Modified Radical Neck Dissection for Cervical Metastasis

Summary

Here, we present a protocol for radical neck dissection integrating oncologic resection, cranial nerve preservation, and functional reconstruction in cervical metastasis.

Abstract

Radical neck dissection (RND) has stood as the cornerstone surgical procedure for managing controlled cervical metastatic disease for over a century. This comprehensive intervention involves the en bloc resection of the tissue contents within the major cervical triangles, bounded by the deep muscular layer and the investing cervical fascia. The anatomical boundaries extend from the inferior border of the mandible superiorly to the clavicle inferiorly, and from the midline anteriorly to the anterior border of the trapezius muscle posteriorly. A standard RND specimen systematically incorporates the sternocleidomastoid muscle (SCM), the internal jugular vein (IJV), the spinal accessory nerve (CN XI), and the lymphatic tissue encompassing levels I through V. However, evolving surgical practice often favors a modified Radical neck dissection (MRND) approach, which preserves non-lymphatic structures such as the IJV and CN XI when not overtly involved by disease, to minimize functional morbidity without compromising oncologic efficacy. This video article delineates a meticulous, step-by-step protocol for performing a radical or modified radical neck dissection, emphasizing critical technical nuances for achieving complete oncologic resection, preserving vital neurovascular structures-including the marginal mandibular nerve, vagus nerve, and phrenic nerve-and undertaking functional reconstruction. Key advantages of our protocol, demonstrated through a representative case, include a high rate of successful nodal clearance, a minimal postoperative complication profile (e.g., <5% rate of chyle leak or major hematoma), and excellent functional outcomes in shoulder abduction and facial symmetry due to precise nerve preservation techniques. This procedural demonstration serves as a valuable educational resource for surgeons mastering this complex and widely performed operation in head and neck oncology.

Introduction

Radical neck dissection (RND) has remained the definitive surgical procedure for managing cervical metastatic disease throughout the past century¹. This comprehensive intervention entails the en bloc resection of all tissue compartments bounded superficially by the cervical fascia and deeply by the deep muscular layer². Its anatomical boundaries extend from the inferior border of the mandible superiorly to the clavicle inferiorly, and from the midline anteriorly to the anterior border of the trapezius muscle posteriorly. The resection specifically encompasses the cervical lymphatic network (levels I-V) along with associated afferent and efferent vessels. Crucially, the procedure emphasizes the preservation of critical neurovascular structures through meticulous dissection within fascial planes³.

Cervical lymph node metastasis in head and neck squamous cell carcinoma necessitates aggressive surgical management that balances oncological radicality with functional preservation⁴. Traditional RND, which resects the spinal accessory nerve (CN XI), internal jugular vein (IJV), and sternocleidomastoid muscle (SCM), is associated with significant functional impairment, such as shoulder syndrome and cosmetic deformity⁵. In response, modified radical neck dissection (MRND) and functional neck dissection (FND) have evolved to preserve non-lymphatic structures unless invaded, improving postoperative quality of life without compromising oncologic outcomes⁶. It is important to note that RND, MRND, and FND differ in their indications and anatomical extent and should not be used interchangeably⁷.

This protocol introduces a refined RND approach that integrates extended lymphadenectomy with intraoperative nerve monitoring and layered fascial reconstruction. It is particularly advantageous for tumors involving Levels II-IV or cases requiring submandibular gland excision⁸.

The technique aims to address two major challenges: (1) achieving a balance between comprehensive tumor removal and neural integrity⁹, and (2) reducing dead space to prevent seroma formation¹⁰. Preliminary data from 30 patients demonstrate a 90% 2-year survival rate with reduced rates of cranial nerve dysfunction and seroma, supporting its clinical viability.

Protocol

The protocol presented here has been approved and conducted as per the guidelines of the West China Hospital of Stomatology. The patients in this study underwent routine surgical procedures with no investigational interventions performed. All patients provided signed informed consent for surgery and use of the data for this study.

1. Preoperative preparation

1. Position the patient supine with the head turned to the healthy side and slightly extended.
2. Following the induction of general anesthesia with intravenous agents, a lubricated endotracheal tube was inserted through the nostril and advanced into the trachea under direct laryngoscopy.
3. Correct placement was confirmed by capnography.
4. Anesthesia was maintained with a combination of inhaled volatile anesthetics and intravenous infusions.
5. Elevate the shoulders to flatten the supraclavicular fossa.

2. Incision and exposure

1. Perform a quasi-rectangular incision.
   1. Make a transverse incision from the chin midline to 2 cm below the mandibular margin, ending below the mastoid process.
   2. Extend a longitudinal incision along the trapezius muscle's anterior edge to the middle/lower 1/3 junction (3-4 cm above the clavicle).
   3. Curve downward and forward over the clavicle midpoint, ending 3 cm below the clavicle. The completed rectangular incision design is shown in Figure 1.
2. Incise the platysma muscle with a scalpel or tissue scissors. Cover wound edges with sterile towels.

3. Flap elevation

1. Elevate the rectangular flap sharply from the platysma's deep surface.
2. Extend the submental incision 1 cm above the mandibular margin.

4. Sternocleidomastoid muscle dissection

1. Separate the muscle's clavicular insertion using curved hemostats. Transect the clavicular and sternal heads 1-1.5 cm above the clavicle.
2. Ligate cut ends and elevate the muscle. Incise the carotid sheath; identify the internal jugular vein, common carotid artery, and vagus nerve.

5. Internal jugular vein dissection

1. Make a longitudinal incision along the carotid sheath's medial side.
2. Ligate all branches draining into the vein.
3. Mobilize the sheath superficially and laterally to ensure en bloc lymphoid removal.

6. Accessory nerve preservation

1. Identify the accessory nerve at the trapezius muscle's mid-lower 1/3 junction.
2. Dissect proximally along the nerve, preserving it if uninvolved by tumor.

7. Surgical field boundaries

1. Lower boundary:
   1. Identify the phrenic nerve beneath the prevertebral fascia.
   2. Ligate the external jugular vein, suprascapular vessels, and transverse cervical vessels 1 cm above the clavicle.
   3. Transect the supraclavicular adipose tissue and omohyoid muscle.
2. Anterior boundary:
   1. Incise the deep cervical fascia along the sternohyoid muscle.
   2. Retract the sternocleidomastoid muscle; transect the omohyoid at its hyoid attachment.
3. Posterior boundary:
   1. Dissect the trapezius's anterior margin upward to the mastoid.
   2. Ligate adipose tissue and vascular branches; preserve the accessory nerve.

8. Base dissection and critical structures

1. Lift the tissue block and dissect along the prevertebral fascia toward the mastoid. Ligate cervical plexus branches; avoid injuring the brachial plexus and phrenic nerve.
2. Transect the sternocleidomastoid muscle at the mastoid tip with electrocautery. Resect the parotid's lower pole; ligate the posterior facial vein and external jugular vein.
3. Preserve the marginal mandibular nerve if feasible.

9. Submandibular/submental dissection

1. Incise the deep fascia along the mandible; preserve the marginal mandibular nerve. Ligate the facial artery and vein.
2. Dissect the submandibular gland and nodes; identify the hypoglossal and lingual nerves. Ligate the submandibular duct near its orifice to spare the lingual nerve.

10. Wound closure

1. Irrigate the cavity with normal saline; apply diluted povidone-iodine solution. Place a double-tube negative-pressure drain in the wound's lowest point.
2. Suture in layers (platysma, subcutaneous, skin). Secure the 60 mL drain with a 3-0 purse-string suture; apply a light dressing.

Results

After the surgery, the entire removed cervical tissue is shown in Figure 2. Figure 3 shows the important anatomical areas that can be directly observed after the cleaning and thorough hemostasis have been completed. Thirty complete lymph nodes were isolated from the cervical tissues, as shown in Figure 4. The postoperative pathological examination has confirmed the diagnosis, and the treatment process has been completed according to...

Discussion

This open neck dissection protocol provides a systematic approach to two fundamental challenges in managing cervical metastasis: achieving oncologically radical resection while preserving neural function, and eliminating dead space through fascial flap reconstruction. Balancing oncological safety with functional outcomes remains critical for long-term patient prognosis¹.

Meticulous dissection of neural structures (spinal accessory, vagus, and phrenic nerves) using bipol...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
3-0 antibaterial vicryl absorbable suture	Johnson (Suzhou) Medical Devices Co., Ltd.	VCP1772D	For tissue suturing
DSRobot 4K-Station	Digital Vision	-	Surgery video recording
High-Frequency Electrosurgical Unit	Guangdong Baisheng Medical Equipment Co., Ltd.	OBS-350A	Precise tissue cutting and coagulation
Ultrasonic cutting and hemostasis system	Tianjin Ruiqi Surgical Instrument Company	CSUS6000	For cutting and hemostasis