Parathyroid Surgery - Minimally invasive (focused) parathyroidectomy We receive many patient inquiries regarding minimally invasive parathyroidectomy (MIP). Conventional open (4-gland) parathyroid exploration was the considered the standard of care for treatment of primary hyperparathyroidism until the 1990s, when improvements in imaging techniques made limited (less than 4-gland) exploration feasible(1).

Now, many expert centers worldwide have adopted limited parathyroid exploration as their preferred surgical approach (2-4).

The underlying principle behind limited exploration is the fact that approximately 90% of individuals with primary hyperparathyroidism have only one diseased gland (5). The challenge is then to find the culprit gland successfully prior to operation. The essential imaging techniques used to localize solitary parathyroid adenomas are parathyroid sestamibi (a nuclear medicine test) and ultrasound.


	Minimally invasive parathyroid surgery can be accomplished through an incision measuring 1.5-2.0 cm in length. (1.5-2.0 cm = 1/2-3/4 inch) View Larger Image \| View Scar Gallery

	Same patient (above with penny) 3 months after surgery. Please mouse over the image to highlight scar. View Larger Image \| View Scar Gallery

	MIP begins with a 1.5-2.0 cm skin incision (1.5-2.0 cm = 1/2-3/4 inch). View Larger Image

	A parathyroid adenoma (yellow-tan colored) protrudes into the surgical field during exposure for minimally invasive parathyroid surgery. View Larger Image

In experienced hands, the sensitivity of each of these techniques approaches 90% (6, 7). Therefore, most people with primary hyperparathyroidism can be treated with MIP.

Definitions - Parathyroid Surgery

(See FAQ: What is the definition of minimally invasive parathyroidectomy?)

The movement toward MIP was initially driven by patients and market forces. Minimally invasive techniques, such as laparoscopy, were being used for abdominal operations, offering patients reduced pain and more rapid recovery. Similar approaches to endocrine surgery were seen as a logical extension of this. A number of novel techniques have been developed for limited parathyroid exploration:

Videoendoscopic – gas insufflation
Videoendoscopic – gasless
Video-assisted (MIVAP)
Radioguided/gamma probe (MIRP)
Focused central mini-incision (2.5 cm = 1 in)
Focused lateral mini-incision (1.5-2.0 cm = 0.6 to 0.8 in)

One significant problem affecting initial descriptions of these techniques was that many groups were calling their procedures “minimally invasive” without a clear definition of what exactly the term “minimally invasive” meant. In fact, this paucity of definitions remains a problem today, raising concern among some experts over the possibility that inflated claims are being used for the purpose of self-promotion (8).

The terminology problem was addressed in 2003 by Brunaud and associates from UC San Francisco, who systematically analyzed incision length for several types of endocrine operations. They recommended that the term “minimally invasive” only be applied to parathyroid procedures utilizing an incision length of less than 2.5 cm (1 in) (9).

Here at UCLA, we perform MIP using the focused lateral mini-incision technique
(see “Surgical Technique” below).

Anesthesia - Parathyroid Surgery

(See FAQ: What type of anesthesia is used and why?)

Anesthetic care is individualized to the patient, with almost all patients given their choice of either general anesthesia (going completely to sleep) or light sedation. Both methods are safe and comfortable, and no patients have experienced any recollection or awareness of the procedure afterwards. There have been no anesthesia-related complications over the past 1000+ operations.

In all cases, the area of the incision is pre-treated with a local anesthetic (numbing medicine similar to what you might receive at a dentist's office) that lasts approximately 6 hours. After surgery, our patients typically awaken with little or no pain, and the majority never require any pain medication after surgery. Our patients are routinely given anti-nausea medications during the operation to minimize nausea in the post-operative period.

Surgical Technique - Parathyroid Surgery

(See FAQ: Which surgical technique is used and why?)

Dr. Yeh has had direct, hands-on experience with almost all of the MIP techniques listed above. Research studies suggest that the various techniques all offer a similarly high success rate (>98%) and low complication rate (about 1%) when performed by experienced surgeons (2). At UCLA, we favor the focused lateral mini-incision technique first described by Delbridge and associates in 2002, which involves an incision length of 1.5-2.0 cm (about ¾ in) (10). In our opinion, this method provides the most direct access to the parathyroid glands, minimizes tissue injury, and has superior cosmetic results.

We do not routinely use intraoperative radio-guidance (gamma probe) or recurrent laryngeal nerve monitoring, as neither of these adjuncts has been proven to improve the results of parathyroid surgery (11, 12). In fact, most experts agree that both are unnecessary (8, 13). (See FAQ: Is the gamma probe used during parathyroid surgery? And: Is recurrent laryngeal nerve monitoring/EMG used during surgery?) Our high success rates, which are equivalent to those published by other high-volume specialty centers, are based on experience, accurate localization studies, thorough knowledge of the anatomy and embryology, and sound surgical technique.


View Larger Image	View Larger Image
The focused lateral mini-incision technique provides the most direct access to the parathyroid glands, as shown in these 3-D cutaways.

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Length of Operation - Parathyroid Surgery

The average operating time is 17 minutes, with 90% of operations being completed in less than 30 minutes. The shortest operation performed here thus far lasted 6 minutes, consistent with previously published reports using this technique (14). Though we value efficiency, we do not necessarily equate fast surgery with good surgery. Patient safety is our utmost priority. Ultimately, our operations take as long as necessary to complete in a safe and meticulous manner.

Surgeon-performed Ultrasound

Ultrasound revealing an enlarged, oval-shaped parathyroid adenoma.Color Doppler is used to detect small blood vessels leading to the adenoma.

High-resolution ultrasound of the neck is increasingly acknowledged to be the most sensitive anatomic imaging modality for the thyroid and parathyroids (15).

We agree with recently published reports highlighting the importance of surgeon-performed ultrasound in the management of parathyroid disease (16-18).

New patients undergo ultrasound examination during their first clinic visit. Just before surgery is commenced, ultrasound is again used to position the incision directly over the diseased gland.

Intra-operative Parathyroid Hormone (IOPTH) Monitoring

PTH levels are measured 4 times during surgery. Hormone levels typically fall into the normal range (blue dashed line) within 10 minutes of removing the abnormal gland. Calcium levels normalize within 12 hours in most cases.

We do use IOPTH monitoring as evidence of biochemical cure during MIP. We utilize the very latest rapid IOPTH assay platform, which returns results within 8 minutes. Four blood samples are drawn during the operation. Because parathyroid hormone is very short-lived in the bloodstream (half life about 3.5 minutes), hormone levels are observed to fall >50% or into the normal range within 10 minutes of removing the diseased parathyroid gland (19).

View PTH plot graph (PDF)

Duration of Hospitalization and Recovery Time
(See FAQ: Can surgery be done on a “day only” or “same day” basis?)

Most patients are observed for 4 hours before being discharged the same day, though the option to stay overnight is always available. Patients are able to return to normal light activities right away. We advise that strenuous activities, such as heavy lifting or sports, be avoided for 5 days after surgery. Most patients are physically able to return to work the day after surgery, though most choose to take a few days off to recover at their own pace.

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References

1. Sackett WR, Barraclough B, Reeve TS, Delbridge LW. Worldwide trends in the surgical treatment of primary hyperparathyroidism in the era of minimally invasive parathyroidectomy. Arch Surg. 2002;137(9):1055-9.

2. Lee JA, Inabnet WB, 3rd. The surgeon's armamentarium to the surgical treatment of primary hyperparathyroidism. J Surg Oncol. 2005;89(3):130-5.

3. Miccoli P, Berti P, Materazzi G, Donatini G. Minimally invasive video assisted parathyroidectomy (MIVAP). Eur J Surg Oncol. 2003;29(2):188-90.

4. Udelsman R. Six hundred fifty-six consecutive explorations for primary hyperparathyroidism. Ann Surg. 2002;235(5):665-70; discussion 670-2.

5. Sosa JA, Udelsman R. Minimally invasive parathyroidectomy. Surg Oncol. 2003;12(2):125-34.

6. Perrier ND, Ituarte PH, Morita E, et al. Parathyroid surgery: separating promise from reality. J Clin Endocrinol Metab. 2002;87(3):1024-9.

7. Yeh M, Barraclough BM, Sidhu SB, Sywak MS, Delbridge LW. 200 Consecutive parathyroid ultrasound studies by a single ultrasonologist. Endocrine Practice:in press.

8. Duh QY. Presidential Address: Minimally invasive endocrine surgery--standard of treatment or hype? Surgery . 2003;134(6):849-57.

9. Brunaud L, Zarnegar R, Wada N, Ituarte P, Clark OH, Duh QY.Incision length for standard thyroidectomy and parathyroidectomy: when is it minimally invasive? Arch Surg. 2003;138(10):1140-3.

10. Agarwal G, Barraclough BH, Reeve TS, Delbridge LW. Minimally invasive parathyroidectomy using the 'focused' lateral approach. II. Surgical technique. ANZ J Surg. 2002;72(2):147-51.

11. Beldi G, Kinsbergen T, Schlumpf R. Evaluation of intraoperative recurrent nerve monitoring in thyroid surgery. World J Surg. 2004;28(6):589-91.

12. Inabnet WB, 3rd, Kim CK, Haber RS, Lopchinsky RA. Radioguidance is not necessary during parathyroidectomy. Arch Surg. 2002;137(8):967-70.

13. Palazzo FF, Delbridge LW. Minimal-access/minimally invasive parathyroidectomy for primary hyperparathyroidism. Surg Clin North Am. 2004;84(3):717-34.

14. Agarwal G, Barraclough BH, Robinson BG, Reeve TS, Delbridge LW. Minimally invasive parathyroidectomy using the 'focused' lateral approach. I. Results of the first 100 consecutive cases. ANZ J Surg. 2002;72(2):100-4.

15. Senchenkov A, Staren ED. Ultrasound in head and neck surgery: thyroid, parathyroid, and cervical lymph nodes. Surg Clin North Am. 2004;84(4):973-1000, v.

16. Kell MR, Sweeney KJ, Moran CJ, Flanagan F, Kerin MJ, Gorey TF. Minimally invasive parathyroidectomy with operative ultrasound localization of the adenoma. Surg Endosc . 2004;18(7):1097-8.

17. Solorzano CC, Lee TM, Ramirez MC, Carneiro DM, Irvin GL.Surgeon-performed ultrasound improves localization of abnormal parathyroid glands. Am Surg. 2005;71(7):557-62; discussion 562-3.

18. Van Husen R, Kim LT. Accuracy of surgeon-performed ultrasound in parathyroid localization. World J Surg . 2004;28(11):1122-6.

19. Carneiro DM, Solorzano CC, Nader MC, Ramirez M, Irvin GL, 3rd.Comparison of intraoperative iPTH assay (QPTH) criteria in guiding parathyroidectomy: which criterion is the most accurate? Surgery. 2003;134(6):973-9; discussion 979-81.

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