**1. Introduction**

Transoral videolaryngoscopic surgery (TOVS) for laryngopharyngeal cancer was developed by Shiotani and his colleagues in Japan since 2004 and the first report was published in 2010 [1–4]. This novel endoscopic transoral surgical system uses the laparoscopic surgical system and distending laryngoscope which enables en bloc resection under a good view with videoendoscope. Recently, surgical instruments used in TOVS have been modified to some extent. Good long-term survival, larynx preservation, and functional outcomes were reported [5]. In this chapter, the tips and the pearls of TOVS including detail of the surgical procedures, managements, and outcomes are described.

## **2. The feature of TOVS**

The break out of transoral surgery for laryngopharyngeal cancer was started from transoral laser microsurgery (TLM), developed by Steiner et al. [6]. TLM is suitable for glottic lesions which are required fine and precise maneuver in a limited narrow space. Although TLM yields good oncological outcomes, the microscopic view through a rigid laryngoscope is linear and is not wide enough to observe the entire laryngopharynx. Particularly when observing the postcricoid area and inner surface of the epiglottis, it is often hidden by the blade of the laryngoscope. Multiple repositioning of the laryngoscope is also needed when the lesion is relatively large. In addition, pathological workup is difficult when piece-by-piece resection is performed.

To overcome these drawbacks, TOVS was developed. The endoscopic view under a flexible videoscope is wider than that under a microscope, and a wide working space can be achieved by using the FKWO retractor. This method enables detailed observation, precise procedures, and en bloc resection in the structurally complex laryngopharynx.

Although transoral robotic surgery (TORS) is actively performed for hypopharyngeal cancer in South Korea, tracheostomy is required because the intubation tube interferes with the arms of the robot [7]. In TOVS, a videoscope and forceps with a smaller diameter than the arms of the robot are used; hence, surgical procedure without tracheostomy is possible even in the narrow and distal spaces such as the hypopharynx. In addition, the surgeon has tactile sense through instruments. Therefore, TOVS has some advantages in maneuver and is less invasive compared to TLM and TORS, particularly for hypopharyngeal cancer.

#### **3. Indications**

The major indications for TOVS are Tis, T1, and T2 lesions of hypopharyngeal, oropharyngeal, and supraglottic laryngeal cancer. TOVS is also indicated for selected T3 lesions without deep invasion. Furthermore, TOVS is considered for small radiation failure cases (rT1 and rT2) if the lesions are resected with enough margins [8]. TOVS is also considered in advanced T3 or T4 cases after the tumor shrinks to a limited area following neoadjuvant chemotherapy (NAC). However, it is not a standard indication due to issues in the resection area, possibly leading to oncologically inadequate resection, as described in Section 11.3 (**Table 1**).

Anatomical contraindications for TOVS are cricoarytenoid joint fixation due to cancer invasion, circumferential invasion of more than half of the esophageal inlet, bilateral arytenoid invasion, and invasion to the thyroid cartilage, cricoid cartilage, hyoid bone, deep pharyngeal constrictor muscle, hard palate, and pterygoid hamulus. Oncologically sufficient resection is technically difficult, and functional preservation may not be excellent because of dysphagia and respiratory disorders due to postoperative stenosis and vocal cord movement restriction.

Patients with resectable lymph node metastases are treated by neck dissection (ND) along with TOVS on the same day or 1–2 weeks later. TOVS is generally performed in N1–N2 cases; however, although they are technically resectable, TOVS is not generally indicated in N3 cases due to poor prognosis [5]. Considering that postoperative chemoradiotherapy is needed in most N3 cases, transoral surgery has little significance due to increased invasiveness without improvement in oncological outcomes.

Although the extent of lesions is the basis of decision making for surgical indications, the final decision is made by considering the systemic condition. Preoperative swallowing function should be evaluated in cases predisposed to dysphagia, and surgical indication should be conservatively decided. Age; performance status;

*Transoral Videolaryngoscopic Surgery (TOVS) DOI: http://dx.doi.org/10.5772/intechopen.97473*


#### **Table 1.**

*Indications for TOVS.*

medical history including radiation history; comorbidities such as respiratory diseases, cardiovascular diseases, and diabetes; and family environments should also be considered.

#### **4. Devices**

The FKWO retractor (**Figure 1a**, Olympus medical systems, Tokyo, Japan) with various blades is used to expose the laryngo-hypopharynx and widen the operative field of view in most cases. Weerda distending video laryngoscope (8588BV; Karl Storz, Tuttlingen, Germany) is also useful.

Endoeye flex (LTE-S190–5, Olympus Medical Systems, Tokyo, Japan; **Figure 1b**), an HD videoendoscope with a thin 5-mm diameter and an articulating tip that can bend in all directions up to 100°, is used to observe the surgical field in most cases. This endoscope is suitable to observe the structurally complex laryngopharynx with minimal device conflict during transoral surgery. In addition, it has the function of image-enhanced endoscopy (narrow-band imaging: NBI), which is useful for evaluating the extent of mucosal lesions. A rigid laryngeal endoscope (8575AV; Karl Storz), connected to a high-definition camera set (22220150–3; Karl Storz), also provides a wide and clear view.

For forceps, scissors, electrocautery electrodes, suction coagulators, and clip applicators, reusable straight devices are used. Incision and separation are performed using laparoscopic surgical instruments measuring 3 mm in diameter connected to an ordinary electrocautery unit, including separating (30721MD; Karl Storz) or scissor-type (30721 MW; Karl Storz) tip forceps and hook-type (26870UF; Karl Storz) or needle-type (26167NX; Karl Storz) scalpels. For hemostasis, a suction coagulator (8606E; Karl Storz) or hemostatic clips (8665 L and 8665R; Karl Storz) are used (**Figure 1c**).

New malleable or curved devices, including LaryngoFIT forceps and scissors (8791GHZ, 8793AZ, 8791AZ, and 8794AZ, Karl Storz, Tuttlingen, Germany), a malleable needle electrocautery electrode (KD600, Olympus medical systems, Tokyo, Japan), a fiber guide CO2 laser (AcuPulse DUO, Lumenis, Yokneam Illit, Israel), and a malleable suction coagulator (7030010, Amco, Tokyo, Japan), have been recently shown to be very helpful (**Figure 1d**). Most of these devices have a

#### **Figure 1.**

*Devices for TOVS. a. FKWO retractor, b. Endoeye flex, c. straight devices - forceps, scissors, electrocautery electrodes, suction coagulators, and clip applicators, d. malleable and curved devices - curved forceps, malleable forceps and scissors, malleable needle electrocautery electrode, malleable suction coagulator, curved suction, malleable and curved handpieces of fiber guide CO2 laser.*

thin shaft of approximately 3 mm in diameter, except for the malleable suction coagulator, which has a thin shaft measuring 5 mm in diameter. These devices are effective for approaching from any direction in the view of the endoscope, allowing the surgeon to make parallel or perpendicular cuts along the line of sight [5].
