Soft robotic manipulator for intraoperative MRI-guided transoral laser microsurgery.

Magnetic resonance (MR) imaging (MRI) provides compelling features for the guidance of interventional procedures, including high-contrast soft tissue imaging, detailed visualization of physiological changes, and thermometry. Laser-based tumor ablation stands to benefit greatly from MRI guidance because 3D resection margins alongside thermal distributions can be evaluated in real time to protect critical structures while ensuring adequate resection margins. However, few studies have investigated the use of projection-based lasers like those for transoral laser microsurgery, potentially because dexterous laser steering is required at the ablation site, raising substantial challenges in the confined MRI bore and its strong magnetic field. Here, we propose an MR-safe soft robotic system for MRI-guided transoral laser microsurgery. Owing to its miniature size (Ø12 × 100 mm), inherent compliance, and five degrees of freedom, the soft robot ensures zero electromagnetic interference with MRI and enables safe and dexterous operation within the confined oral and pharyngeal cavities. The laser manipulator is rapidly fabricated with hybrid soft and hard structures and is powered by microvolume (<0.004 milliter) fluid flow to enable laser steering with enhanced stiffness and lowered hysteresis. A learning-based controller accommodates the inherent nonlinear robot actuation, which was validated with laser path-following tests. Submillimeter laser steering accuracy was demonstrated with a mean error < 0.20 mm. MRI compatibility testing demonstrated zero observable image artifacts during robot operation. Ex vivo tissue ablation and a cadaveric head-and-neck trial were carried out under MRI, where we employed MR thermometry to monitor the tissue ablation margin and thermal diffusion intraoperatively.

Endoscopic Transoral Hybrid Supracricoid Partial Laryngectomy with Cricohyoidoepiglottopexy.

OBJECTIVES: The hybrid supracricoid partial laryngectomy with cricohyoidoepiglottopexy (SCPL-CHEP, that is, open partial horizontal laryngectomies OPHL Type IIa) has been described using a flexible next generation robotic surgical platform for manipulation. We sought to evaluate the feasibility of performing this procedure using endoscopic transoral (EndoT) surgical techniques without robotics. METHODS: Preclinical cadaveric study using two human cadavers. Hybrid SCPL-CHEP was performed with a flexible endoscope for visualization and hand-held instruments for manipulation (SILS Hook monopolar and Dissect, HAVAS LaryngoFIT malleable straight jaw instruments, and Stratafix 4-0 spiral knotless barbed suture). RESULTS: EndoT hybrid SCPL-CHEP was successfully performed. The hand-manipulated rigid instruments allowed for transoral incisions and mucosal suturing. We provide the procedural steps of EndoT hybrid techniques. CONCLUSIONS: EndoT hybrid SCPL-CHEP was technically feasible in the preclinical cadaveric laboratory setting and appeared comparable to the hybrid SCPL-CHEP via transoral robotic surgery (TORS). Selected handheld instruments and flexible endoscopy appear to facilitate minimally invasive surgery of the larynx. This novel procedure and technique warrant further clinical study for consideration of feasibility, applicability, and patient benefit.

A Next-Generation Single-Port Robotic Surgical System for Transoral Robotic Surgery: Results From Prospective Nonrandomized Clinical Trials.

IMPORTANCE: Transoral endoscopic head and neck surgery now plays an important role in the multidisciplinary management of oropharyngeal carcinoma. Previous generations of robotic surgical systems used a multiport system with a rigid stereo-endoscope and 2 wristed instruments that facilitated transoral robotic surgery. OBJECTIVE: To evaluate a new single-port robotic surgical system in head and neck surgery prospectively through concurrent nonrandomized clinical trials. DESIGN, SETTING, AND PARTICIPANTS: Two prospective clinical trials were conducted from December 16, 2016, to December 26, 2017, to assess the safety, feasibility, and performance of a flexible single-port robotic surgical system in 4 institutions, including 3 in the United States and 1 in Hong Kong. A total of 47 patients with tumors of the oropharynx were enrolled and underwent surgery. All patients were classified as having American Society of Anesthesiologists class I to III status and Eastern Cooperative Oncology Group status 0 to 1. An initial cohort of 7 patients underwent staging and endoscopic procedures for benign disease. The remaining 40 patients all had malignant tumors of the oropharynx. MAIN OUTCOMES AND MEASURES: Safety was measured by the incidence of device-related serious adverse events. Feasibility and performance were measured by the conversion rate from the use of the single-port robotic surgical system to either open surgery or the use of any other transoral technology required to complete the planned procedure. Secondary end points of swallowing function and surgical margins were also measured. RESULTS: All 47 patients (8 women and 39 men; mean [SD] age, 61 [8] years) safely underwent transoral resection with the single-port robotic surgical system without conversion to open surgery, laser surgery, or multiport robotic surgery. There were no intraoperative complications or device-related serious adverse events. Mean (SD) estimated intraoperative blood loss per procedure was 15.4 (23.9) mL; no patients received a transfusion. Two patients underwent a planned tracheotomy owing to medical comorbidity (previous chemoradiotherapy; obesity and severe sleep apnea). Two patients (4%) had grade III or IV postoperative hemorrhage, requiring a return to the operating room; however, both patients had medical comorbidities requiring the use of antithrombotic medication. The incidence of positive margins for patients with oropharyngeal malignancy was 3% (1 of 40). Within 30 days, 45 patients (96%) were eating by mouth and without the need for a percutaneous endoscopic gastrostomy tube. CONCLUSIONS AND RELEVANCE: This study describes the results of phase 2 clinical testing of a next-generation, robotic surgical system using a single-port architecture. The use of the device appears to be feasible, safe, and effective for transoral robotic surgery of oropharyngeal tumors. TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT03010813 and NCT03049280.

Maxillary osteosarcoma associated with a dental implant: report of a case and review of the literature regarding implant-related sarcomas.

BACKGROUND: The development of malignant neoplasms has been reported as a rare complication of the use of implanted biomaterials. The majority of these cases have been sarcomas related to orthopedic hardware. The authors present the first reported case of a sarcoma arising in association with a dental implant. CASE DESCRIPTION: A 38-year-old woman developed a low-grade chondroblastic osteosarcoma of the right maxilla 11 months after receiving a titanium dental implant. She was treated with systemic chemotherapy and then a maxillary resection. As of this publication, 47 months later, she is alive and disease-free. CLINICAL IMPLICATIONS: The use of endosseous implants has been associated with a low risk for the development of cancer. As the use of dental implants continues to expand, dentists need to be aware of this rare but devastating complication.

Concordance of oral HPV prevalence between patients with oropharyngeal cancer and their partners.

BACKGROUND: Human papilloma virus (HPV) is a known causative factor in oropharyngeal squamous cell cancer (OPC). In this prospective study, we sought to define the risk of HPV transmission between OPC patients and their sexual partners by performing HPV genotyping on oral cytology brushings. METHODS: Newly diagnosed OPC patients and their sexual partners underwent oral mouth swabs and answered a risk factor questionnaire. Patient tumor samples and oral swabs from both the patient and partner were assessed for HPV status and genotyped using Easy-Chip HPV Blot PCR. RESULTS: We enrolled 227 patient-partner pairs and obtained sufficient analyzable DNA from both members in 198 pairs. Of 144 patients with available OPC tumor tissue, 128 (89 %) had HPV-positive tumors by either in situ hybridization or p16 immunohistochemical analysis (104 or 121, respectively). In total, there were 28 patients and 30 partners who were HPV positive by oral swab. The prevalence rate of oral HPV in partners was 15 %. There were 39 patient-partner pairs who had one or both members returning positive for HPV in the oral swab, and 49 % of these pairs were concordant for their HPV-genotype. Female partners had a higher oral HPV prevalence (16 %) than did male partners (11 %). Patients who were non-white were also found to have a higher oral prevalence of HPV (p = 0.032) by mouth swab. CONCLUSIONS: Partners of OPC patients may have a higher prevalence of oral HPV and should be studied prospectively to understand their OPC risk. Additional future research is needed to identify oral HPV persistence in partners to OPC patients and to determine the optimal sampling methods and technologies to screen patients at high risk for HPV-related disease.

Transoral Endoscopic Head and Neck Surgery and Its Role Within the Multidisciplinary Treatment Paradigm of Oropharynx Cancer: Robotics, Lasers, and Clinical Trials.

Transoral endoscopic head and neck surgery is a new approach for the treatment of oropharyngeal tumors. Using either a robotic system and/or laser, surgeons gain access through the mouth via minimally invasive technique and thus have improved visualization of the tumors of the oropharynx, without disfiguring incisions. This transoral route of access minimizes long-term speech and swallowing dysfunction. Surgeons view this approach as a considerable technologic advance, analogous to the evolution in radiation therapy from conventional two- and three-dimensional conformal techniques to intensity-modulated techniques. Although the use of radiation with or without chemotherapy to treat oropharyngeal cancer (OPC) is supported by evidence from prospective clinical trials, there are no prospective data supporting the use of this new surgical approach for OPC. Here, we review the fundamentals of transoral endoscopic head and neck surgery, with robotics and laser technology, and discuss ongoing clinical trials for patients with OPC.

Detection of plasminogen activators in oral cancer by laser capture microdissection combined with zymography.

Plasminogen activation is believed to be critical to the progression of oral squamous cell carcinoma by facilitating matrix degradation during invasion and metastasis, and high levels of urokinase plasminogen activator (uPA) and plasminogen activator (PA) inhibitor-1 (PAI-1) in tumors predict poor disease outcome. We describe the development of a novel method for studying PA in oral cancer that combines the sensitivity and specificity of zymography with the spatial resolution of immunohistochemistry. Laser capture microdissection (LCM) was combined with plasminogen-casein zymography to analyze uPA, tissue PA (tPA), uPA-PAI-1 complexes, and tPA-PAI-1 complexes in 11 tumors and adjacent non-malignant epithelium from squamous cell carcinomas of the tongue, floor of mouth, larynx, and vocal cord. uPA was detectable in all tumor samples analyzed, uPA-PAI-1 complexes in three samples, and tPA in nine. PA was detectable in as little as 0.5 microg protein lysate from microdissected tumors. In all specimens, uPA expression was highly increased in tumor tissue compared to adjacent non-malignant tissue. In conclusion, LCM combined with zymography may be excellently suited for analyzing the prognostic significance and causal involvement of the plasminogen activation system in oral cancer.

Osteosarcoma of the jaw in children and young adults.

BACKGROUND: Pediatric jaw osteosarcoma is uncommon, and data are scarce regarding clinical presentation, prognostic factors, and outcome. METHODS: A single-institution medical record review from 1983 to 2008 for 12 patients age ≤ 21 years was undertaken for this study. RESULTS: Median diagnosis age was 16.3 years (range, 6.3-21.9). Nine patients had mandible tumors. Osteoblastic subtype was most common (4 patients). Most tumors were large (ie, T2; n = 8) and high-grade (n = 8). Treatment characteristics were varied. Median follow-up was 27.1 months (range, 8-252 months). Five patients had tumor necrosis <80% after chemotherapy. No deaths were observed. CONCLUSION: Jaw osteosarcoma outcome is better compared to extremity osteosarcoma, but further study is required regarding clinical prognostic factors.

Transoral resection of pharyngeal cancer: summary of a National Cancer Institute Head and Neck Cancer Steering Committee Clinical Trials Planning Meeting, November 6-7, 2011, Arlington, Virginia.

Recent advances now permit resection of many pharyngeal tumors through the open mouth, an approach that can greatly reduce the morbidity of surgical exposure. These transoral techniques are being rapidly adopted by the surgical community and hold considerable promise. On November 6-7, 2011, the National Cancer Institute sponsored a Clinical Trials Planning Meeting to address how to further investigate the use of transoral surgery, both in the good prognosis human papillomavirus (HPV)-initiated oropharyngeal cancers, and in those with HPV-unrelated disease. The proceedings of this meeting are summarized.

Transoral robotic-assisted thyroidectomy with central neck dissection: preclinical cadaver feasibility study and proposed surgical technique.

UNLABELLED: Recently, a transoral robotic-assisted technique to access the thyroid gland has been introduced. Despite the advantages this approach may have over other minimally invasive and robotic-assisted techniques, we found that the placement of the camera through the floor of mouth led to restricted freedom of movement. We describe our modification to this technique to overcome this problem. In a study using two fresh human cadavers, the camera port of the da Vinci robot was placed in the midline oral vestibule instead of the floor of the mouth. A transoral thyroidectomy and central neck dissection was successfully performed. Our modification led to an unfettered view of the central neck and allowed for a total thyroidectomy and central neck dissection. Our modification of transoral robotic-assisted thyroidectomy provides superior access to the central compartment of the neck over other robotic-assisted thyroidectomy techniques. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11701-011-0287-2) contains supplementary material, which is available to authorized users.

Differential diagnosis of pediatric tumors of the nasal cavity and paranasal sinuses: a 45-year multi-institutional review.

We conducted a retrospective case-series review to identify the various diagnoses of neoplasms of the nasal cavity and paranasal sinuses in a pediatric population. Our study group was made up of 54 children-23 boys and 31 girls, aged 8 months to 16 years (mean: 9 yr). All patients had been diagnosed with a tumor of the nasal cavity or paranasal sinuses between Jan. 1, 1955, and Dec. 31, 1999, at one of four university-based, tertiary care referral centers. We compiled data on tumoral characteristics (location, size, and histopathology), morbidity and mortality, and rates of recurrence. Lesions included adnexal neoplasm, ameloblastic fibro-odontoma, basal cell carcinoma, benign fibrous histiocytoma, blue nevus, chondrosarcoma, compound nevus, epithelioma adenoides cysticum, esthesioneuroblastoma, Ewing sarcoma, fibrosarcoma, giant cell granuloma, granulocytic sarcoma, hemangioma, hemangiopericytoma, Langerhans cell histiocytosis, lymphangioma, lymphoma, melanoma, neuroblastoma, neurofibroma, ossifying osteofibroma, osteochondroma, osteosarcoma, port wine stain, rhabdomyosarcoma, Spitz nevus, and xanthogranuloma. To the best of our knowledge, this is the largest such study of its kind to date. We believe that the large size of this study and the data on disease incidence will allow clinicians to be better informed of the differential diagnosis of neoplasms of the nasal cavity and paranasal sinuses in the pediatric population.

The effect of dental artifacts, contrast media, and experience on interobserver contouring variations in head and neck anatomy.

OBJECTIVES: To investigate interobserver variability in the delineation of head-and-neck (H&N) anatomic structures on CT images, including the effects of image artifacts and observer experience. METHODS: Nine observers (7 radiation oncologists, 1 surgeon, and 1 physician assistant) with varying levels of H&N delineation experience independently contoured H&N gross tumor volumes and critical structures on radiation therapy treatment planning CT images alongside reference diagnostic CT images for 4 patients with oropharynx cancer. Image artifacts from dental fillings partially obstructed 3 images. Differences in the structure volumes, center-of-volume positions, and boundary positions (1 SD) were measured. In-house software created three-dimensional overlap distributions, including all observers. The effects of dental artifacts and observer experience on contouring precision were investigated, and the need for contrast media was assessed. RESULTS: In the absence of artifacts, all 9 participants achieved reasonable precision (1 SD < or =3 mm all boundaries). The structures obscured by dental image artifacts had larger variations when measured by the 3 metrics (1 SD = 8 mm cranial/caudal boundary). Experience improved the interobserver consistency of contouring for structures obscured by artifacts (1 SD = 2 mm cranial/caudal boundary). CONCLUSIONS: Interobserver contouring variability for anatomic H&N structures, specifically oropharyngeal gross tumor volumes and parotid glands, was acceptable in the absence of artifacts. Dental artifacts increased the contouring variability, but experienced participants achieved reasonable precision even with artifacts present. With a staging contrast CT image as a reference, delineation on a noncontrast treatment planning CT image can achieve acceptable precision.