Robotic Approaches to the Pharynx




Treatment of squamous cell carcinoma of the oropharynx is challenging because of its effects on speech and swallowing, which may affect quality of life. Transoral robotic surgery may be an effective alternative to open surgery. Robotic lateral oropharyngectomy is best suited for early stage oropharyngeal squamous cell carcinoma, with the goal of avoiding or reducing the use or dose of adjuvant therapies. Successful robotic lateral oropharyngectomy requires appropriate training, detailed preoperative planning, organized operating room setup to obtain exposure, an understanding of the pertinent surgical anatomy, and knowledge of the postoperative care of the oncologic patient.


Key points








  • Transoral robotic surgery (TORS) for tonsil cancer is an effective alternative to open surgery.



  • Robotic lateral oropharyngectomy requires thorough understanding of oropharyngeal internal, parapharyngeal, and vascular anatomy.



  • Preliminary reports have shown similar oncologic outcomes compared with historical surgical and nonsurgical treatments.



  • The functional results of TORS compared with open surgical approaches show a decreased rate of permanent gastrostomy and tracheostomy tube dependence.




Videos of transoral robotic surgery (TORS) accompany this article at http://www.oto.theclinics.com/




Introduction


It was estimated that 41,380 individuals (29,620 men and 11,760 women) would be diagnosed with and 7890 men and women would die of squamous cell carcinoma (SCC) of the oral cavity and pharynx in 2013. Although the overall incidence of oral cavity and oropharynx SCC has been decreasing by approximately 1% per year, the incidence continues to increase in younger patients, because of the increasing incidence of human papillomavirus (HPV)-associated oropharyngeal SCC. Treatment of oropharyngeal SCC is particularly challenging, because this site is involved in the crucial functions of breathing, deglutition, and speech. Impairment of any of these functions may significantly affect quality of life. Thus, both oncologic and functional outcomes are important considerations in the treatment of oropharyngeal SCC, including cancers that involve the tonsil.


Traditional treatment of oropharyngeal cancers centered on surgical resection, which was often associated with significant morbidity. Several surgical options are available, with different exposures and associated morbidities. Mandibulotomy or mandibulectomy allow broad access to the oropharynx, but complication rates range from 10% to 60% and include difficulty with speech and swallowing, malocclusion, temporomandibular joint pain, and cosmetic deformity. Lateral pharyngotomy, transhyoid pharyngotomy, or suprahyoid pharyngotomy may be used as an alternative to mandible splitting procedures. Patients undergoing pharyngotomy are at increased risk of pharyngocutaneous fistula formation and severe dysphagia, which has been reported to occur in 7% to 38% of patients. Transoral resection provides the most direct route to the oropharynx, with the potential for decreased morbidity. The primary disadvantage of the transoral approach can be related to exposure, because of the need for direct line of sight. Many tonsil and pharyngeal cancers are difficult or impossible to reach through the mouth under direct vision. Acceptable oncologic outcomes have been reported using each of these approaches in selected patients ( Table 1 ).



Table 1

Outcomes of traditional surgical approaches to the oropharynx






































































































Study Patients
T Stage
Human Papillomavirus+ Tumor Site(s) Primary Treatment Modality Overall Survival (%) Temporary/Permanent Tracheostomy (%) Temporary/Permanent Gastrostomy Tube (%)
1 y 1.5 y 2 y >
Sydney Head and Neck Cancer Institute 92 NR T1,2
OP
Surgery 83 (5 y)
Hôpital de la Croix-Rousse 53 NR T1,2
OP
Surgery 100 73 (5 y)
University of Paris 191 NR OP Surgery 88 58 (5 y) 3.7/0 58.6/0
Mayo Clinic 102 NR OP Surgery 92 85 (5 y) 34/4 14/1
University of Florida 490 NR OP XRT 44 (5 y)
MD Anderson Cancer Center 150 NR OP XRT 47 (5 y)
Total 1078 55 18/2 36/1

Abbreviations: NR, not reported; OP, oropharynx; XRT, radiotherapy.

Data from Refs.


Because of the difficult of exposure and potential for surgery-related morbidity, the treatment of oropharyngeal SCC in recent decades has evolved to a primary nonsurgical approach, namely chemoradiation. The Veterans Affairs study in 1991 heralded an era of organ preservation strategies, which have since been extrapolated from the larynx to the oropharynx. However, surgical approaches and techniques in head and neck cancer surgery have evolved dramatically. There is increased attention to functional preservation and use of minimally invasive procedures wherever feasible without compromising oncologic outcomes. Less radical procedures with minimal collateral tissue damage are preferred to decrease postoperative complications and to improve quality of life.


Several studies have shown that transoral robotic surgery (TORS) may be an effective alternative to open surgery. The high-resolution, magnified, three-dimensional view of the operative field provided by TORS allows for excellent visualization of the target anatomy. TORS may overcome some limitations in exposure of surgical anatomy inherent in the direct line of site approach used in transoral laser microsurgery with its use of angled binocular endoscopic visualization. Additional advantages of TORS may include improved cosmesis, decreased length of hospital stay, and a low rate of gastrostomy tube dependence, improved long-term preservation of swallowing function, and ability to deintensify adjuvant therapy ( Table 2 ). High rates of negative surgical margins have been reported, which correlate well with local disease control ( Table 3 ).



Table 2

Transoral robotic surgery functional outcomes



































































Study a Patients Tumor Site(s)
T Stage
Temporary/Permanent Tracheostomy (%) Oral Diet Only Within 6 wk (%) Temporary/Permanent Gastrostomy Tube (%) Preoperative/1 mo After MDADI Baseline/3 mo/12 mo HNQOL
University of Pennsylvania 47 OP
T 1–4
11/0 0/2
University of Alabama 89 OC, OP, L
T 1–4
3/0 79 25/0 77/61
Mount Sinai Medical Center 30 OP, L
T 1–2
13/0 76.3/61.2/76.8
Mayo Clinic 66 OP
T 1–3
26/2 97 27/5
Ohio State University 81 OP
T 1–3
100 21/9 78.7/67.9/77.9
Total 313 13/1 92 18/4

Abbreviations: HNQOL, Head and Neck Quality of Life instrument; L, larynx; MDADI, MD Anderson Dysphagia Inventory; OC, oral cavity; OP, oropharynx.

Data from Refs.

a Consecutive institutional studies summarized. Maximum number of study patients cited.



Table 3

Transoral robotic surgery oncologic outcomes
























































































































Study Patients
T Stage
Human Papillomavirus+ Overall Survival (%) Disease-Specific Survival (%) Recurrence-Free Survival (%)
1 y 1.5 y 2 y > 1 y 1.5 y 2 y > 1 y 1.5 y 2 y >
University of Alabama 89
T 1–4
89 86
University of Pennsylvania 50
T 1–4
74 96 81 98 93
Mount Sinai Medical Center 30
T 1–2
90 78
Ohio State University 66
T 1–3
67 96 (3 y) 95 (3 y) 92 (3 y)
Mayo Clinic 81
T 1–3
72 92 89 (4 y)
Total 316 71

Data from Refs.




Introduction


It was estimated that 41,380 individuals (29,620 men and 11,760 women) would be diagnosed with and 7890 men and women would die of squamous cell carcinoma (SCC) of the oral cavity and pharynx in 2013. Although the overall incidence of oral cavity and oropharynx SCC has been decreasing by approximately 1% per year, the incidence continues to increase in younger patients, because of the increasing incidence of human papillomavirus (HPV)-associated oropharyngeal SCC. Treatment of oropharyngeal SCC is particularly challenging, because this site is involved in the crucial functions of breathing, deglutition, and speech. Impairment of any of these functions may significantly affect quality of life. Thus, both oncologic and functional outcomes are important considerations in the treatment of oropharyngeal SCC, including cancers that involve the tonsil.


Traditional treatment of oropharyngeal cancers centered on surgical resection, which was often associated with significant morbidity. Several surgical options are available, with different exposures and associated morbidities. Mandibulotomy or mandibulectomy allow broad access to the oropharynx, but complication rates range from 10% to 60% and include difficulty with speech and swallowing, malocclusion, temporomandibular joint pain, and cosmetic deformity. Lateral pharyngotomy, transhyoid pharyngotomy, or suprahyoid pharyngotomy may be used as an alternative to mandible splitting procedures. Patients undergoing pharyngotomy are at increased risk of pharyngocutaneous fistula formation and severe dysphagia, which has been reported to occur in 7% to 38% of patients. Transoral resection provides the most direct route to the oropharynx, with the potential for decreased morbidity. The primary disadvantage of the transoral approach can be related to exposure, because of the need for direct line of sight. Many tonsil and pharyngeal cancers are difficult or impossible to reach through the mouth under direct vision. Acceptable oncologic outcomes have been reported using each of these approaches in selected patients ( Table 1 ).



Table 1

Outcomes of traditional surgical approaches to the oropharynx






































































































Study Patients
T Stage
Human Papillomavirus+ Tumor Site(s) Primary Treatment Modality Overall Survival (%) Temporary/Permanent Tracheostomy (%) Temporary/Permanent Gastrostomy Tube (%)
1 y 1.5 y 2 y >
Sydney Head and Neck Cancer Institute 92 NR T1,2
OP
Surgery 83 (5 y)
Hôpital de la Croix-Rousse 53 NR T1,2
OP
Surgery 100 73 (5 y)
University of Paris 191 NR OP Surgery 88 58 (5 y) 3.7/0 58.6/0
Mayo Clinic 102 NR OP Surgery 92 85 (5 y) 34/4 14/1
University of Florida 490 NR OP XRT 44 (5 y)
MD Anderson Cancer Center 150 NR OP XRT 47 (5 y)
Total 1078 55 18/2 36/1

Abbreviations: NR, not reported; OP, oropharynx; XRT, radiotherapy.

Data from Refs.


Because of the difficult of exposure and potential for surgery-related morbidity, the treatment of oropharyngeal SCC in recent decades has evolved to a primary nonsurgical approach, namely chemoradiation. The Veterans Affairs study in 1991 heralded an era of organ preservation strategies, which have since been extrapolated from the larynx to the oropharynx. However, surgical approaches and techniques in head and neck cancer surgery have evolved dramatically. There is increased attention to functional preservation and use of minimally invasive procedures wherever feasible without compromising oncologic outcomes. Less radical procedures with minimal collateral tissue damage are preferred to decrease postoperative complications and to improve quality of life.


Several studies have shown that transoral robotic surgery (TORS) may be an effective alternative to open surgery. The high-resolution, magnified, three-dimensional view of the operative field provided by TORS allows for excellent visualization of the target anatomy. TORS may overcome some limitations in exposure of surgical anatomy inherent in the direct line of site approach used in transoral laser microsurgery with its use of angled binocular endoscopic visualization. Additional advantages of TORS may include improved cosmesis, decreased length of hospital stay, and a low rate of gastrostomy tube dependence, improved long-term preservation of swallowing function, and ability to deintensify adjuvant therapy ( Table 2 ). High rates of negative surgical margins have been reported, which correlate well with local disease control ( Table 3 ).


Apr 1, 2017 | Posted by in OTOLARYNGOLOGY | Comments Off on Robotic Approaches to the Pharynx

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