Endoscopic Neck Surgery
Last updated date: 12-May-2023
Originally Written in English
Endoscopic Neck Surgery
The neck area is made up of a variety of well-defined anatomic structures that are organized in layers with minimum or no vascular overlap. The endoscopic surgeon has used these well-defined layers to establish vascular anatomical planes in order to create a working environment for surgical manipulation. Endoscopic neck surgery, first reported in 1996, has expanded in its application, owing to its aesthetic benefits. Although few studies have reported on its use in other neck structures, such as the submandibular gland and cervical spine, the parathyroid and thyroid glands have been the primary target organs. In addition, total (pure) endoscopic (CO2 insufflation) techniques. Endoscopic and minimally invasive small incision methods with video assistance. Supraclavicular, anterior chest wall, axillary, and periareolar breast approaches are all variations of the total endoscopic approach. In the video-assisted endoscopic method, the last three have also been tried.
Endoscopic Spinal Surgery
Endoscopic spine surgery (ESS) is a minimally invasive surgical treatment for treating chronic back and leg pain.
An HD camera coupled to an endoscope is placed via a 14-inch surgical incision to the target pain generator in your spine in this cutting-edge spine surgery.
Endoscopic orthopedic surgery allows spine surgeons to operate more safely and accurately, resulting in better outcomes for patients.
The surgeon can use an HD monitor to view the spine and work with highly specialized micro-instruments such as a laser, radiofrequency probe, or graspers using the endoscope.
Differentiated thyroid carcinoma is the most common endocrine malignancy, and treatment is improving fast in recent decades. For the past few decades, conventional thyroidectomy has been a developed, safe, and effective treatment for differentiated thyroid cancer, however, one incisional scar in the anterior lower neck is unavoidable. The scar is a permanent cosmetic imperfection that has an impact on the aesthetic outcome. Furthermore, as a drawback of standard thyroidectomy, such a scar might cause cervical hyperesthesia, paresthesia, and feelings of self-consciousness.
Laparoscopic surgery has evolved to meet the demands of aesthetics, recovery, and minimal trauma in practically all surgical specialties, including the treatment of differentiated thyroid cancer. In 1996, Gagner published the first report on endoscopic neck surgery. In 1997, Hüscher et al. performed a video-assisted thyroid lobectomy. Ikeda et al. and Ohgami et al. used various ways to turn endoscopic thyroidectomy (ET) into a scarless procedure. Miccoli et al. performed a successful invasive video-assisted thyroidectomy for papillary cancer in the 2000s. In the decade that followed, many scarless endoscopic thyroidectomy (SET) procedures were introduced. Several studies looked at the effectiveness of ET for thyroid cancer. Because of the great cosmetic satisfaction and lack of faults, this procedure has received worldwide interest and attention.
Endoscopic Thyroidectomy Benefits
SET has a better cosmetic outcome than traditional thyroidectomy. Jiang et al. confirmed that SET is more visually appealing than open thyroidectomy. ET also has the added benefit of greatly lowering the incidence of hyperesthesia, paresthesia, and swallowing pain. Furthermore, postoperative pain with SET is less severe. The severity of postoperative pain in the conventional group was much higher on the first day than in the endoscopic group, according to Jiang's research, but the difference was not evident after 48 hours.
Endoscopic Thyroidectomy Disadvantages
SET is a technically difficult operation with a significant learning curve. Del Rio et al. showed their minimally invasive endoscopic thyroidectomy learning curve. The mean operative time for the first 50 cases (a total of 100 cases) was significantly longer than for the last 50 cases. Tan et al. reviewed current studies and concluded that SET (through the axilla or breast) is not a minimally invasive procedure, but only scarless in the neck. It takes longer to perform, causes more postoperative discomfort, and causes more serious harm than the standard method. Certain patients who undergo ET still face the possibility of converting to open surgery. In comparison to conventional surgery, endoscopic methods make dealing with arterial bleeding and big tumors more difficult. The cervical group had a conversion rate of 2.2 percent, which was higher than the extracervical group (0.42 percent). On the other hand, multicentral, large sample, prospective studies give minimal evidence that SET can provide a satisfactory recurrence rate.
Endoscopic Thyroidectomy Indications
The benefits of surgery employing minimally invasive procedures have been well-proven. This type of surgery has also been introduced into the field of differentiated thyroid cancer treatment for a variety of purposes, including enhanced vision and good cosmesis. Early on, ET was only used to treat benign thyroid tumors, with malignant tumors being one of the contraindications. The indications for ET are always being extended and completed as operating equipment and personal skills improve. Throughout the years, many reports have revealed varying indications of ET for thyroid cancer.
Endoscopic Thyroidectomy Contraindications
The following are regarded as relative contraindications: (1) malignancy with thyroiditis; (2) a clinical history of radiation or neck surgery. Absolute contraindications include (1) a tumor with a diameter greater than 3.5 cm; (2) a thyroid gland volume greater than 30 mL; (3) evidence of local or distant metastases; and (4) age higher than 50 years. If the thyroid carcinoma has several foci, infiltrates to the thyroid membrane or anterior jugular muscles, or lymph node metastases, ET is not recommended.
Endoscopic Thyroidectomy Procedure
The operating technique is divided into ten surgical steps, each of which is overviewed and in chronological order:
- Surgical access, ports, and operating space formation. The surgical access is divided into two categories: cervical and extracervical routes. Transaxillary (TA), chest wall (CW), and axilla-breast (AB) accesses are the most common extracervical routes. It's too early to say whether one strategy is better than the other. A camera port and two working ports are typically utilized, with an additional port available as an alternative.
- Reaching thyroid gland in visceral space of neck. In ET, the thyroid goiter (TG) can be reached through the midline between the strap muscles or the lateral approach between the strap muscle and the sternocleidomastoid (SCM) muscle, identical to open thyroidectomy. Because it is an avascular plane that avoids anterior jugular veins and helps in direct control of the middle thyroid vein, this lateral technique is very useful in ET. The deep fascia across this plane is cut using diathermy, and the SCM is retracted. For increased space, the lateral one-third of the strap muscles might be cut. Clips are used to control the middle thyroid vein.
- Thyroid gland mobilization. The avascular line between the thyroid lobe and the carotid sheath is further opened up to the prevertebral fascia. Close to TG, the pretracheal fascia across the thyroid lobe is stretched and turned medially. This procedure is repeated until the lateral part of the superior thyroid pedicle is visible.
- Control of the superior thyroid pedicle. The strap muscle overlaying the TG is retracted, and the lateral one-third of the muscle is cut if necessary. Once the superior pedicle blood vessels have been identified, they must be skeletonized by using bipolar diathermy to remove the pretracheal fascia and strap muscle fibers. Individually clipped pedicle blood vessels are doubly clipped on the proximal side and singly clipped toward the TG. They are split in order to devascularize TG more effectively.
- Control of the inferior thyroid pedicle. The trachea below the ipsilateral isthmolobar junction is seen using a mix of blunt and sharp dissection assisted by diathermy. From the medial to the lateral side, the multiple inferior thyroid veins (ITVs) should be skeletonized. Individual ITVs are trimmed and split. Because the lateral most ITV runs parallel to the recurrent laryngeal nerve (RLN), it must be identified before being divided. If in doubt, divide the lateral ITV only after the RLN demonstration. It is easier to recognize ITV from RLN with endoscopic magnification than it is with open surgery.
- Recurrent laryngeal nerve (RLN) identification. Because ET is frequently performed on smaller goiters, the RLN is usually found in a normal location. It runs between the branches of ITA in the trachea-esophageal groove. RLN is observed as a white string-like structure dorsal to TG with a vasa nervosum accompanying it under endoscopic magnification. To divide vascular structures, a low-amperage diathermy current is used at least 2 mm away from the RLN. RLN is followed until it reaches the inferior pharyngeal constrictor's lower border.
- Parathyroid glands (PT). To recognize parathyroid glands (PT), you'll need a lot of anatomical and embryological understanding, as well as a lot of thyroid surgery experience. They should be found in the usual anatomical sites. In more than 80% of people, superior PT, which is the most consistent, is found posterosuperior to RLN. To protect PT, a capsular dissection near the TG capsule is performed with careful hemostasis utilizing bipolar diathermy. The inferior pole of the thyroid is divided and preserved similarly to superior PT, which is placed anteroinferior to RLN.
- Ligament of Berry. The division of the posterior suspensory ligament of the thyroid, commonly known as the ligament of Berry, is the eighth and last step of ET. Because the ligament of Berry is a vascular structure, it is separated close to TG and apart from RLN using bipolar diathermy once RLN is identified across its full course.
- Separation of TG from thyroid bed. After the preceding steps, the only connection of TG in the neck is fragile, hypovascular areolar tissue between TG and tracheal perichondrium. After raising the TG off the trachea, it is separated with sharp dissection utilizing scissors.
- Specimen extraction. For total thyroidectomy, the procedure is repeated on the opposite side. After extending the incision by 1–2 cm, the thyroidectomy sample is extracted from the camera port under eyesight. Drain placement is optional after assessing for hemostasis in the thyroid bed.
Endoscopic Thyroidectomy Risks
CO2 has a high diffusion capacity. Because the area is devoid of a serous membrane, the body may absorb more CO2 during SET than during abdominal surgery. Patients who have a pressure greater than 6 mmHg may develop hypercapnia, pneumohypoderma, and mediastinal emphysema. Fat liquefaction, incision dehiscence, wound infection, and ecchymosis can all result from the separation of subcutaneous tissue.
The recurrent laryngeal nerve (RLN) and the parathyroid gland injury are two of the most serious consequences of SET. The chance of having a transient or permanent RLN injury varies substantially, ranging from 0% to 11%. Because the surgical tools used in VAT and conventional surgeries are similar, they have similar problems. Raffaelli et al. reported on a study with a somewhat large population. In 359 cases of VAT, 11 patients had acute RLN paralysis, 90 had temporary hypocalcemia, and 4 developed permanent hypocalcemia. There is no statistical difference between VAT and traditional surgery. Chung et al. found that 25 percent of TET patients had transitory hypocalcemia, whereas 1 percent developed permanent hypocalcemia. The rate of temporary RLN paralysis is 25 percent, which is higher than the standard operation, although none of them is permanent. As a result, SET provides a risk-free alternative to open thyroid surgery.
The parathyroid glands, according to Gagner in 1996, are accessible for endoscopic treatment due to their size. Their changeable position is a disadvantage. Minimally invasive parathyroidectomy has progressed as imaging and localization techniques have improved, allowing for a more targeted approach.
Endoscopic Parathyroidectomy Preoperative Assessment
Preoperative imaging tests in patients who are candidates for a video-assisted, minimally invasive endoscopic parathyroidectomy (MIVAP). Tc-99m-sestamibi and SPECT-CT images, respectively, show a parathyroid lesion posterior to the inferior pole of the right thyroid. Transverse and longitudinal ultrasound imaging showed a hypoechoic lesion posterior to the right lower thyroid, which was in concordance.
Because 80 percent of patients coming for parathyroid surgery have sporadic primary hyperparathyroidism caused by a single adenoma, MIVAP should be considered in the majority of cases. Most authors, however, claim that MIVAP candidates are approved in lower numbers than expected, with eligibility percentages ranging from 35 to 80 percent. The incidence of thyroid cancer in a patient population, the reliability of preoperative imaging techniques in each specific facility, and the availability of intraoperative parathyroid hormone (IOPTH) testing all play a role in patient eligibility for MIVAP.
The surgeon's expertise and familiarity with the procedure will also determine eligibility. Some surgeons have gradually broadened the inclusion criteria to include patients with intrathymic adenomas, multigland disease necessitating bilateral surgery, nodular thyroid disease, or previous contralateral neck surgery. The eligibility rate has been reported as high as 80 percent when the inclusion criteria are additionally broadened to include patients with nonlocalizing or discordant imaging.
Endoscopic Parathyroidectomy Procedure
The targeted minimally invasive tiny incision approach is the most popular minimally invasive approach for conducting parathyroidectomy. There are few publications available for total endoscopic parathyroidectomy, reporting on a small number of patients. Currently, the minimal access technique, also known as minimally invasive parathyroidectomy (MIP), is used for just under half of all parathyroidectomies. Selection criteria such as unilateral pathology (ideally a single adenoma), absence of thyroid enlargement, no previous neck surgery, and no prior history of radiation to the neck region limit its application.
Intraoperative quick parathormone testing, frozen section, and sound clinical judgment, followed by postoperative serum Ca++ and PTH level monitoring, were all used to achieve full resection of the hyperfunctioning parathyroid tissue in MIP. Day-care MIP with local anesthetic has also been reported in a few studies. Such facilities use techniques like the chemiluminescent assay for intact PTH level (quick PTH), which has a success rate of 96-98%, to ensure that the patient is healed before being discharged. Patients with uniglandular disease, on the other hand, show the best outcomes. Whether or not an intraoperative PTH assay is conducted, a MIP will cure the patient if a careful preoperative patient selection is undertaken.
Endoscopic Parathyroidectomy Outcomes
MIVAP success depends on careful patient selection, surgeon competence and expertise, and the accurate use and understanding of perioperative adjuncts including imaging tools and the IOPTH assay. Cure rates with MIVAP have been proven to equal or exceed the 95 percent success rate with typical bilateral neck exploration when these aspects are coupled. Del Rio et al found no significant differences in the recurrence rates between MIVAP and traditional four-gland exploration in one of the few reported studies (2.6 percent vs. 3.7 percent, respectively). When MIVAP is conducted on patients with localizing imaging scans and IOPTH testing, other authors have consistently reported cure rates of greater than 97 percent.
When compared to unilateral open surgery without an IOPTH test, routine use of the IOPTH test enhances the cure rate and reduces operative time in minimally invasive parathyroid surgery, including MIVAP. The sensitivity of IOPTH in MIVAP is 97 percent, with an 87 percent specificity, a 99.5% positive predictive value, and a 97 percent accuracy. IOPTH directly enhanced cure rates in minimally invasive parathyroid surgery from 91 to 99 percent, according to Barczyski et al, and is especially useful in patients who had only one positive preoperative localization scan. When compared to standard bilateral neck exploration, IOPTH testing in MIVAP reduces the unintentional removal of physiologically normal parathyroid glands and may contribute to the lower incidence of hypocalcemia found in MIVAP.
Endoscopic Parathyroidectomy Risks
- Recurrent Laryngeal Nerve Injury. In MIVAP, recurrent laryngeal nerve injury is infrequent, with temporary injury occurring in up to 2.5% of cases and permanent injury occurring in only 0.9 percent of cases. These low rates compare favorably to traditional bilateral neck exploration, and are most likely attributable to the endoscope magnified view of the RLN and the limited degree of dissection around the nerve.
- Hypocalcemia. In about 13% of patients, traditional bilateral parathyroid surgery causes temporary postoperative hypocalcemia; this rate rises to 24% if the glands are biopsied. After bilateral exploration, up to 2.5 percent of individuals develop permanent hypocalcemia. When only one gland is treated in specialized minimally invasive procedures like MIVAP, the risk of hypocalcemia is lowered. After MIVAP, up to 11 percent of patients experience transient hypocalcemia, while only 0.5 percent of patients experience permanent hypocalcemia. In comparison to traditional surgery, unilateral parathyroid surgery is accompanied by less severe hypocalcemia and lower postoperative calcium needs.
Endoscopic neck surgery has a distinct cosmetic benefit over traditional neck surgery. This operation would be performed in more centers as expertise and patient demand increase. However, it is recommended that patients be carefully chosen. Though a few institutes have reported positive results in thyroid cancer, the role of endoscopy in thyroid cancer is still debated. Other neck structures, such as the submandibular gland, are still at the experimental stage when it comes to endoscopic approaches.