Intraoperative Quick Parathyroid Hormone Assay Research Articles

Prospective evaluation of intra-operative quick parathyroid hormone assay as an early predictor of post thyroidectomy hypocalcaemia

BackgroundHypocalcaemia following total thyroidectomy is a major contributing factor in delayed hospital discharge and dissuading surgeons from day care thyroidectomy. We prospectively evaluated the utility of Intra-operative serum quick parathyroid hormone level measurement twenty minutes after total thyroidectomy in predicting post-operative hypocalcemia. Material and methodsProspective longitudinal study which included patients undergoing total thyroidectomy for benign or malignant thyroid disorders at SGPGIMS, Lucknow, India from November 2013 to February 2015. Patients who received calcium prophylaxis were excluded from the study. Intraoperative serum quick PTH level measurements were done twenty minutes after resection of thyroid. Serum calcium levels were estimated preoperatively and on three consecutive post operative days. Calcium supplementation was started in patients with symptomatic hypocalcemia. ResultsThe study included 100 patients with a mean age of 41 years, range 17–72 years. 48 patients had Euthyroid multinodular goitre, 10 patients grave's disease and 42 patients had differentiated thyroid cancer. Total thyroidectomy was performed in 88 patients, total thyroidectomy with lymph node dissection in 12 patients. Post-operatively 23% patients experienced symptomatic hypocalcemia. The IOPTH level of 9 pmol/L, twenty minutes after total thyroidectomy, had the highest sensitivity and specificity of 92% and 83% respectively in predicting post-operative hypocalcemia. ConclusionParathyroid hormone assay twenty minutes after thyroidectomy is an accurate and reliable means of predicting clinically relevant hypocalcemia. Patients with PTH values greater than 9 pmol/L twenty minutes after thyroidectomy, can be safely discharged on the same postoperative day as the probability of life threatening hypocalcemia is unlikely.

Intraoperative parathyroid hormone assay during surgery for secondary hyperparathyroidism: is it time to give up the chase at the hormone?

In the early 1990s, when George Irvin reported his firstresults about the use of a quick intraoperative parathyroidhormone assay (ioPTHa) during surgery for primaryhyperparathyroidism (PHPT), this innovative instrumentappeared to be an extremely promising way to providesurgeons with reliable guidance while performing a para-thyroidectomy for PHPT [1]. In fact, the method had anacceptable certainty of confirming in most patients that allof the hyperfunctioning parathyroid tissue in the neck hadbeen removed, to the extent of defining it as a ‘‘biochem-ical frozen section.’’ Some of the limits of the techniquebecame evident quite soon, because a limited but signifi-cant number of false-positive and false-negative resultsseemed to be unavoidable in every series that was reported,adding some uncertainty about the real effectiveness of thetool [2].The main problem was how to determine the cutoff forthe PTH drop rate and the timing of the blood sample to betested. The choice of these two data can heavily conditionthe balance between a false-positive and a false-negativeresult [3]. These limits can influence even more the out-comes in patients with secondary HPT (SHPT) and tertiaryHPT, where the cutoff seems to be more difficult todetermine, for several reasons [4–6].Correctly, Conzo et al. [7] quoted several proposedcutoff values in their report as a percentage of the initialvalue or as an absolute value. Also, the timing variedgreatly from series to series. The choice by these authors tochoose a 20-min cutoff seems reasonable. Even though thehalf-life of this hormone is limited to very few minutes, itsvalues at the beginning of the operation are much higherthan in PHPT, and because of the manipulation, whichinvolves all of the glands, last much longer. Thus, con-sidering a time consistently longer than 10 min shouldguarantee better results. For the same reason, it is moreimportant to establish a percentage of the PTH drop withrespect to the initial value rather than its absolute value. Infact, if all the parathyroid tissue were removed, PTHshould be, presumably, 0; but this never happens.Nevertheless, a really ‘‘total’’ parathyroidectomy ismandatory, and by then, the use of ioPTHa could signifi-cantly modify the surgical strategy. It is well known,indeed, that removal of four enlarged parathyroid glands isnot sufficient to consider the operation successful: a fifthand even a sixth gland can be present in these patients insignificantly higher percentages than in patients affected byPHPT [4], thus inducing the surgeon to continue the neckexploration. In these patients, an ablation of the upperhorns of the thymus on both sides would be highlyadvisable.However, even if the expected drop does not occur after20 min, this does not necessarily mean that cure has notbeen achieved, because the PTH level might decreasemuch later than 20 min after surgery. Because a supernu-merary gland might be in the mediastinum, an extensiveand time-consuming neck exploration is sometimesunreasonable. For similar reasons, most surgeons do notadvocate the use of sophisticated and costly preoperativeimaging studies, and in any event, these cannot substitutefor the experience of a surgeon with a high volume ofparathyroidectomies [8]. Despite these limits, the use ofioPTHa might help an experienced surgeon in tailoring hisor her operative strategy.The possible prognostic value of ioPTHa to predict apossible hypoparathyroidism after surgery, which comes

A Prospective Evaluation of Quick Intraoperative Parathyroid Hormone Assay at the Time of Skin Closure in Predicting Clinically Relevant Hypocalcemia after Thyroidectomy

BackgroundPost-thyroidectomy hypocalcemia is a major contributing factor in delayed hospital discharge and dissuading surgeons from ambulatory thyroidectomy. We prospectively evaluated the accuracy and reliability of quick parathyroid hormone level measurement at skin closure (PTH-SC) in predicting clinically relevant hypocalcemia (i.e., patients requiring calcium ± calcitriol supplements on hospital discharge).MethodsOf the 117 patients who underwent a total or completion total thyroidectomy and PTH-SC, 17 (14.5 %) had hypocalcemic symptoms or adjusted calcium <1.90 mmol/L requiring calcium and/or calcitriol supplements on discharge. Serum calcium was checked regularly in the perioperative period until stabilization and an additional quick PTH was checked on the following morning (PTH-D1). Univariate and multivariate analyses were performed to evaluate potential preoperative clinicopathologic factors and postoperative day 0 biochemical indicators. Youden’s index and the area under the ROC curve (AUC) were used to determine the best cutoff value and predictability of significant variables or criteria, respectively.ResultsIn the multivariate analysis, low preoperative adjusted calcium (p = 0.041) and low PTH-SC (p = 0.001) were the two independent variables associated with hypocalcemia. PTH-SC (≤1 or >1 pmol/L) had a higher specificity (95.0 %) and AUC (0.887) than serial calcium monitoring or PTH-D1 alone. Although 3/98 of patients with PTH-SC >1 pmol/L required calcium supplements on discharge, they required only the minimum amount to maintain normocalcemia.ConclusionPTH-SC is an accurate and reliable means of predicting clinically relevant hypocalcemia. It would be reasonable to discharge those with PTH-SC >1 pmol/L on the same operative day as the risk of life-threatening hypocalcemia would seem unlikely.

Is minimally invasive parathyroidectomy without QPTH monitoring justified?

It is matter of discussion if quick parathyroid hormone (QPTH) monitoring is helpful in patients with primary hyperparathyroidism (PHPT) and "localized single-gland disease" (SGD; concordant sestamibi and ultrasound results) to further increase the rate of success (permanent normocalcemia) of performing selective parathyroidectomy by minimally invasive parathyroid exploration (MIP). The aim of this study was to evaluate if a randomized controlled trial was justified in order to clarify this discussion. The prospective database of patients with sporadic PHPT, SGD, MIP, and QPTH monitoring (1999-2005) was evaluated regarding the "conversion rate" to bilateral exploration and permanent normocalcemia ("QPTH" group). Retrospectively, the patients were analyzed a second time "without" applying QPTH monitoring ("non-QPTH" group). Statistical differences between both groups were calculated (McNemar's test). By definition, 338 patients with "localized SGD" underwent MIP. MIP was finished in 308 (91.1%) patients. Five of 308 patients (1.6%) showed persisting (n = 1) or recurrent disease (n = 4). In 30 of 338 patients (8.9%), a conversion to bilateral exploration was necessary (false preoperative localization 15 patients--one patient not cured; multiple-gland disease correctly indicated by QPTH monitoring 15 patients--one patient not cured). Analyzing the "non-QPTH" group, 14 additional patients showed persisting disease. Thus, without using QPTH monitoring, the rate of persisting PHPT would increase from 0.9% (three patients) to 5.0% (17 patients; p = 0.0005). Intraoperative QPTH assay seems necessary even in patients with "localized SGD" by two techniques in an endemic goiter region. Abandoning QPTH monitoring would more than double the rate of persisting disease. A randomized trial seems not to be justified.

Thyroidectomy and parathyroid hormone: tracing hypocalcemia-prone patients

Background The aim of this prospective study was to identify patients at high risk of developing hypocalcemia after thyroidectomy on the basis of the parathyroid hormone (PTH) level on the first postoperative day. Methods We included 160 patients undergoing total thyroidectomy in a period of 6 months by the same surgical team in this study. In all patients the PTH level was measured before surgery on the day of surgery (PTH1), and on the first postoperative day (PTH2), whereas serum calcium level was measured daily until discharge. Patients were classified as hypocalcemic if they had a serum calcium level less than the normal range on the first postoperative day, independently of symptoms of hypocalcemia. Results At an average follow-up period of 5.9 months (range, 4–9 mo), 66 patients were considered hypocalcemic, 57 patients (35.6%) had a transient hypocalcemia, and 9 patients (5.6%) required calcium–vitamin D supplementation for persistent hypocalcemia. The mean PTH1 value was 54.4 ± 17.2 pg/mL (median, 53.85 pg/mL), the mean PTH2 value was 22.8 ± 13.3 pg/mL (median, 21 pg/mL). The mean PTH decrease in value was 51.54% ± 27.4% (median, 51.83%; range, 4%–94%) and 43.7% of patients presented a PTH decrease of more than 50%. The presence of a postoperative hypocalcemia was statistical correlated both with the PTH2 level and with the PTH drop percent value ( P < .001 and P = .002, respectively). With the use of the receiver operating characteristic curve, the maximum sum of the sensitivity and specificity for the correlation of PTH2 levels and hypocalcemia occurred at a PTH2 level of 9.6 pg/mL. Conclusions The PTH measurement on the first postoperative day may be considered a useful method to predict postthyroidectomy hypocalcemia, thus avoiding prolonged hospitalization. Moreover, PTH dosage at first postoperative day is more reliable and less expensive than intraoperative quick PTH assay.

Is Intraoperative Parathyroid Hormone Assay Mandatory for the Success of Targeted Parathyroidectomy?

Minimally invasive parathyroidectomy has become the first surgical option for patients with primary hyperparathyroidism (HPT) in many places. Preoperative localization studies are mandatory, and the use of a quick parathyroid hormone (PTH) assay is highly recommended. The aim of this study was to analyze our initial series of targeted parathyroidectomies. In a 2-year period, 50 patients underwent unilateral neck exploration for HPT under local anesthesia and light sedation. After biochemical diagnosis, a technetium 99m sestamibi scan was performed on all patients, and cervical ultrasonography was obtained in some patients. Frozen section analysis was used to confirm parathyroid tissue in all patients. There was no biochemical intraoperative evaluation of PTH. Demographics, surgical details, results, and complications were analyzed. There were 35 women and 15 men, with a mean age of 56 years (range 23 to 85 years). Mean preoperative calcium was 11.4 mg/dL (range 10.0 to 14.8 mg/dL), and PTH was 342 pg/mL (range 105 to 2,231 pg/mL). Mean surgical time was 52 minutes (range 30 to 100 minutes), and mean hospital stay was 2 days (range 1 to 7 days). Mean parathyroid weight was 1,000 mg (range 117 to 17,000 mg). Sestamibi scan correctly localized the abnormal gland in 47 patients (94%). There was one postoperative complication (bleeding); two patients required contralateral exploration, and persistent hypercalcemia developed in one that required surgical reintervention. After a mean followup of 12 months (range 3 to 25 months), all patients were normocalcemic. Targeted parathyroidectomy is safe and effective. Despite the fact that quick intraoperative PTH assay was not used, the cure rate was 98%.

Surgeon-Performed Ultrasonography as the Initial and Only Localizing Study in Sporadic Primary Hyperparathyroidism

With a secure diagnosis of hyperparathyroidism, preoperative localization of abnormal glands is the initial step toward limited parathyroidectomy. Nuclear scanning and ultrasonography done by third parties are costly. We investigated whether ultrasonography performed by the operating surgeon (SUS) could be the initial and only preoperative localization study in patients with sporadic primary hyperparathyroidism. Two hundred twenty-six patients underwent preoperative SUS and Sestamibi scans before limited parathyroidectomy guided by quick intraoperative parathyroid hormone assay. SUS findings were noted before the surgeon had access to the scan results. Charge for localization by nuclear scan was 1,315 dollars and 204 dollars for SUS. Successful localization was determined by operative findings, intraoperative hormone dynamics, and postoperative calcium levels. SUS correctly localized all the offending glands in 173 of 226 (77%) successfully treated patients. In 53 patients, SUS showed no parathyroid gland (n = 32), did not recognize multiglandular disease (n = 5), and showed an incorrect location of the abnormal gland (n = 16). In these patients, the technetium-99m-sestamibi scans successfully identified all abnormal tissue in 30 of 53 (57%). Localization using both methods was correct in 203 of 226 (90%) patients. Accuracy of SUS and scans used separately was equal. With use of quick intraoperative parathyroid hormone assay, successful parathyroidectomy was accomplished in 223 of 226 (99%), unilateral exploration in 88%, and overnight stay avoided in 78% of patients. With equal accuracy, SUS is more convenient, less expensive, and noninvasive when compared with scans. Sestamibi should be used when the SUS is negative or equivocal. SUS should be the initial localizing test in the treatment of sporadic primary hyperparathyroidism.

The Value of Intraoperative Quick Parathyroid Hormone Assay in Patients with Renal Hyperparathyroidism

The Value of Intraoperative Quick Parathyroid Hormone Assay in Patients with Renal Hyperparathyroidism

Quick Intraoperative Parathyroid Hormone Assay: Surgical Adjunct to Allow Limited Parathyroidectomy, Improve Success Rate, and Predict Outcome

Intraoperative parathyroid hormone (PTH) assay (QPTH) has made possible less invasive operative approaches in the treatment of primary hyperparathyroidism with stated advantages. When compared to the traditional bilateral neck exploration (BNE), only the targeted, hypersecreting gland is excised, leaving in situ non-visualized but normally functioning parathyroids. The QPTH-guided limited parathyroidectomy (LPX) must be able to identify multiglandular disease (MGD), predict a successful outcome, and have a low recurrence rate. In our series, 421 patients who underwent LPX were compared to 340 undergoing BNE; all operative failures and patients followed for 6 months or longer were included. Operative failure occurred if serum calcium and PTH levels were elevated within 6 months of parathyroidectomy. Multiglandular disease was defined in the LPX group as more than one gland excision guided by QPTH or operative failure after removal of a single abnormal gland; in the BNE group it was defined as excision of more than one enlarged gland. Recurrence was defined as elevated calcium and PTH after 6 months of eucalcemia. Operative failure and MGD rates were compared using chi-squared analysis. The method of Kaplan-Meier and the log-rank test were used to compare recurrence rates. Operative success was seen in 97% of LPX patients and in 94% of the BNE group ( p = 0.02). Multiglandular disease was identified in 3% of LPX patients and 10% of BNE patients ( p < 0.001). There was no statistical difference in the overall recurrence rates ( p = 0.23). The QPTH-guided parathyroidectomy identifies MGD and allows an improved success rate with the same low recurrence rate when compared to the results of BNE.

Failure of Technetium Tc 99m Sestamibi Scanning to Detect Abnormal Parathyroid Tissue in a Horse and a Mule with Primary Hyperparathyroidism

Failure of Technetium Tc 99m Sestamibi Scanning to Detect Abnormal Parathyroid Tissue in a Horse and a Mule with Primary Hyperparathyroidism

Three new tools for parathyroid surgery: expensive and unnecessary?

The intraoperative quick parathyroid hormone assay, the intraoperative gamma probe, and endoscopic parathyroidectomy are three very new techniques developed to facilitate parathyroid surgery. Some hospitals do not have the necessary equipment, and many, like ours, continue to operate in the time-honored way. We performed a retrospective chart review of 34 such operations, done with the use of Sestamibi scans, but entirely without the newer modalities. Four-gland exploration was carried out on all patients. Operative times ranged from 15 to 165 minutes, with a mean of 47 minutes, and incision lengths ranged from 2 to 3 cm, with a mean of 2.8 cm. There was no mortality, no reoperation, and no vocal cord or recurrent laryngeal nerve injury. Our cure rate was 100%, as determined by a fall in postoperative calcium and parathormone levels. In our view, the intraoperative parathyroid hormone assay, gamma probe, and endoscopic parathyroidectomy add an entirely unnecessary cost to an operation that can be completed satisfactorily with a preoperative Sestamibi scan and a thorough four-gland exploration.

Section 1. Parathyroid: Intraoperative quick parathyroid hormone assay in the surgical management of hyperparathyroidism

Intraoperative quick parathyroid hormone (QPTH) assay is claimed to prevent failure during parathyroidectomy for hyperparathyroidism. The causes of operative failure have included multiglandular disease, ectopic parathyroid glands, supernumerary parathyroid glands, errors in frozen section evaluations, and missed diagnosis. A QPTH assay has been recognized as a useful method of determining whether hyperfunctioning tissues have been completely excised. However, an intraoperative QPTH assay may fail to detect the presence of double parathyroid adenomas. Use of this assay in conjunction with preoperative and intraoperative localization studies has led to the advocacy of more directed cervical procedures, such as limited, video-assisted, and endoscopic parathyroidectomy.

A quick intraoperative parathyroid hormone assay in the surgical management of patients with primary hyperparathyroidism: a study of 206 consecutive cases.

The traditional surgical approach for patients with primary hyperparathyroidism (PHPT) consists of the identification of at least four glands and in the removal of all hyperfunctioning parathyroid tissue. To evaluate whether intraoperative parathyroid hormone (PTH) monitoring will allow a more limited surgical procedure by confirming complete removal of all hyperfunctioning tissue. Plasma samples were obtained from 206 consecutive patients with sporadic PHPT before skin incision, during manipulation of a suspected adenoma, and 5 min (T-5) and 10 min after removal of abnormal parathyroid tissue. PTH was measured by a quick immunochemiluminescent assay (QPTH). The operative success was defined by a decrease of PTH greater than 50% of the highest pre-excision value. A >50% decrease of PTH occurred in 203 patients and was evident at T-5 in the majority of cases. All but three had normal serum calcium the day after surgery and afterwards. PTH concentration did not show a >50% decrease in the remaining three cases after completion of surgery. One patients had negative neck exploration and remained hypercalcemic; the other two had normal serum calcium at follow-up. Thus, the intraoperative QPTH correctly predicted the outcome of surgery in 201 patients (97.5%) (200 true positive and 1 true negative), and provided three false positive and two false negative results. The intraoperative QPTH measurement represents a useful tool to assist the surgeon during parathyroidectomy. It indicates whether all hyperfunctioning parathyroid tissue has been removed, limiting the procedure to a unilateral neck exploration in most cases.

Advantages of combined technetium-99m-sestamibi scintigraphy and high-resolution ultrasonography in parathyroid localization: comparative study in 91 patients with primary hyperparathyroidism

To evaluate the usefulness of the combination of Tc-sestamibi/Tc-pertechnetate subtraction scintigraphy (SS) and high-resolution neck ultrasonography (US) in patients with primary hyperparathyroidism (pHPT) undergoing parathyroidectomy. Ninety-one patients with proved pHPT were studied, excluding patients with persistent or recurrent disease. There were 65 (71.4%) women and 26 (28.6%) men, with a median age of 59 years (range 18-78 years). All patients underwent both SS and US prior to surgery, and the results were compared with operative and histological findings. The intraoperative quick-parathyroid hormone assay was available for 52 (57.1%) patients. When multiglandular disease was found, both SS and US were considered truly positive only when at least two enlarged parathyroid (PT) glands had been localized. Eighty-three (91.2%) solitary PT adenomas and three (3.3%) carcinomas were found. Moreover, two (2.2%) patients had a double adenoma and three (3.3%) patients had diffuse PT hyperplasia. The overall sensitivity of combined SS+US was 94.5% (86.8% and 80.4% for SS and US respectively). There was a significant (P<0.05, Student's t-test) difference in size between the PT glands correctly identified and undetected by SS, whereas the site of the removed PT tumors significantly (P<0.05, Fisher exact test) influenced only the US sensitivity. When the preoperative localization of the PT glands is chosen, the combination of SS and US represents a reliable noninvasive localization technique and should be considered for use in each patient with pHPT undergoing surgery.

The validity of quick intraoperative parathyroid hormone assay: an evaluation in seventy-two patients based on gross morphologic criteria.

Parathyroidectomy for primary hyperparathyroidism has conventionally required identification of all parathyroid glands with excision of grossly abnormal glands. Using this approach, cure rates exceed 95%. Directed cervical exploration has been advocated using quick intraoperative parathyroid hormone (QPTH) assay with preoperative localization. Adoption of this approach requires validation of the accuracy of QPTH assay. Patients with primary hyperparathyroidism undergoing bilateral neck exploration during a 31-month period were reviewed. Uniglandular (UGD) or multiglandular (MGD) disease was determined by gross morphologic criteria. QPTH assays were performed before skin incision and at 5, 10, and 20 minutes after excision of each abnormal gland. A 10-minute QPTH decrease of 50% from baseline levels indicated curative excision. These data were not used to guide extent of exploration or tissue resection. Of 72 patients, 55 (76%) had UGD and 17 (24%) had MGD. QPTH assay accurately predicted the disease state in 89%. Four (7%) UGD patients did not have an appropriate QPTH decline at 10 minutes. Four (24%) MGD patients had an inappropriate QPTH decline at 10 minutes. Using QPTH guided exploration, 6% (4 of 72) of patients would undergo unnecessary extended exploration and 6% (4 of 72) (95% CI, 1% to 13%) may require reoperation for unidentified MGD. These results validate the accuracy of QPTH assay.

The evolution of parathyroidectomy failures

Reported operative failure rates for primary hyperparathyroidism range from 5% to 10%. Failure has been due to multiglandular disease, ectopic parathyroid glands, errors in frozen section, and missed diagnoses. Recently, our operative approach has changed from bilateral cervical exploration to direction by preoperative localization and intraoperative quick parathyroid hormone assay. The purpose of this study is to examine the causes and rates of failure in this evolving approach to parathyroidectomy. Among 447 consecutive cases of primary hyperparathyroidectomy, 20 operative failures were examined. Three different operative approaches were compared with respect to causes and rates of failure. From 1969 to 1989, with bilateral neck exploration, failure was due to missed diagnoses, ectopic glands, multiglandular disease, and unknown causes, with a failure rate of 5%. From 1990 to 1993, with bilateral neck exploration and quick parathyroid hormone assay, failure was due to ectopic mediastinal glands, misinterpretation of frozen section, and operative judgment, with a failure rate of 10%. From 1993 to 1998, with preoperative localization and quick parathyroid hormone assay, the two operative failures (1.5%) were due to operative judgment and misinterpretation of the quick parathyroid hormone assay. The new surgical approach combining preoperative localization studies and intraoperative parathyroid hormone monitoring has eliminated the most common causes of parathyroidectomy failure and has significantly decreased the operative failure rate.

The evolution of parathyroidectomy failures

Background: Reported operative failure rates for primary hyperparathyroidism range from 5% to 10%. Failure has been due to multiglandular disease, ectopic parathyroid glands, errors in frozen section, and missed diagnoses. Recently, our operative approach has changed from bilateral cervical exploration to direction by preoperative localization and intraoperative quick parathyroid hormone assay. The purpose of this study is to examine the causes and rates of failure in this evolving approach to parathyroidectomy. Methods: Among 447 consecutive cases of primary hyperparathyroidectomy, 20 operative failures were examined. Three different operative approaches were compared with respect to causes and rates of failure. Results: From 1969 to 1989, with bilateral neck exploration, failure was due to missed diagnoses, ectopic glands, multiglandular disease, and unknown causes, with a failure rate of 5%. From 1990 to 1993, with bilateral neck exploration and quick parathyroid hormone assay, failure was due to ectopic mediastinal glands, misinterpretation of frozen section, and operative judgment, with a failure rate of 10%. From 1993 to 1998, with preoperative localization and quick parathyroid hormone assay, the two operative failures (1.5%) were due to operative judgment and misinterpretation of the quick parathyroid hormone assay. Conclusions: The new surgical approach combining preoperative localization studies and intraoperative parathyroid hormone monitoring has eliminated the most common causes of parathyroidectomy failure and has significantly decreased the operative failure rate. (Surgery 1999;126:998-1003.)

Minimally invasive open parathyroidectomy — A review

Background: Although bilateral neck exporation is the standard procedure in biochemically proven primary hyperparathyroidism a unilateral approach was developed to reduce surgical trauma, morbidity and duration of operation. The improvement of preoperative localisation methods and the introduction of a quick parathyroid hormone (QPTH) assay have helped to establish minimally invasive techniques. Methods: Reviewing literature, the clinical value of minimally invasive open parathyroidectomy (MIP; localized single gland disease, lateral approach through a 15–20 mm incision, selected exstirpation of the parathyroid tumor, documentation of the surgical success using QPTH assay) was analyzed and compared with endoscopic procedures. Results: Reviewing literature, eight authors describe 436 patients witReviewing literature, eight authors describe 436 patients with MIP. MIP was successfully performed in 401 out of 436 patients (92 %). A conversion to standard bilateral exploration was performed in 29 patients. Causes for conversion were false positive localisation in 12 (41 %), multiple gland disease in seven (24 %), double adenoma in four (14 %), difficult dissection in four (14%), concomitant thyroid disease in one and scars during reoperation in another. Complications are documented in three patients (0.7 %; paralysis of recurrent laryngeal nerve: two; rupture of a cystic parathyroid adenoma: one). Conclusions: Because of good functioning and excellent cosmetic results MIP is a cost-effective alternative to endoscopic procedures in localised single gland disease. Using a paramedian miniincision, the recurrent laryngeal nerve can be visualized and concomitant ipsilateral thyroid pathology can be treated. MIP is also feasible in reoperations. Intraoperative QPTH assay is mandatory.