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Parathyroidectomy
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47
Fig. 2 (a) Initial
dissection for bilateral
neck exploration. A
central, transverse cervical
incision lies 2cm above
the sternal notch. (b) The
skin is retracted and the
strap muscles are divided
at the midline
a
b
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J. L. McMullin and H. Chen
thyroid. The elements of the carotid sheath are then retracted laterally away from
the thyroid. A critical maneuver in parathyroid exploration is exposure and palpation of the prevertebral space that lies posterior to the esophagus.
Normal parathyroid glands are yellow-tan in color. They are typically 5mm in
diameter, attened or discoid in shape, and weigh between 30 and 50mg. They are
generally housed in a thin fatty envelope, giving them a classic “fried egg” appearance. Open exploration begins with interrogation of the superior parathyroid territory. Because of their shorter path of embryologic migration, the superior
parathyroids are more consistent in their location than the inferior parathyroids,
with the majority located within a 1.5cm radius of the tubercle of Zuckerkandl, a
postero-lateral prominence of the thyroid gland. Other important nearby structures
include the terminus of the recurrent laryngeal nerve, arborization of the inferior
thyroid artery, and the cricoid cartilage (Fig.3).
As superior parathyroid adenomas enlarge, they often slide inferiorly along the
paraesophageal space. By denition, the superior parathyroids are located posterolaterally to the plane of the recurrent laryngeal nerve (Fig.4).
Though routine identication of the recurrent laryngeal nerve is not considered
mandatory during parathyroid exploration, the surgeon must be extremely wary of
avoiding nerve injury while operating near the superior parathyroids. A small fraction of parathyroid glands lie partially or completely embedded in the thyroid gland
parenchyma; these may be either superior or inferior parathyroids.
The inferior parathyroid glands are located anteromedially to the plane of the
recurrent laryngeal nerve (Fig.4). The territory of the inferior parathyroid is relatively large, ranging from the superior pole of the thyroid to the anterior mediastinum. The majority of inferior parathyroid glands lie on the surface of the inferior
Fig. 3 Relationship of
structures surrounding the
superior parathyroid gland
during a bilateral neck
exploration. The superior
parathyroid adenoma abuts
the thyroid’s tubercle of
Zuckerkandl. The recurrent
laryngeal nerve (RLN) can
be seen traversing
anterior-medially to the
gland
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Fig. 4 Relationship of the
recurrent laryngeal nerve
(RLN) to the parathyroid
glands during bilateral
neck exploration for renal
hyperparathyroidism. The
thyroid gland has been
retracted medially toward
the patient’s left
49
pole of the thyroid, often near the inferior pole veins that demarcate the top of the
thyrothymic tract. Inferior parathyroid adenomas can frequently be found by following the thyrothymic tract down into the chest. Ectopic inferior parathyroids are
most commonly located in the thymus, and can almost always be removed
transcervically.
If three glands appear normal and one gland is enlarged, the diagnosis is a single
parathyroid adenoma. The safest method of dissecting out a parathyroid adenoma is
to start away from the vascular pedicle, mobilizing the lateral and inferior aspects
while avoiding violation of the gland capsule. The vascular pedicle is isolated last
and ligated. After irrigation and hemostasis, the strap muscles and platysma are
reapproximated. The skin is then closed in a subcuticular fashion.
If a four-gland exploration reveals hyperplasia (four enlarged glands), a subtotal
parathyroidectomy is generally performed. This involves complete removal of the
three most abnormal-appearing glands and partial resection of the fourth gland,
leaving 40–50mg of normal appearing tissue on an intact vascular pedicle. The
partial resection of the remnant should be performed before dissecting out the other
glands in case it becomes devascularized, and another remnant needs to be left
behind instead.
4.2 Unilateral andSelective/Targeted Exploration
Unilateral exploration involves an exploration of one side of the neck with identication of an ipsilateral normal gland to rule out four gland hyperplasia, whereas a
selective or targeted exploration uses an image-guided approach, typically with a
small incision measuring 2.5cm or less, and removal of a single parathyroid adenoma without identication of the ipsilateral normal gland. Frequently, intraoperative parathyroid hormone (IOPTH) monitoring is used to conrm completeness of
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J. L. McMullin and H. Chen
resection and other adjuncts such as intraoperative gamma probes can be utilized. A
unilateral exploration occurs in a similar manner to the bilateral neck exploration
and is typically performed through a central incision. Preoperative imaging typically identies a single adenoma and after excision of the adenoma, the ipsilateral
parathyroid is examined to determine if there is suspicion of hypercellularity. A
selective exploration can be performed through a central incision or a lateral incision and typically the incision is 2.0–2.5cm. With a lateral mini-incision approach,
the incision is placed directly over the parathyroid adenoma using ultrasound guidance, and provides the most direct exposure of the parathyroid-bearing regions. The
incision site is placed directly over the parathyroid adenoma using ultrasound guidance. Alternatively, placement of the incision approximately 5mm inferior to the
cricoid cartilage will typically offer adequate exposure. A 2cm transverse incision
is placed along a skin crease, centered over the anterior border of the sternocleidomastoid muscle. Small subplatysmal aps are created. The sternocleidomastoid
muscle is retracted laterally and the strap muscles are retracted medially. The thyroid is rotated anteriomedially and the carotid sheath elements retracted laterally.
After identication of the abnormal gland, dissection proceeds as in open exploration. At the surgeon’s preference, exploration of the territory of the non-excised
ipsilateral gland can be undertaken at this point to evaluate for multiple gland
disease.
4.3 IOPTH Monitoring
IOPTH monitoring is used to conrm complete removal of hyperfunctioning parathyroid tissue during limited exploration. Fall of the 10 min post-excision PTH
value to less than 50% of the highest pre-excision value is highly predictive of long-
term cure [6]. This can be used in both single parathyroid adenoma’s and multigland
disease [7]. Failure to meet this criterion may prompt the surgeon to convert to
bilateral neck exploration.
4.4 Radioguided Parathyroid Surgery
The technique of radioguided parathyroid surgery involves the preoperative intravenous injection of
counts from parathyroid glands utilizing an intraoperative gamma probe. A 10mCI
dose of
99m
prior to surgery. Intraoperatively, the gamma probe is used to measure a background
count from the thyroid isthmus. Once the abnormal parathyroid gland(s) are
resected, the specimen is placed on top of the gamma probe to obtain an “ex-vivo
count”, and a count greater than or equal to 20% of the background is consistent
99m
Tc-sestamibi and intraoperative measurements of radioactive
Tc-sestamibi is injected intravenously in the preoperative area 30min
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Fig. 5 Radioguided parathyroidectomy specimen with the ex-vivo count being read with the
gamma probe (left). The image on the right demonstrates the 20% rule with 471 as the background
count and anything greater than or equal to 20% of the background count is conrmatory of abnormal parathyroid tissue. Adenomas generally have much higher counts than hyperplastic parathyroid glands such as in this specimen that is 200% the background count
51
with abnormal parathyroid tissue. Typically single parathyroid adenoma’s have
background counts that are signicantly higher than hyperplastic parathyroid tissue
(>200% of the background count) [8] (Fig.5).
4.5 Is Four-Gland Exploration or Limited
Exploration Preferred?
The relative merits of four-gland exploration and limited exploration have been
debated for many years and both come with their own advantages and disadvantages
without clear evidence for superiority of one technique over the other [9]. Fourgland exploration allows for identication of all parathyroid glands, may lead to
discovery of occult multigland disease, and permits conclusion of the case without
IOPTH monitoring. Its disadvantages include increased operative time, placing two
recurrent laryngeal nerves at risk, and the theoretical risk of permanent hypoparathyroidism. Unilateral or selective/targeted exploration is generally faster and
involves fewer risks; however, it generally requires waiting for an IOPTH result and
may, in the opinion of some authors, lead to a slightly higher rate of operative failure
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J. L. McMullin and H. Chen
from missed multiple gland disease. The most reliable predictor of successful parathyroid surgery is surgeon experience and surgeons who perform parathyroid surgery should be comfortable with both techniques and be able to adapt to each
individual case [10]. In thinking of educating the next generation of surgeons, it is
important for both techniques to be taught to trainees [11].
5 Post-Operative Care
Parathyroid surgery is now typically performed as an outpatient procedure with
same-day discharge in appropriately selected patients. Postoperative complications
following parathyroidectomy are uncommon and symptoms of postoperative hypocalcemia can be prophylactically treated with oral calcium supplementation. Sameday discharge has been shown to be safe in both selective and bilateral neck
explorations without differences in complications [12]. Hematoma occurs in
approximately 0.1% of patients, and requires emergent reexploration. Post-operative
hypocalcemia may occur due to either iatrogenic hypoparathyroidism after four
gland manipulation or, more commonly, high-turnover bone disease and suppression of remaining parathyroid tissue in patients with biochemically severe disease.
Symptoms should be assessed and treated with supplemental calcium as needed.
Permanent hypoparathyroidism is only a risk for patients undergoing bilateral neck
exploration and should occur in <1% of patients. The rate of permanent recurrent
laryngeal nerve paresis is 1% or less in expert hands. The most common complication of parathyroid exploration is operative failure (persistent hyperparathyroidism),
dened as hypercalcemia occurring within 6months of operation. These patients
require reoperation. The overall frequency of operative failure ranges from 2% in
expert centers to 20% or more in low-volume centers [13].
References
1. Bilezikian JP, Khan AA, Silverberg SJ, Fuleihan GE, Marcocci C, Minisola S, etal. Evaluation
and management of primary hyperparathyroidism: summary statement and guidelines from
the fth international workshop. J Bone Miner Res. 2022;37(11):2293–314.
2. Wilhelm SM, Wang TS, Ruan DT, Lee JA, Asa SL, Duh QY, etal. The American Association
of Endocrine Surgeons guidelines for denitive management of primary hyperparathyroidism.
JAMA Surg. 2016;151(10):959–68.
3. Fazendin JM, Lindeman B, Chen H.Preoperative parathyroid localization does not improve surgical outcomes for patients with primary hyperparathyroidism. Am J Surg. 2020;220(3):533–5.
4. Cheung K, Wang TS, Farrokhyar F, Roman SA, Sosa JA. A meta-analysis of preoperative
localization techniques for patients with primary hyperparathyroidism. Ann Surg Oncol.
2012;19(2):577–83.
5. Kuo LE, Bird SH, Lubitz CC, Pandian TK, Parangi S, Stephen AE.Four-dimensional computed tomography (4D-CT) for preoperative parathyroid localization: a good study but are we
using it? Am J Surg. 2022;223(4):694–8.
Parathyroidectomy
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6. Mak N, Li J, Vasilyeva E, Hiebert J, Guo M, Lustig D, etal. Intraoperative parathyroid hormone measurement during parathyroidectomy for treatment of primary hyperparathyroidism:
when should you end the operation? Am J Surg. 2020;219(5):785–9.
7. Cayo AK, Sippel RS, Schaefer S, Chen H.Utility of intraoperative PTH for primary hyperparathyroidism due to multigland disease. Ann Surg Oncol. 2009;16(12):3450–4.
8. Ramonell KM, Fazendin J, Lindeman B, Chen H.My surgical practice: radioguided parathyroid surgery, how and why we use it. Am J Surg. 2022;223(1):203–5.
9. Ahmadieh H, Kreidieh O, Akl EA, El-Hajj FG.Minimally invasive parathyroidectomy guided
by intraoperative parathyroid hormone monitoring (IOPTH) and preoperative imaging versus
bilateral neck exploration for primary hyperparathyroidism in adults. Cochrane Database Syst
Rev. 2020;10(10):CD010787.
10. Chen H.Surgery for primary hyperparathyroidism: what is the best approach? Ann Surg.
2002;236(5):552–3.
11. Wang TS, Pasieka JL, Carty SE. Techniques of parathyroid exploration at North American
endocrine surgery fellowship programs: what the next generation is being taught. Am J Surg.
2014;207(4):527–32.
12. Kiernan CM, Schlegel C, Isom C, Kavalukas S, Peters MF, Solórzano CC.Ambulatory bilateral
neck exploration for primary hyperparathyroidism: is it safe? Am J Surg. 2016;212(4):722–7.
13. Schneider DF, Mazeh H, Chen H, Sippel RS.Predictors of recurrence in primary hyperparathyroidism: an analysis of 1386 cases. Ann Surg. 2014;259(3):563–8.
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Open Adrenalectomy
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AlexanderPapachristos andStanleyB.Sidhu
1 Indications
The three predominant indications for an open approach are:
• Primary adrenal malignancy
• Large tumor size or evidence of local invasion
• Conversion from a laparoscopic approach
Despite the evolution and increasing application of minimally invasive techniques,
the utilization of the open approach to adrenalectomy has remained relatively stable
over the last 15years, and represents approximately 15% of adrenalectomies in our
practice at a tertiary referral center, predominantly for primary and secondary adrenal malignancy, phaeochromocytoma, and large benign tumors >10–12cm [1].
Adrenocortical carcinoma (ACC) is an aggressive tumor that is often advanced
at presentation. In cases of non-metastatic disease, the major determinant of longterm survival is adequate surgical resection, respecting the oncologic principles of
complete resection without violation of the tumor capsule. Therefore, it is imperative that these patients are managed in high-volume centers by experienced surgeons. Even in experienced hands, the rates of R1 resection, intraoperative tumor
spillage, time to tumor bed or peritoneal recurrence and overall survival are signicantly worse for a laparoscopic compared to an open approach [2]. In our experience, avoiding capsular breach during manipulation of a large tumor is challenging
when attempted laparoscopically, especially when elevating it from the adrenal bed,
A. Papachristos (*) · S. B. Sidhu
Endocrine Surgical Unit, Royal North Shore Hospital, St Leonards, NSW, Australia
Northern Clinical School, Faculty of Medicine and Health, University of Sydney,
Sydney, NSW, Australia
e-mail: alex.papachristos@sydney.edu.au; stansidhu@nebsc.com.au
Switzerland AG 2024
H. Chen, B. Lindeman (eds.), Illustrative Handbook of General Surgery,
https://doi.org/10.1007/978-3-031-63878-7_7
55© The Author(s), under exclusive license to Springer Nature
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or achieving the necessary retraction to dissect major vascular structures from the
tumor. For this reason, we opt for an open approach in the management of ACC, in
concordance with current guidelines [3].
The multidisciplinary work-up of an adrenal lesion prior to surgery is of paramount importance. With appropriate use of high resolution CT-scan and PET scans,
potential intraoperative challenges can be anticipated. For example, the need for
en-bloc resection of adjacent organs or vasculature is predictable base on imaging,
and hence should be planned for, rather than coming as a surprise intraoperatively
[4]. If local invasion or vascular involvement is suspected, contrast-enhanced MRI
is the preferred imaging modality to conrm the diagnosis [5]. In our experience,
the need for unexpected conversion to open surgery is rare, and is usually conned
to the situations of intraoperative bleeding that cannot be controlled laparoscopically, inability to safely progress in the dissection of large tumors, or patient factors
such as obesity or inability to tolerate pneumoperitoneum.
A. Papachristos and S. B. Sidhu
2 Preoperative Preparation
The details of the pre-operative work-up are beyond the scope of this chapter. A
thorough understanding of the relevant endocrine pathophysiology is essential in
the interpretation of the screening and diagnostic tests, and it is crucial that nature
and severity of autonomous function is dened prior to surgical management.
Depending on the pathology, the patient may have profound uid and electrolyte
imbalance, or hemodynamic abnormalities. A full preoperative workup for
Cushing’s syndrome, hyperaldosteronism and pheochromocytoma is described in
detail by Kebebew in a recent review article [6]. The secretion of multiple hormones, particularly the combination of cortisol and androgens, is one of the hallmarks of ACC, and is an adverse prognostic factor [7].
At induction, it is our practice to administer chemical DVT prophylaxis.
Pneumatic calf compressors are applied and an indwelling bladder catheter is
placed. In patients with autonomous cortisol secretion, stress steroid dosing is initiated. In symptomatic pheochromocytoma, it is our practice to routinely prepare
these patients with pre-operative alpha blockade, and this is ceased on the day of
surgery.
3 Surgical Approach
The anterior transperitoneal approach to the adrenal allows extensive exposure and
provides options for vascular control. We prefer a subcostal incision to a midline
incision, as it provides better access to the superolateral aspects of the surgical eld.
This can also be extended across midline, or combined with a midline incision if
Open Adrenalectomy
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Fig. 1 The patient is on a
bean-bag with a lateral
wedge on the contralateral
side of the pathology. The
operating table is then
broken to maximize the
space between the costal
margin and the iliac crest.
The bean bag is then
suctioned to rmness to
secure the patient in place
57
required. Rarely, it may be combined with a sternotomy to allow cardiopulmonary
bypass for excision of extensive tumor thrombus. The posterior open approach
affords less exposure. Historically, it was indicated in patients with smaller, localized tumors, however these patients are now treated with minimally invasive
techniques.
3.1 Patient Positioning
The patient is placed supine on the operating table on a bean-bag with a lateral
wedge on the side of the pathology. A more pronounced lateral decubitus position
(Fig.1) can be utilized based on surgeon preference. The costal margin is marked,
as well as the planned incision two nger-breadths inferior to this. The operating
table is then exed to accentuate the space between the costal margin and the iliac
crest. Once appropriately positioned, the bean-bag is connected to suction and the
patient is strapped to the operating table at multiple points.
4 Description ofProcedure
The specic anatomical considerations differ for right- and left-sided tumors. Below
we describe the specic approach to each side, adhering to the following general
considerations:
• The importance of an R0 resection cannot be overstated and therefore preserving
the integrity of the tumor capsule is of paramount importance.
• If large adrenal tumors are invasive, they typically involve retroperitoneal struc-
tures, and are usually contained anteriorly by Gerota’s fascia.
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