary hyper parathyroidism (PHPT) has gained wider acceptance. The endoscopic gasless procedure described by P. Miccoli (1997-1998) offers an attractive technique. A routine preoperative localization study was performed with both ultrasonography and 99m TC-Sestamibi scintigraphy for each patient with sporadic PHPT. The criteria to select patients eligible for EP included absence of significant nodular goiter, a previous neck surgery, a need for concomitant thyroidectomy, a significant obesity, and multiple enlarged parathyroid glands. The surgical outcome and the use of preoperative localization together with the operative strategy were evaluated. From 2005 to 2009, 59 out of 75 patients (78%) were potentially candidates for this approach. An enlarged parathyroid gland was located by both types of imaging for 34 patients (57%) and by 99 m Tc-Sestamibi scintigraphy for 46 patients (77%). Conversion was required in 11 cases (18%). Nine patients had a negative preoperative imaging study and five underwent a successful EP. The operating time ranged from 35 to 120 min (median 45 min). Usually patients were discharged home at 48 h. There were no cases of permanent hypocalcemia or recurrent laryngeal nerve palsy. Postoperative review showed that all calcium and parathyroid hormone levels remained normal at 3 months except for 1 patient with a double adenoma. EP is a quick, safe, and effective procedure in a selected group of patients. Our results show that this technique can be easily introduced into a general head and neck practice.