Topical Hemostatic Agents and Risk of Postoperative Hemorrhage After Transoral Robotic Surgery.

Objective: Postoperative hemorrhage is the most common complication of transoral robotic surgery (TORS). The available research literature on topical hemostatic agents is deficient, despite their wide use. This study aims to evaluate the frequency and severity of hemorrhagic events after TORS procedures, performed with various topical hemostatic agents. Methods: This study was planned as a retrospective review to identify postoperative hemorrhage events in a database of all consecutive adult patients who required TORS from January 1, 2015, to April 1, 2020. All procedures were performed in one single institution by the same surgeon. In 2017, bovine gelatin matrix with thrombin (BgMT) was replaced by the porcine gelatin matrix with thrombin (PgMT) for all procedures. Postoperative hemorrhage was identified, along with hemostatic agents employed and other variables. Results: A cohort of 80 TORS procedures was obtained from a population of 78 individuals (60 males:18 females). BgMT was used in 28 procedures (35%), and five cases of postoperative hemorrhage were identified (17.8%), two of them were severe. PgMT was used in 52 procedures (65%) just observing one minor hemorrhagic event (1.92%). Although a significant difference was observed for total events between groups (P = .0183), there was no difference between major or severe hemorrhagic events (P = .1196). The overall rate of major and severe postoperative hemorrhage in the study population was 2.5% (n = 80). Conclusions: This is the first study to evaluate topical hemostatic agents during TORS procedures. The PgMT group had a reduced incidence of total postoperative hemorrhages, although there was no difference in the number of severe hemorrhagic events. The overall simplicity and cost-effectiveness of these agents would support their use, particularly considering the potential risk associated with airway hemorrhage.

Past, Present, and Future of Robotic Surgery.

Robotic-assisted surgery embodies the latest in technological advancement and is being applied to operative management of patients. The current concept of robotic surgery involves performance of surgical procedures by using small wristed instruments attached to a robotic arm. Its extension to otolaryngology is only natural, because it allows for precise surgery through anatomic orifices, often allowing for preservation of critical anatomic structures and functions. Transoral robotic surgery is an effective and safe tool for head and neck surgeons. Its speed of recent growth and the imminent addition of innovative technology could signal the advent of a new era in surgery.

Collagen Matrix With Mucoperiosteum Graft as an Effective Fatless Flapless Reconstruction After Endoscopic Pituitary Adenoma Resection.

BACKGROUND: Proper skull base reconstruction after endoscopic endonasal pituitary surgery is of great importance to decrease the rate of complications. OBJECTIVE: To assess the safety and efficacy of reconstruction with materials other than fat graft and naso-septal flaps (NSF) to avoid their associated morbidities. METHODS: The authors' institutional database for patients who underwent endoscopic endonasal approach for pituitary adenoma was reviewed. Exclusion criteria included recurrence, postradiation therapy, and reconstruction by fat graft or NSF. They were divided into group A, where collagen matrix (CM) (DuraGen® Plus Matrix, Integra LifeSciences Corporation, Plainsboro, New Jersey) alone was used; group B, where CM and simple mucoperiosteum graft were used and group C, which included cases without CM utilization. RESULTS: The study included 252 patients. No age, gender, or body mass index statistically significant difference between groups. Group B included the largest tumor size (23.0 mm) in comparison to groups A (18.0 mm) and C (13.0 mm). Suprasellar extension was more frequently present (49.4%) in comparison to groups A (29.8%, P = .001) and C (21.2%, P < .001). Postoperative cerebrospinal fluid (CSF) leak rate was 0%, 2.9%, and 6% in groups A, B, and C, respectively. In group B, the CSF leak rate decreased from 45.9% intraoperatively to 2.9% postoperatively (P < .001). In group A, the CSF leak reduction rate was almost statistically significant (P = .06). CONCLUSION: Utilization of CM and simple mucosperiosteal graft in skull base reconstruction following pituitary adenoma surgery is an effective method to avoid the morbidities associated with NSF or fat graft.

Salvage Free Tissue Transfer for Clival Osteoradionecrosis After Repeat Proton Beam Therapy.

BACKGROUND: Craniocervical junction chordoma treated with surgery and Proton Beam Therapy evolved with Osteonecrosis and CSF leak. As the vascularization of the head was compromised, we harvested an Anterolateral thigh musculofascial flap to seal the leak. CASE DESCRIPTION: A 56-year-old man presented with a history of chronic headaches and dysarthria with tongue deviation to the right. Magnetic resonance imaging showed a lesion at the craniocervical junction with imaging characteristics compatible with chordoma. Endoscopic endonasal resection was followed by proton beam therapy. Recurrence of the chordoma was subsequently resected via far lateral approach again followed by proton beam therapy accumulating a total dose of 75 Gy. Unfortunately, this led to osteoradionecrosis of the skull base resulting in a cerebrospinal fluid (CSF) leak more than 1 year after treatment. After multiple failed attempts to seal the defect using local vascularized tissue and free fat grafts, the defect was reconstructed with a vastus lateralis free tissue transfer. Six weeks later, the flap had mucosalized, the patient was pain free, and there was no evidence of a CSF leak. CONCLUSIONS: In select cases, vascularized free flaps offer a superior reconstruction for osteoradionecrosis because radiotherapy often compromises the blood supply of local tissues.

Peak Sinus Pressures During Sneezing in Healthy Controls and Post-Skull Base Surgery Patients.

OBJECTIVES/HYPOTHESIS: Patients are frequently advised to sneeze with an open mouth and avoid nose-blowing following an endoscopic endonasal approache (EEA) to the skull base, despite a lack of quantitative evidence. This study applies computational fluid dynamics (CFD) to quantify sinus pressures along the skull base during sneezing. STUDY DESIGN: Case-control series. METHODS: Computed tomography or magnetic resonance imaging scans of four post-EEA patients and four healthy controls were collected and analyzed utilizing CFD techniques. A pressure drop of 6,000 Pa was applied to the nasopharynx based on values in the literature to simulate expiratory nasal airflow during sneezing. Peak pressures along the skull base in frontal, ethmoid, and sphenoid sinuses were collected. RESULTS: Significant increases in skull base peak pressure was observed during sneezing, with significant individual variations from 2,185 to 5,685 Pa. Interestingly, healthy controls had significantly higher pressures compared to post-EEA patients (5179.37 ± 198.42 Pa vs. patients 3,347.82 ± 1,472.20 Pa, P < .05), which could be related to higher anterior nasal resistance in unoperated healthy controls (0.44 ± 0.22 vs. 0.31 ± 0.16 Pa/mL/sec for patients, P = .38). The sinus pressure buildup may be due to airway resistance functioning as a valve preventing air from being released quickly. Supporting this theory, there was a strong correlation (r = 0.82) between peak skull base pressure and the ratio of anterior resistance to total resistance. Within-subject variation in pressures between different skull base regions was much lower (average = ~5%). CONCLUSIONS: This study provided the first quantitative analysis of air pressure along the skull base during sneezing in post-EEA patients through CFD, suggesting that pressure buildup may depend on individual anatomy. LEVEL OF EVIDENCE: 3b Laryngoscope, 130:2138-2143, 2020.

Does 3D volumetric analysis predict the reach of endoscopically harvested buccal fat pad flap.

OBJECTIVES: To determine if the volume of buccal fat, ascertained by computed tomography (CT) scanning, would correspond to surface area and reach (length and width) of the flap intraoperatively to aid in the reconstruction of selected skull base defects. METHODS: Cadaveric study of five specimens, 10 sides. Methods CT imaging and evaluation using the Osirix 9 software (Pixmeo; Bernex, Switzerland). of cadaveric heads to calculate the volume of the buccal fat bilaterally. The flap was then harvested endoscopically. Measurements were taken. Two heads were also dissected via a transfacial approach. RESULTS: The volume of the buccal fat pad (BFP) as well as the maximum length and width of the endoscopically harvested flap were documented. There was a positive correlation shown between the calculated volume of the BFP based on CT imaging and the dissected length and width of the flap (Pearson correlation, r = 0.83 and r = 0.80, respectively). The transfacial dissection demonstrated the lobes of the BFP well, showing that most of the endoscopic mobilization of the BFP was limited to the posterior lobe, in particular to the temporalis and pterygoid components, with minimal displacement of the superficial components. This minimized the risk of visibly hollowing the buccal fullness. CONCLUSION: Preoperative calculation of the CT-based volume of the BFP correlates positively with the intraoperative maximum reach of the flap for both length and width. Whereas the volume may be lower in some instances, the BFP would still have adequate reach to provide coverage for the lower and mid-clival region in most patients. LEVEL OF EVIDENCE: NA. Laryngoscope, 130:1670-1673, 2020.

The Role of Endonasal Endoscopic Optic Nerve Decompression as the Initial Management of Primary Optic Nerve Sheath Meningiomas.

Background The management of optic nerve sheath meningiomas (ONSMs) remains controversial. Surgical decompression through traditional resective techniques has been associated with significant morbidity. While radiation therapy, the current modality of choice is not exempt of risks. Transnasal endoscopic optic nerve decompression (EOND) offers a direct route to the orbit, optic canal, and orbital apex, providing a minimally invasive alternative. Objective The main objective of this article is to assess EOND as the initial management of symptomatic patients with primary ONSM. Methods Patients with ONSMs without a history of radiotherapy who underwent EOND were retrospectively reviewed. Postoperative imaging, duration of follow-up, and visual outcomes at the last ophthalmology visit were assessed. Results Four women (age range 25-63 years) with primary ONSMs that underwent EOND were identified. All patients displayed subjective and objective baseline signs of vision loss. Additionally, baseline proptosis, diplopia, optic nerve atrophy, and ocular pain were identified. In none of the cases, the optic nerve sheath was breached. Following EOND, all patients deferred treatment with adjuvant radiotherapy. At a mean postoperative follow-up of 14 months, all patients were clinically stable without evidence of disease progression on imaging or physical examination. At last ophthalmologic evaluation, three out of four showed objective improvements from baseline visual acuity and visual field (remaining patient had baseline optic nerve atrophy). Conclusion These results suggest that EOND could be a viable initial treatment modality of selected primary ONSM cases. Further studies are warranted to determine long-term efficacy and its role in a stepwise progression of management, preceding radiotherapy.

Computational fluid dynamic analysis of aggressive turbinate reductions: is it a culprit of empty nose syndrome?

BACKGROUND: Empty nose syndrome (ENS) remains highly controversial, with aggressive inferior turbinate reduction (ITR) or mucociliary dysfunction frequently implicated. However, the appropriate degree of ITR is highly debatable. METHODS: We applied individual computed tomography (CT)-based computational fluid dynamics (CFD) to 5 patients receiving relatively aggressive ITR but with no ENS symptoms, and compared them to 27 symptomatic ENS patients who all had histories of aggressive ITRs, and 42 healthy controls. Patients' surgical outcomes were confirmed with 22-item Sino-Nasal Outcome Test (SNOT-22) (ITR: 6.40 ± 4.56; ENS: 58.2 ± 15.9; healthy: 13.2 ± 14.9), Nasal Obstruction Symptom Evaluation (NOSE) scores (ITR: 4.00 ± 2.24; ENS: 69.4 ± 17.1; healthy: 11.9 ± 12.9), and Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) (≥11 for ENS). RESULTS: Both aggressive ITR without ENS symptoms and symptomatic ENS patients had significantly lower nasal resistance (ITR: 0.059 ± 0.020 Pa·s/mL; ENS: 0.052 ± 0.015 Pa·s/mL; healthy: 0.070 ± 0.021 Pa·s/mL) and higher cross-sectional areas surrounding the inferior turbinate (ITR: 0.94 ± 0.21 cm2 ; ENS: 1.19 ± 1.05 cm2 ; healthy: 0.42 ± 0.22 cm2 ) than healthy controls. The lack of significant differences among patient groups indicated similar degrees of surgeries between ITR with and without ENS symptom cohorts. However, symptomatic ENS patients have paradoxical significantly less airflow in the inferior meatus (ITR: 47.7% ± 23.6%; ENS: 25.8% ± 17.6%; healthy: 36.5 ± 15.9%; both p < 0.01), but higher airflow around the middle meatus (ITR: 49.7% ± 22.6%; ENS: 66.5% ± 18.3%; healthy: 49.9% ± 15.1%, p < 0.0001) than aggressive ITR without symptoms and controls. Aggressive ITR patients have increased inferior meatus airflow as expected (p < 0.05). This imbalanced airflow produced less inferior wall-shear-stress distribution among symptomatic ENS patients only (ITR: 42.45% ± 11.4%; ENS: 32.2% ± 12.6%; healthy: 49.7% ± 9.9%). ENS patients (n = 12) also had impaired nasal trigeminal function, as measured by menthol lateralization detection thresholds (ITR: 15.2 ± 1.2; ENS: 10.3 ± 3.9; healthy: 13.8 ± 3.09, both p < 0.0001). Surprisingly, aggressive ITR patients without ENS symptoms have better menthol lateralization detection thresholds (LDTs) than healthy controls. CONCLUSION: Although turbinate tissue loss is linked with ENS, the degree of ITR that might distinguish postoperative patient satisfaction in their nasal breathing vs development of ENS symptoms is unclear. Our results suggest that a combination of distorted nasal aerodynamics and loss of mucosal sensory function may potentially lead to ENS symptomology.

Asymptomatic vs symptomatic septal perforations: a computational fluid dynamics examination.

BACKGROUND: A nasal septal perforation (NSP) can lead to frustrating symptoms for some patients while remaining completely asymptomatic for others, without a clear mechanism differentiating them. METHODS: We applied individual computed tomography (CT)-based computational fluid dynamics (CFD) to examine the nasal aerodynamics differences between 5 asymptomatic and 15 symptomatic NSP patients. Patients' symptoms were confirmed through interviews, 22-item Sino-Nasal Outcome Test score (asymptomatic, 25 ± 18.8; symptomatic, 53.7 ± 18.2), nasal obstruction symptom evaluation score (asymptomatic, 28.0 ± 32.1; symptomatic, 62.2 ± 32.2), and review of medical history. RESULTS: No statistical differences were found in perforation location, size (asymptomatic, 1.94 ± 1.88 cm2 ; symptomatic, 1.36 ± 1.44 cm2 ), nasal resistance (asymptomatic, 0.059 ± 0.012 Pa·s/mL; symptomatic, 0.063 ± 0.022 Pa·s/mL), and computed flow rate shunting across the perforation (asymptomatic, 52.9 ± 30.9 mL/s; symptomatic, 27.4 ± 23.6 mL/s; p > 0.05). However, symptomatic patients had significantly higher wall shear stress (WSS) and heat flux, especially along the posterior perforation margin (WSS, 0.54 ± 0.12 vs 1.15 ± 0.49 Pa, p < 0.001; heat flux, 0.21 ± 0.05 vs 0.37 ± 0.14 W/cm2 , p < 0.01). A WSS cutoff at 0.72 Pa can separate asymptomatic vs symptomatic NSP with 87% sensitivity and 100% specificity. Flow visualization showed flow peaks toward the posterior margin that may be responsible for the high WSS and heat flux among symptomatic NSPs. CONCLUSION: This study is the first CFD examination of asymptomatic and symptomatic NSP with regional aerodynamics and stress abnormalities, beyond size or location, being implicated as the mechanism behind the symptomology of NSP. This finding could serve as an objective basis for future personalized treatment decisions and optimization.

Computational fluid dynamics after endoscopic endonasal skull base surgery-possible empty nose syndrome in the context of middle turbinate resection.

BACKGROUND: Empty nose syndrome (ENS) is a rare and debilitating disease with a controversial definition, etiology, and treatment. One puzzling fact is that patients who undergo an endoscopic endonasal approach (EEA) often have resection of multiple anatomic structures, yet seldom develop ENS. In this pilot study, we analyzed and compared the computational fluid dynamics (CFD) and symptoms among post-EEA patients, ENS patients, and healthy subjects. METHODS: Computed tomography scans of 4 post-EEA patients were collected and analyzed using CFD techniques. Two patients had significant ENS symptoms based on results of the Empty Nose Syndrome 6-item Questionnaire (score >11), whereas the other 2 were asymptomatic. As a reference, their results were compared with previously published CFD results of 27 non-EEA ENS patients and 42 healthy controls. RESULTS: Post-EEA patients with ENS symptoms had a similar nasal airflow pattern as non-EEA ENS patients. This pattern differed significantly from that of EEA patients without ENS symptoms and healthy controls. Overall, groups with ENS symptoms exhibited airflow dominant in the middle meatus region and a significantly lower percentage of airflow in the inferior turbinate region (EEA with ENS, 17.74 ± 4.00% vs EEA without ENS, 51.25 ± 3.33% [t test, p < 0.02]; non-EEA ENS, 25.8 ± 17.6%; healthy subjects, 36.5 ± 15.9%) as well as lower peak wall shear stress (EEA with ENS, 0.30 ± 0.13 Pa vs EEA without ENS, 0.61 ± 0.03 Pa [p = 0.003]; non-EEA ENS, 0.58 ± 0.24 Pa; healthy subjects, 1.18 ± 0.81 Pa). CONCLUSION: These results suggest that turbinectomy and/or posterior septectomy may have a varying functional impact and that ENS symptoms go beyond anatomy and correlate with aerodynamic changes. The findings open the door for CFD as a potential objective diagnosis tool for ENS.

Modified endoscopic endonasal approach with a minimally invasive transoral approach-an adjunct to infrapetrous approaches.

OBJECTIVES/HYPOTHESIS: To evaluate the potential of a minimally invasive transoral-transpalatal approach (MITA) to the retrocarotid petrous apex, as an adjunct to endoscopic endonasal approaches (EEAs). STUDY DESIGN: Cadaver study. METHODS: Five cadaveric specimens were dissected raising an inverted U-shaped palatal mucoperiosteal flap, and drilling a rectangular palatotomy (between the greater palatine foramens, and just anterior to the palatine aponeurosis). This allowed a transpterygoid EEA with cross-court access (contralateral line of sight), followed by an extradural clivectomy that exposed the petroclival junction bilaterally. Surgical targets were marked on the posterior and medial surface of the petrous internal carotid artery (ICA), at its anterior genu, midhorizontal portion, and posterior genu. For each target and approach, the surgical freedom and angles of approach (in the horizontal and vertical planes) were calculated and statistically compared. RESULTS: Compared to EEA, the MITA resulted in greater surgical freedom for all targets, with the highest values at the anterior genu (1,661.37 mm2 vs. 312.76 mm2 , P <.001), and maintaining superiority in this regard all the way to the posterior genu (847.84 mm3 vs. 138.91 mm3 , P < .005). MITA also offered greater angles of approach for all targets. CONCLUSIONS: This study suggests that the MITA may be indicated to supplement the exposure provided by a transpterygoid EEA. This technique, associated with low potential morbidity, offers an alternative to internal carotid lateralization while managing extradural lesions that are adjacent to the petrous ICA. LEVEL OF EVIDENCE: NA Laryngoscope, 129:339-343, 2019.

Surgical simulation of a catastrophic internal carotid artery injury: a laser-sintered model.

BACKGROUND: The catastrophic and rare nature of an internal carotid artery (ICA) injury during endonasal surgery limits training opportunities. Cadaveric and animal simulation models have been proposed, but expense and complicated logistics have limited their adoption. Three-dimensional (3D) printed models are portable, modular, reusable, less costly, and proven to improve psychomotor skills required for managing different lesions. In this study we evaluate the role of a simplified laser-sintered model combined with standardized training in improving the effectiveness of managing an ICA injury endoscopically. METHODS: A 3-mm defect was created in the parasellar carotid canal of a laser-sintered model representing a sphenoid sinus. Artificial blood was directed to simulate the copious bleeding arising from an ICA injury. Twenty otolaryngologists and 26 neurosurgeons, with varying training and experience levels, were individually asked to stop the "bleeding" as they would in a clinical scenario, and provided no other instructions. This was followed by individualized formative training and a second simulation. Volume of blood loss, time to hemostasis, and self-assessed confidence scores were compared. RESULTS: At the end of the study, time to hemostasis was reduced from 105.49 seconds to 40.41 seconds (p < 0.001). The volume of blood loss was reduced from 690 to 272 mL (p < 0.001), and the confidence scores increased in 95.7% of participants, from an average of 3 up to 8. CONCLUSION: This ICA injury model, along with a formal training algorithm, appears to be valuable, realistic, portable, and cost-effective. Significant improvement in all parameters suggests the acquisition of psychomotor skills required to control an ICA injury.

Investigation of the abnormal nasal aerodynamics and trigeminal functions among empty nose syndrome patients.

BACKGROUND: Abnormal nasal aerodynamics or trigeminal functions have been frequently implicated in the symptomology of empty nose syndrome (ENS), yet with limited evidence. METHODS: Individual computed tomography (CT)-based computational fluid dynamics (CFD) was applied to 27 ENS patients to simulate their nasal aerodynamics and compared with 42 healthy controls. Patients' symptoms were confirmed with Empty Nose Syndrome 6-item Questionnaire (ENS6Q), 22-item Sino-Nasal Outcome Test (SNOT-22), and Nasal Obstruction Symptom Evaluation (NOSE) scores. Nasal trigeminal sensitivity was measured with menthol lateralization detection thresholds (LDTs). RESULTS: ENS patients had significantly lower (∼25.7%) nasal resistance and higher (∼2.8 times) cross-sectional areas compared to healthy controls (both p < 0.001). Despite inferior turbinate reductions, CFD analysis demonstrated that ENS patients had increased airflow concentrated in the middle meatus region (66.5% ± 18.3%) compared to healthy controls (49.9% ± 15.1%, p < 0.0001). Significantly less airflow (25.8% ± 17.6%) and lower peak wall shear stress (WSS) (0.58 ± 0.24 Pa) were found in the inferior meatus (vs healthy: 36.5% ± 15.9%; 1.18 ± 0.81 Pa, both p < 0.05), with the latter significantly correlated with the symptom scores of ENS6Q (r = -0.398, p = 0.003). Item-wise, complaints of "suffocation" and "nose feels too open" were also found to be significantly correlated with peak WSS around the inferior turbinate (r = -0.295, p = 0.031; and r = -0.388, p = 0.004, respectively). These correlations were all negative, indicating that less air-mucosal stimulations resulted in worse symptom scores. ENS patients (n = 12) also had impaired menthol LDT when compared to healthy controls (p < 0.0001). CONCLUSION: This is the first CFD examination of nasal aerodynamics in a large cohort of ENS patients. The results indicated that a combination of loss of neural sensitivity and poorer inferior air-mucosal stimulation may potentially lead to ENS symptomology.