Keywords nasopharyngeal stenosis - robotic-assisted surgery - Da Vinci Xi - robot endoscopic
surgery - transoral robotic surgery (TORS) - skull base surgery - nasal endoscope
- mitomycin C - ENT surgery - head and neck surgery
Introduction
Nasopharyngeal stenosis is commonly iatrogenic and is the result of procedures performed
in or around the nasopharynx which can include surgery and radiation therapy. It can
also be the sequela of infectious disease such as diphtheria, rhinoscleroma, tuberculosis,
and syphilis.[1 ] The symptoms of nasopharyngeal stenosis usually include dysphagia, hyponasal speech,
nasal obstruction, and difficulty sleeping.
In prior nasopharyngeal stenosis repairs, various surgical techniques have been employed.
Each has its own advantages and limitations depending on the severity and etiology
of the stenosis. Traditional approaches have included the use of mucosal flaps, such
as the laterally based pharyngeal flap, and the transposition of local tissue flaps
to restore nasopharyngeal patency.[1 ] For example, to address both nasopharyngeal stenosis and tonsillar pillar adhesions
in a single-stage operation, a palatal eversion technique could be employed where
the soft palate is divided and repositioned to separate scarred tissue.[2 ] This approach was particularly useful in cases of post-adenotonsillectomy scarring
where fibrosis caused significant airway obstruction. Similarly, another case described
the excision of dense, avascular fibrotic tissue, followed by reconstruction using
split-thickness skin grafts to prevent re-stenosis.[1 ] Although these techniques have demonstrated efficacy, challenges such as restenosis,
scarring, and incomplete resolution remain, necessitating innovative approaches like
the dual robotic and endonasal method described in this report.
We present the case of a patient with severe nasopharyngeal stenosis caused by the
use of hydrogen peroxide irrigations which he had been doing for approximately 2 years
following functional endoscopic sinus surgery (FESS) for chronic sinus disease. A
combined transoral and transnasal surgical approach with a robotically trained head
and neck surgeon and rhinologist was devised to improve field visualization and surgical
maneuverability.
The Da Vinci surgical robot has progressively translated its applications in general
surgery, urology, gynecology, cardiothoracic, pediatrics, and ENT surgery. The surgical
system has four EndoWrist robotic arms that offer enhanced manual dexterity and a
three-dimensional magnified image for improved visualization.[3 ]
[4 ] Traditional transoral approaches to the oropharynx have several existing limitations.
Specifically, there is a confined operative field, limited range of instrument motion,
and optical concerns such as reduced line of sight and depth perception. Other areas
of ENT surgery including endoscopic thyroid and parathyroid also have inherent limitations
such as video camera platform instability, restricted motion of straight endoscopic
instruments, two-dimensional imaging, and suboptimal operator ergonomics.[5 ] Applications of the Da Vinci robot as well as combined surgical technologies may
prove to solve these issues in the future upon further development and integration.
Nasopharyngeal Stenosis Classifications
Nasopharyngeal Stenosis Classifications
Nasopharyngeal stenosis can be categorized into types I, II, and III, with each having
different degrees of severity. Type I is a mild grade where the lateral aspects of
the palate adhere to the posterior pharyngeal wall. Type II is a moderate grade characterized
by circumferential scarring, resulting in a small central opening of the soft palate
measuring 1 to 2 cm in diameter. Type III is a severe grade identified by the complete
fusion of the entire palate with the posterior and lateral palatal wall, leaving a
residual opening of less than 1 cm.[6 ]
Case Presentation
A 67-year-old male presented with nasal congestion, frequent, thick mucus drainage,
and sores in his nostrils. He had a history of chronic sinus disease and had undergone
balloon sinuplasty at an outside institution, as well as two other surgeries in the
past to help manage it. He was then instructed to use hydrogen peroxide sinus rinses,
which was a regimen he continued for approximately 2 years. This ultimately led to
the stenosis of his nasopharynx.
Despite previous surgical interventions including an FESS, the patient's symptoms
worsened over time, particularly the nasal obstruction, sores, and drainage, none
of which improved with antibiotic treatments. Imaging studies showed that while CT
scans demonstrated some improvement from the earlier surgeries, an MRI revealed a
Tornwaldt cyst, mucosal thickening in the left nasopharynx, and bilateral maxillary
and ethmoid thickening.
During a follow-up visit, the patient reported that his nasal obstruction was progressively
worsening. In-office nasal and oral endoscopy ([Fig. 1A, B ]) revealed type II nasopharyngeal stenosis, likely resulting from prolonged hydrogen
peroxide irrigation. Based on these findings, further surgical intervention was deemed
necessary to address the stenosis and restore airway patency ([Fig. 2A, B ]).
Fig. 1 (A) Preoperative oral view of the enclosed nasopharynx using the endoscope. (B) Preoperative
endonasal view of the enclosed nasopharynx using the endoscope.
Fig. 2 (A) Endonasal view of the nasopharynx after it had been opened up by the robot. (B)
Oral view from the Point of view of the robot as it applies topical mitomycin C.
Surgical Procedure
To improve visualization of the surgical field and surgical dexterity, the senior
authors employed a novel approach, utilizing both the Da Vinci Xi robot (with a 30-degree
endoscope) and a 70-degree nasal endoscope. The surgical robot was equipped with Maryland
bipolar forceps and a cautery spatula. The robotic surgeon was positioned at the robot
console while the endonasal surgeon was positioned at the head of the operating room
table; the latter acting as the assistant for the transoral robotic surgeon while
visualizing the nasopharynx from above. This setup was employed to view the nasopharynx
and soft palate from both inferior and superior simultaneously. The room setup is
demonstrated in [Fig. 3A, B ].
Fig. 3 (A) A real photo of surgical setup showcasing the intricate surgical setup during
the nasopharyngeal stenosis repair procedure. The image captures the simultaneous
utilization of the Da Vinci Xi robot and a reverse-posted nasal endoscope. (B) Animated
diagram of an aerial view of the operating room (OR) setup offering a better visual
representation of where the equipment and surgeons were strategically positioned.
The surgery began with the robot incising the scar band present between the soft palate
and posterior pharyngeal wall in the oropharynx. Once the soft palate had been released,
the upper limit of the field of view of the surgical robot was reached. Further division
of scar tissue was performed from inferior to superior along the posterior pharyngeal
wall using the robotic instruments under the guidance of the endonasal surgeon who
was visualizing the nasopharynx from above. Dissection continued from medial to lateral
on both sides to recreate the fossa of Rosenmuller that had been scarred due to hydrogen
peroxide irrigations ([Fig. 2A ]). Once the soft tissue dissection was complete, mitomycin C was applied topically
to the raw edges of the field to aid in preventing scar reformation postoperatively
([Fig. 2B ]). Two nasal trumpets were placed into the nasal cavity and through the stenosis
site to retain airway patency in recovery and were sewn to the nasal septum.
Postoperative Course
In the days following the surgery, the patient utilized nasal saline sprays as prescribed.
On postoperative day 8, the patient presented with intolerance of the nasal trumpets
and these were removed without incident. He continued to use the nasal saline spray
once the trumpets were removed.
At 3 weeks into his recovery, the patient reported a substantial improvement in nasal
breathing with no nasal regurgitation of solids or liquids. His speech was mildly
hypernasal but the patient did not report any difficulty with speech intelligibility.
Diagnostic nasal endoscopy revealed an expanded nasopharyngeal opening and minimal
excess scarring, signifying effective healing ([Fig. 4A ]).
Fig. 4 (A) Nasal endoscopic view of the opened and healing nasopharynx at 3 weeks following
surgery. (B) Nasal endoscopic view of the opened nasopharynx at 1 year following surgery.
At 1 year following his surgery, nasal endoscopy shows a maintained opening of the
nasopharynx with minimal scarring ([Fig. 4B ]).
Discussion
The utilization of a dual approach combining the Da Vinci Xi robot and the nasal endoscope
in nasopharyngeal stenosis repair represents a pioneering advancement in the field
of robotic-assisted surgery. This novel combination offers a multitude of benefits
that synergistically enhances the surgeons' capabilities, improves visualization,
and increases precision during the surgical procedure.
One of the major advantages of this dual approach is the ability to access and navigate
small and challenging anatomical spaces with greater ease as seen in [Fig. 5A, B ]. The Da Vinci Xi robotic arms equipped with EndoWrist instruments provide the surgeon
with enhanced dexterity and a wider range of motion, allowing delicate maneuvers within
confined areas of the nasopharynx.[7 ] The nasal endoscope further complements these capabilities by providing top-down
visualization of the surgical site, especially in areas such as the nasopharynx that
are difficult to visualize with the robotic endoscope when it is positioned in the
oral cavity. The integration of these technologies facilitates improved maneuverability,
granting the surgeons greater control and finesse in navigating intricate anatomical
structures utilizing the robotic instruments while having a 360-degree view of the
surgical field. Alone, neither the transoral robotic nor endonasal approach to nasopharyngeal
stenosis can accomplish this.
Fig. 5 (A) Oral view of the nasopharynx from the point of view of the robot during the operation.
Note the difficult angle and view of the opening. Labels ‘L’ and ‘R’ indicate the
left and right sides of the surgical field, respectively, for orientation. (B) Endonasal
view of the opened nasopharynx from the point of view of the endoscope during the
operation. Note the much clearer view of both the opening and walls of the nasopharynx.
Moreover, this dual approach has the potential to lead to improved surgical outcomes
for future procedures. The enhanced visualization, precision, and maneuverability
offered by both the robot and the endoscope may contribute to reduced surgical complications,
preservation of vital structures, and overall patient safety. The successful application
of this dual approach in nasopharyngeal stenosis repair opens the door to expanding
applications in robotic-assisted surgeries. As surgeons gain experience and expertise
with this novel technique, its potential may extend to other complex anatomical regions
and surgical procedures. The combination of different surgical technologies may also
inspire further research and innovation, leading to the development of new approaches
and protocols for various medical conditions.
Conclusion
This case report highlights an innovative combination of surgical approaches utilizing
the Da Vinci Xi robot and a nasal endoscope in nasopharyngeal stenosis repair, offering
improved visualization and surgical precision. This innovative technique not only
benefits current patients by improving outcomes but also opens avenues for future
advancements and expansion of applications in robotic-assisted surgical interventions
for nasopharyngeal and skull base surgery. Continued research and exploration of this
dual approach are critical to unlock its full potential and shape the future landscape
of surgical practices.
