HEAD AND NECK

Transoral robotic surgery for the management of head and necktumors: learning curve

Georges Lawson • Nayla Matar • Marc Remacle •

Jacques Jamart • Vincent Bachy

Received: 1 December 2010 / Accepted: 7 February 2011 / Published online: 2 March 2011

� Springer-Verlag 2011

Abstract Transoral robotic surgery (TORS) is an

emerging technique for the treatment of head and neck

tumors. The objective of this study is to describe our first

steps and present our experience on the technical feasibil-

ity, safety, and efficacy of TORS for the treatment of

selected malignant lesions. From April 2008 to September

2009, 24 patients were enrolled in this prospective trial.

Inclusion criteria were: adults with T1, T2 and selected T3

tumors involving the oral cavity, pharynx, and supraglottic

larynx and a signed informed consent was obtained from

the patient. Exclusion criteria were: tumors not accessible

to TORS after unsuccessful attempts to expose properly the

lesion to operate. The ethical committee’s approval was

obtained to perform this study. Twenty-four patients were

included in this study: 10 supraglottic tumors, 10 pharyn-

geal tumors and 4 oral cavity tumors. Nine patients had T1

tumors, 12 had T2 tumors, and 1 patient had a T3 tumor. In

all cases, tumor resection could be performed by robotic

surgery exclusively and negative resection margins were

achieved with control by frozen section. None of them

received intraoperative reconstruction. None of the patients

required tracheotomy. There was no intraoperative com-

plication related to the use of the robot. The average setup

time was 24 ± 14 min (range 10–60 min). The average

surgical time was 67 ± 46 min (range 12–180 min). Sur-

gical and setup time decreased after the first cases. The

mean hospital stay was 9 days. Oral feeding was resumed

at 3 days. TORS seems to be a safe, feasible, minimally

invasive treatment modality for malignant head and neck

tumors with a short learning curve for surgeons already

experienced in endoscopic surgery.

Keywords Transoral robotic surgery � Squamous cell

carcinoma � Learning curve � Supraglottic neoplasms �Pharyngeal neoplasms � Oral cavity neoplasms �Prospective study

Introduction

Minimally invasive procedures are becoming a target to

reach in many fields of surgery. With this regard, transoral

laser microsurgery (TLM) is the most accepted approach

for early laryngeal and pharyngeal cancers, instead of open

partial procedures, when surgery is indicated [1, 2].

However, even with advancements over the past

30 years, TLM continues to have disadvantages, including

the operator’s distance from the surgical field, the laryn-

goscopes’ limited exposure, and reduced depth perception

with binocular vision [3]. Robotic surgery has the potential

to address the shortcomings of TLM; however, it was

introduced in the field of otolaryngology a decade after its

use in laparoscopic, thoracoscopic, cardiac, and urologic

surgical procedures [4].

Abstract accepted for oral presentation at the European

Laryngological Society, September 1–4, 2010, Vienna, Austria.

G. Lawson � M. Remacle (&) � V. Bachy

Otolaryngology-Head and Neck Surgery Department,

Louvain University Hospital of Mont-Godinne,

Dr Therasse Avenue, No. 1, 5530 Yvoir, Belgium

e-mail: marc.remacle@uclouvain.be

N. Matar

Otolaryngology-Head and Neck Surgery Department,

Hotel Dieu de France Hospital, Bellevue Medical Center,

Saint-Joseph University, Beirut, Lebanon

J. Jamart

Scientific Support Unit, Louvain University Hospital

of Mont-Godinne, Dr Therasse Avenue, No. 1,

5530 Yvoir, Belgium

123

Eur Arch Otorhinolaryngol (2011) 268:1795–1801

DOI 10.1007/s00405-011-1537-7

Transoral robotic surgery (TORS) is defined as surgery

done via the oral cavity that uses a minimum of three arms

and allows bimanual surgical techniques [5]. Its intraop-

erative safety has been assessed in a study by Hockstein

et al. [6] on a fresh human cadaver. They concluded that

the da Vinci surgical system (Intuitive Surgical Inc, Sun-

nyvale, CA) demonstrates a safety profile similar to con-

ventional transoral surgery.

The first robotic procedure on a patient was carried out

in 2005 by McLeod and Melder [7] to excise a vallecular

cyst. In 2006, three patients with tongue base tumors

underwent TORS as part of a prospective clinical trial by

O’Malley et al. [8]. Since then a limited number of series

has been published in the literature [5, 8–11].

The da Vinci Surgical Robot was approved by the Food

and Drug Administration (FDA) for transoral surgery in

2009 [12].

Based on these findings, we decided to use TORS in

procedures where we considered TLM suboptimal

according to our experience and previously published lit-

erature [5, 8–11].

The team members received a specific training (both

theoretical and practical) related to the da Vinci surgical

system. The senior authors joined G. Weinstein (Depart-

ment of Otorhinolaryngology–Head and Neck Surgery,

University of Pennsylvania, Philadelphia) for 2 weeks of

laboratory training and clinical watching.

The objective of this prospective study is to evaluate the

technical feasibility, oncological and functional efficacy,

and safety of TORS in the treatment of malignant lar-

yngeal, pharyngeal and oral cavity tumors. We present the

first 18 months learning curve of a team who has previous

long experience with transoral microscopic laser surgery

[13, 14].

Materials and methods

From April 2008 to September 2009, 24 patients were

enrolled in this prospective trial on TORS using the da

Vinci Surgical Robot.

Inclusion criteria were: patients older than 18 years with

early stage tumors (T1, T2 and selected T3) involving the

oral cavity, base of tongue, pharynx, or supraglottic larynx,

who signed an informed consent. Exclusion criteria were:

medical conditions contraindicating general anesthesia;

patients with tumors not accessible to TORS after prior

evaluation under general anesthesia and attempts to place

various available retractors.

The ethical committee’s approval was obtained to per-

form this study. Procedures were documented with still and

video photography.

Patient’s assessment

We performed a preoperative work-up in all patients

including clinical examination, PET/CT, or CT with con-

trast of the neck, chest X-ray, liver function tests, direct

laryngoscopy and biopsy. During the general anesthesia for

direct laryngoscopy, we tried to position the appropriate

retractor to verify if the patient is eligible for TORS. In our

practice, direct laryngoscopy with biopsies is performed

systematically for every patient with a suspected tumor, to

assess the extension and have a histological confirmation of

the malignant nature of the lesion.

Anesthesia technique

An essential component of this procedure is the ability of

the surgeon to have an unobstructed view of the operating

field, this is why we used the smallest laser-safe endotra-

cheal tube possible for ventilation (inner diameter: 6 mm;

Hi/Lo, Mallinckrodt Medical, Athlone, Ireland). To allow

appropriate positioning of the mouth gag and cheek

retractor, the tube was not fixed with adhesives but care-

fully handled by the surgeon.

Surgical setting

All the procedures were performed in the same operating

room that was chosen between the largest ones available to

allow the placement of the equipments without impeding

the movements of the surgical and nursing team.

After the induction of anesthesia and the placement of

the endotracheal tube, the patient was rotated 180� away

from the anesthesia team. The surgical robotic cart was

positioned 30� from the surgical bed on the left side of the

patient. It is equipped with a robotic manipulator and four

mounted arms. However, we only used three of the robotic

arms: one arm held a 0� or 30� endoscope, and the other

two held 5-mm instruments. The vision cart is equipped

with 2 three-chip cameras mounted within one integrated

12-mm stereoscopic endoscope. This optical system creates

a wide-view high definition illusion of a 3D surgical field.

Its movable endoscope expands the surgical field by

changing viewing angles and position. The arms of the

EndoWrist� instruments (Intuitive Surgical Inc) have an

enhanced distal articulation design that provides flexion,

extension, pronation, and supination at the distal end of

instruments for finer tissue manipulation [3]. All proce-

dures were conducted using 5-mm EndoWrist� instruments

(a Maryland atraumatic forceps and an electrocautery

spatula tip). These instruments were introduced 30� later-

ally from the arm supporting the 0� endoscope and were

placed in the right or left arm of the robot, respectively,

1796 Eur Arch Otorhinolaryngol (2011) 268:1795–1801

123

depending on tumor localization and/or surgeon decision.

Places could be switched intraoperatively depending on the

surgeons’ preference.

The surgeon’s console was positioned away from the

patient, on his left side. The surgeon’s console displays a

three-dimensional view of the operative field by having a

separate monitor for the left and right eye views. At the

console, the surgeon controls the instrument arms and

camera by maneuvering the master robotic manipulators.

The assistant was seated at the head of the patient. The

video tower was on the right side of the patient.

Two cautery units were used: one electrocautery unit is

connected the arm fitted with the electrocautery spatula tip

and the second one is connected to a coagulating suction

tube handled by the second surgeon at the head of the

patient.

A table with suction tubes of various diameters, surgical

clips applier and various forceps used in TLM was placed

behind and to the left of the assistant (Fig. 1).

A double cheek retractor (Hager & Werken, Duisburg,

Germany) was used to protect the patient’s lips. Eye shields

were also used (EMS Medical Ltd, Gloucester, UK)

(Fig. 2). The Feyh-Kastenbauer (FK) retractor (Gyrus

ACMI, Southborough, MA) was used for most of the sur-

geries of laryngeal or pharyngeal tumors because it was,

until recently, the only one providing a good exposure of

the pharyngo-laryngeal region. A Crow-Davis retractor

was used for oral cavity tumors. A new retractor: the LARS

(Larynx advanced retractor system) retractor (Fentex,

Tuttlingen, Germany) designed by the senior authors (MR,

GL) was used in a small number of surgeries (Fig. 3). This

new retractor has several advantages. The framework

extends horizontally and makes the passage of the arms

through the mouth easier, there are easily adaptable and

removable vertical bars for the handling of instruments,

there are two screwing devices allowing the sliding

movement of the blade upward and downward as well as

backward and forward, finally the ratchet system can be

used starting from the beginning of the suspension process.

The retractor was suspended anteriorly with a Fentex

laryngoscope holder (Fentex, Tuttlingen, Germany).

For smoke aspiration in laryngeal and pharyngeal sur-

geries, a flexible aspiration tube, with continuous aspira-

tion, was introduced into the nasopharynx through the right

or left nostril and held in place with an adhesive tape.

Tumor resection followed the principles of the European

Laryngological Society for supraglottic tumors [13]. For

tonsil, base of tongue and hypopharyngeal tumors, the

techniques used were similar to those described by Wein-

stein et al. [10] for transoral robotic radical tonsillectomy,

Moore et al. [11] for base of tongue tumors and Park et al.

[9] for hypopharyngeal tumors.

Fig. 1 Surgical setting. 1 Da

Vinci robot 2 1st surgeon at the

console 3 2nd surgeon at the

patient’s head 4 Nurse at the

instruments table 5 2nd table for

Da Vinci robot devices 6 Rack

for imaging equipement

7 Anesthetist 8 Monopolar/

bipolar cautery

Eur Arch Otorhinolaryngol (2011) 268:1795–1801 1797

123

En bloc resection was always possible in this series.

Hemostasis was achieved using the suction-coagulation or

the surgical clips.

The surgical specimen was oriented on a cork plate for

histological examination after formalin fixation. Additional

margins from the surgical bed were taken in regions close

to the tumor to investigate the adequacy of tumor removal

and sent for frozen section analysis. Despite the thermal

effect of the monocautery, margin assessment was always

possible.

After tumor resection, the surgical field was covered

with a thin film of fibrin glue (Tissucol� Baxter, Vienna,

Austria) after the verification of the absence of communi-

cation between surgical field and the neck.

Management of the neck

Patients with negative necks on clinical and radiological

examination were enrolled in the sentinel node study

ongoing in our institution [15]. If the sentinel node was

positive for tumor invasion, neck dissection was performed

in the next 3 weeks. For patients with positive clinical and/

or radiological necks, unilateral/bilateral modified radical

neck dissection was performed in the same operation time

unless a major communication between the primary tumor

field and the neck was anticipated (tumors of the lateral

pharyngeal wall). In these cases, neck dissection was per-

formed during the next 3 weeks.

Postoperative care

No systematic tracheostomy was performed, but all patients

with laryngeal or pharyngeal resections were monitored for

24 h in the intensive care unit. All patients had systematic

steroids for 72 h and inhaled steroids for 1 week.

Patients in whom swallowing difficulties were antici-

pated had a small nasogastric feeding tube inserted during

the surgery. All the patients had intensive swallowing

therapy starting on the following day of the surgery.

Depending on the final histological report of the prod-

ucts of the tumor resection and neck dissection, adjuvant

radiation therapy or chemo-radiation therapy was decided

after discussion of the patients’ file on the tumor board.

Adjuvant radiation therapy was prescribed if there was

evidence on neck dissection of: two or more lymph nodes

involved with metastatic tumor or perineural or angi-

olymphatic invasion at the primary site. Adjuvant chemo-

radiation treatment was prescribed if there was extracap-

sular spread of tumor metastasis in one or more lymph

nodes or evidence of margins positive for tumor at the

primary site (with no possibility of extended surgery

without impeding organ preservation).

Swallowing exercises, neck and shoulder physiotherapy

and dietary counseling were planned in the postoperative

period.

Oncologic patients at our institution are evaluated with a

complete physical examination by the primary head and neck

surgery team every month for 6 months then every 3 months

for 1 year, then every 6 months for 3 more years, and then

yearly. A contrast-enhanced PET/CT scan is planned yearly or

as necessary depending on clinical examination.

Numerical variables were expressed as mean ± stan-

dard deviations and compared by Wilcoxon rank sum test.

Correlations were assessed by Spearman rank coefficient.

All tests are two-tailed and were performed using SPSS

15.0 statistical software (SPSS Inc., Chicago, IL).

Results

Twenty-four patients (23 men and 1 woman) were included

in this study. The mean age was 62 years (range 43–78

years). Ten patients had supraglottic tumors (6 epiglottic

Fig. 2 Double cheek retractor (Hager & Werken, Duisburg, Ger-

many) and eye shields (EMS Medical Ltd, Gloucester, UK)

Fig. 3 LARS retractor (Fentex, Tuttlingen, Germany)

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tumors, 2 ventricular fold tumors, 2 aryepiglottic fold

tumors), 10 had pharyngeal tumors (2 piriform sinus

tumors, 5 tonsil tumors, 1 tongue base tumor, 2 pharyngeal

wall tumors) and 4 had oral cavity tumors (tongue tumors).

Most of the patients had early tumors: 9 patients had T1

tumors, 12 had T2 tumors, and 1 patient had a T3 tonsil tumor.

The types or surgeries performed are as follows: 10

transoral robotic supraglottic laryngectomies, 5 transoral

robotic radical tonsillectomies, 4 transoral robotic partial

glossectomies, 5 transoral robotic partial pharyngectomies.

In all cases, negative resection margins were achieved

on frozen section analysis, and confirmed with routine

histological examination. None of them received intraop-

erative reconstruction.

Thirteen patients had N0 clinical and radiological necks,

5 were N1, 2 were N2a, 2 were N2b, 1 was N2c and 1 was

N3. After neck exploration with the sentinel node tech-

nique and neck dissection when indicated: 8 patients were

pN0, 7 patients were pN1, 7 patients were pN2 and 2 were

pN3.

None of the patients required tracheotomy and there

were no intraoperative complications related to the use of

the robot. However, we observed three complications in

this series: tongue edema, delirium tremens, cardiac

infarcts. Tongue edema may be due to the pressure on the

tongue by the FK retractor in a patient with a limited mouth

opening and a long duration of surgery.

We used the FK retractor in 18 procedures, the Crow-

Davis retractor for 2 procedures and LARS retractor in 4

procedures.

The mean follow-up time is 17 months. This period is

insufficient for adequate oncologic control data for com-

parison with other treatments. There were two disease-

related deaths because of locoregional recurrence of tumors

of the base of tongue for one patient and mobile tongue for the

other patient. Both had neck dissection at the time of surgery

followed by radiation therapy because of extracapsular

spread. No concomitant chemo-radiation therapy could be

performed in both of the patients because of comorbidities

precluding the administration of chemotherapy.

Time parameters assessed

The time required to complete two discrete stages of the

operation was carefully documented. These stages are: the

installation of the mouth retractor to achieve adequate

exposure and the operative procedure.

Exposure of the surgical field

The mean time required for installation of the mouth

retractor to achieve adequate exposure of the surgical field

was 24 ± 14 min, with a range of 10–60 min.

Duration of the operative segment

The mean overall surgical time was 67 ± 46 min with a

range of 12–180 min.

Overall procedure time

Overall, the mean cumulative time for adequate surgical

field exposure and the operative segment for all operations

was 92 ± 56 min with a range of 22–230 min. Sometimes

the exposure of the tumor took nearly as much time as

removal for the tumor. We also recorded the overall pro-

cedure time for each type of surgery according to the date

of the procedure on the learning curve. The mean total

operative time was 122 ± 63 min for supraglottic laryn-

gectomies, 78 ± 55 min for tonsillectomies, 71 ± 37 min

for partial pharyngectomies and 58 ± 66 min for resection

of oral cavity tumors. For all the procedures, there was a

significant reduction of both the operative segment and the

overall procedure time between the first group of treated

patients (n, 1–12) and the second group of treated patients

(n, 13–24). For the operative segment, time was reduced

from 88 ± 53 to 47 ± 29 min (p = 0.020). For the overall

procedure, time was reduced from 117 ± 64 to 66 ± 33

min (p = 0.014). Moreover, there was a significant corre-

lation between the sequential order of the procedure and

the operative segment time (r = -0572, p = 0.003) or the

overall procedure time (r = -0.590, p = 0.002). How-

ever, the time taken for exposure was not reduced with

experience (Fig. 4).

The mean hospital stay was 9 days (2–50 days). Oral

feeding was resumed at 3 days (1–20 days) under speech

therapy control.

Discussion

The da Vinci system provides some advantages in com-

parison to TLM. It filters out natural hand tremor, adjusts

the large hand movements of the operator to the small

movements of instruments in the airway enhancing dex-

terity and finally it allows a three-dimensional visualization

of the surgical field which gives the surgeon true depth

perception [4]. Taking advantage of these characteristics,

many surgeons are performing transorally, surgeries

that were still performed with an open approach, such

as resection base of tongue of cancer, or supraglottic

laryngectomies, or resection of hypopharyngeal tumors

[5, 8–11].

We did not encounter technical difficulties during the

procedure because all the patients underwent previous

endoscopy under general anesthesia to verify the adequate

exposure with the appropriate retractor. This safe attitude

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123

precluded the necessity to unexpectedly convert a TORS to

an open approach. The first procedures were performed by

the two senior surgeons. At present, one of the senior

surgeon is at the console with one of our fellows or senior

residents as the helping hand. Starting the procedures with

two experimented surgeons is advised. The surgeon at the

head of the patient has an important role for the safety of

the procedure.

If we compare our results to those published in the lit-

erature, we find that the mean total time of transoral robotic

supraglottic laryngectomy in our series (122 min) is com-

parable to the total operating time ranging between 92 and

178 min in the first three patients with supraglottic partial

laryngectomy in the series by Weinstein et al. [5].

For tumor of the tonsils, our mean total operating time

for radical tonsillectomy was 78 min which is concordant

with the findings of Weinstein et al. in a prospective study

on 27 patients undergoing transoral robotic radical tonsil-

lectomy, where the mean overall operative time was 1 h

and 43 min (range 26 min to 3 h 53 min) [10].

For transoral robotic partial pharyngectomy, our mean

operative time of 71 min is concordant with the durations

reported by Park et al. [9].

Despite our new application of TORS, we did not find

any preoperative complications and the use of frozen sec-

tion analysis allowed negative surgical margins for all

patients in a single procedure. Two patients had local

recurrences. Both had T2 tumors, one of the base of tongue

and the other of the mobile tongue. They had negative

margins on frozen section analysis that were confirmed on

routine histological examination. These recurrences can be

due to the absence of the administration of chemotherapy

because of the patients’ co morbidities especially that these

tumors can be multifocal.

For all the procedure, there was a significant reduction

of both the operative segment and the overall surgical time

with improving skills. When we separate the patients into

two groups, the first composed of the first 12 patients and

the second by the 12 last patients, the duration of the

operative segment was reduced by half going from 88 to

46 min. In their study, Moore et al. [11] found that a

reduction in exposure time did not find a reduction of the

operative time as we did. This might be due to the inclusion

of advanced T stages in their series, which are known to

necessitate longer operative time.

Despite all its benefits, there are some limitations

encountered in TORS [16]:

1. Interference of the surgical arms with one another,

with the camera arm, or with the retractor during the

operation.

2. Thermal effects with monocautery leading to more

crusting.

3. Lack of tactile feedback recognition and proprioception.

4. The absence of integrated aspiration.

Solutions might be found.

The interference of the surgical arms with one another

and with the camera arm is due to the narrow operative

area and to the large size of the surgical arms. It sometimes

requires manual repositioning of the robotic instruments

and the camera. A slight increase in the distance between

the camera port and the instrument port might result in the

reduction in the frequency of the interference. The use of

the appropriate retractor is also of primary importance to

enlarge the operative view. Hockstein and colleagues [17]

reported the use of the Dingman mouth gag for airway

surgery on a mannequin and cadavers. The Dingman mouth

gag with cheek retractors achieved satisfactory exposure,

unimpeded instrument movement, precise handling of tis-

sue, and an ability to perform endolaryngeal suturing.

Weinstein et al. [5] reported the use of the FK retractor for

supraglottic partial laryngectomy and Crow-Davis mouth

gag for radical tonsillectomy [10]. Park et al. [9] used the

FK retractor for hypopharyngeal tumors.

We find that the use of the FK retractor with an addi-

tional cheek protector is valuable. However, in some cases,

the surgical exposure proved to be difficult [18], even with

the FK retractor, this is why a new retractor was introduced

by the authors.

The thermal effects of the monocautery will be reduced

in the future by the use of the CO2 laser wave guide.

Tactile feedback is considered very valuable in surgery;

however, the three-dimensional images with the da Vinci

system compensate for the diminished tactile information.

There is also a visual adaptation.

The current da Vinci robot lacks an integrated suction

device. To resolve this problem, Weinstein et al. [5]

attached an endotracheal suction to a robotic arm. Suc-

tioning might be done through a flexible nasopharyngeal

Fig. 4 Operative segment and overall procedure time depending on

the sequential order of the surgical procedure in the learning curve (y-axis time in minutes, x-axis rank of surgery during the learning curve)

1800 Eur Arch Otorhinolaryngol (2011) 268:1795–1801

123

tube and if additional suctioning is needed, it might be

provided by a rigid suction tube handled by the assistant or

fixed on the framework of the LARS retractor.

Conclusion

TORS is feasible, safe, oncologically and functionally

efficacious. It has a short learning curve for surgeons

already trained in transoral surgery. It facilitates the

exposure of surgical sites like the supraglottis, the base of

tongue and the piriform sinuses. It is a valuable technique,

and we are convinced that it will have many applications in

the future in the field of head and neck surgery.

The new LARS retractor and the CO2 wave guide are

new contributions to TORS and provide solutions to lim-

iting factors for the application of TORS in some transoral

procedures.

Acknowledgments The authors would like to thank Mrs M.-B.

Jacqmain for the illustrations.

Conflict of interest None.

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