Application of the ORBEYE three-dimensional exoscope for microsurgical procedures.

BACKGROUND: Advances in digital imaging, screen technology, and optics have led to the development of extracorporeal telescopes, also known as exoscopes, as alternatives to surgical loupes (SLs) and traditional operating microscopes (OMs) for surgical magnification. Theoretical advantages of the exoscope over conventional devices include improved surgeon ergonomics; superior three-dimensional, high-definition optics; and greater ease-of-use. The ORBEYE exoscope, in particular, has demonstrated early efficacy in the surgical arena. The purpose of this study was to compare the ORBEYE with conventional microscopy. METHODS: In this case-control pilot study, we compared the ORBEYE (n = 22) with conventional microscopy (n = 27) across 49 consecutive microsurgical cases during a 6-week period. Both visualization methods consisted of breast, and head and neck cases, while the ORBEYE was also used for extremity and lymphedema microsurgical cases. The ORBEYE was utilized during flap dissection and microvascular anastomosis. Baseline demographics, operative time, ischemia time, and intra- and postoperative microvascular complications were examined and compared. Attending surgeons completed an ergonomics and performance survey postoperatively comparing the ORBEYE with their previous use of SL/OM using a 5-point Likert scale. RESULTS: There was no difference in operative time (507 ± 132 min vs. 522 ± 139, p = .714), ischemia time (77.9 ± 31.4 min vs. 77.5 ± 36.0, p = .972), or microsurgical complications (0% vs. 4%, p = 1) between the ORBEYE and conventional microscopy groups. In a survey administered immediately postoperatively, surgeons reported favorable ergonomics, excellent image quality, and ease of equipment manipulation using the exoscope. CONCLUSIONS: The ORBEYE is an effective microsurgical tool and may be considered as an alternative to conventional optical magnification technology.

Application of Three-Dimensional Printed Vascular Modeling as a Perioperative Guide to Perforator Mapping and Pedicle Dissection during Abdominal Flap Harvest for Breast Reconstruction.

BACKGROUND: Advancements in three-dimensional (3D) printing have enabled production of patient-specific guides to aid perforator mapping and pedicle dissection during abdominal flap harvest. We present our early experience using this tool to navigate deep inferior epigastric artery (DIEA) topography and evaluate its impact on operative efficiency and clinical outcomes. PATIENTS AND METHODS: Between January 2013 and December 2018, a total of 50 women underwent computed tomographic angiography (CTA)-guided perforator mapping prior to abdominal flap breast reconstruction, with (n = 9) and without (n = 41) 3D-printed vascular modeling (3DVM). Models were assessed for their accuracy in identifying perforator location and source-vessel anatomy, as determined by operative findings from 18 hemi-abdomens. The margin of error (MOE) for perforator localization using 3DVM was calculated and compared with CTA-derived measurements for the same patients. Flap harvest times, outcomes, and complications for patients who were preoperatively mapped using 3DVM versus CTA alone were analyzed. RESULTS: Overall, complete concordance was observed between 3DVM and operative findings with regards to perforator number, source-vessel origin, and DIEA branching pattern. By comparison, CTA interpretation of these parameters inaccurately identified branching pattern and perforator source-vessel origin in 28 and 33% of hemi-abdomens, respectively (p = 0.045 and p = 0.02). Compared with operative measurements, the average MOE for perforator localization using 3DVM was significantly lower than that obtained from CTA alone (0.81 vs. 8.71 mm, p < 0.0001). Reference of 3D-printed models, intraoperatively, was associated with a mean reduction in flap harvest time by 21 minutes (60.7 vs. 81.7 minutes, p < 0.001). Although not statistically significant, rates of perforator-level injury, microvascular insufficiency, and fat necrosis were lower among patients mapped using 3DVM. CONCLUSION: The results of this study support the accuracy of 3DVM for identifying DIEA topography and perforator location. Application of this technology may translate to enhanced operative efficiency and fewer perfusion-related complications for patients undergoing abdominal free flap breast reconstruction.

The Role of Sentinel Lymph Node Biopsy in the Management of Cutaneous Malignancies.

Sentinel lymph node biopsy uses the concept of selective lymphatic drainage and the lymphatic microvasculature to identify first-echelon nodes draining a given malignancy. Although initially considered difficult and unreliable in the head and neck, experience with the technique has improved and evolved significantly over the last 3 decades. It is now recognized to be accurate and reliable for regional nodal staging and detection of occult nodal metastasis in the head and neck. Although initially described for nodal staging of melanoma, the usefulness of sentinel lymph node biopsy continues to expand and is now extended to other cutaneous malignancies.

Electrocardiogram Screening in Children with Congenital Sensorineural Hearing Loss: Prevalence and Follow-up of Abnormalities.

Objective The purpose is to determine the prevalence of electrocardiogram (ECG) abnormalities, including borderline and prolonged QT, among screened children with sensorineural hearing loss (SNHL) and to analyze their subsequent medical workup. Study Design Institutional Review Board-approved case series with chart review. Setting Tertiary academic center. Subjects and Methods Cases from 1996 to 2014 involving pediatric patients (N = 1994) with SNHL were analyzed. Abnormal ECGs were categorized as borderline/prolonged QT or other. A board-certified pediatric cardiologist retrospectively determined the clinical significance of ECG changes. For follow-up analysis, children with heart disease, known syndromes, or inaccessible records were excluded. Results Among 772 children who had ECGs, 215 (27.8%) had abnormal results: 35 (4.5%) with QT abnormalities and 180 (23.3%) with other abnormalities. For children with QT abnormalities meeting inclusion criteria (n = 30), follow-up measures included cardiology referral (46.6%), repeat ECG by ear, nose, and throat (ENT) specialist (20%), clearance by ENT specialist with clinical correlation and/or comparison with old ECGs (20%), and pediatrician follow-up (6.7%). Documentation of further workup by ENT or referral was absent for 6.7%. For children with other ECG changes meeting inclusion criteria (n = 136), abnormalities were documented for 57 (41.9%); normal QT without other abnormality was documented for 18 (13.2%). The most common follow-up referrals were to pediatricians (16.9%) and cardiologists (10.3%). Among patients with clinically significant non-QT abnormalities mandating further evaluation (n = 122), 38 (31.1%) had documented follow-up in medical records. Conclusion There is a high prevalence of ECG abnormalities among children with congenital SNHL. If findings are confirmed by future studies, screening should be considered for congenital unilateral or bilateral SNHL, regardless of severity. We describe a standardized protocol for ECG screening/follow-up.

Decision making for the central compartment in differentiated thyroid cancer.

The central compartment is a common site for nodal spread from differentiated thyroid carcinoma, often occurring in patients without clinical or ultrasonographic (US) evidence of neck lymph node metastasis (cN0). However, the role of elective central compartment neck dissection (CND) among patients with DTC remains controversial. We performed a systematic literature review, also including review of international guidelines, with discussion of anatomic and technical aspects, as well as risks and benefits of performing elective CND. The recent literature does not uniformly support or refute elective CND in patients with DTC, and therefore an individualized approach is warranted which considers individual surgeon experience, including individual recurrence and complication rates. Patients (especially older males) with large tumors (>4 cm) and extrathyroidal extension are more likely to benefit from elective CND, but elective CND also increases risk for hypoparathyroidism and recurrent nerve injury, especially when operated by low-volume surgeons. Individual surgeons who perform elective CND must ensure the number of central compartment dissections needed to prevent one recurrence (number needed to treat) is not disproportionate to their individual number of central compartment dissections per related complication (number needed to harm).

Osteocutaneous radial forearm free flap in nonmandible head and neck reconstruction.

BACKGROUND: The osteocutaneous radial forearm free flap (RFFF) is a versatile flap primarily used to reconstruct composite defects involving the mandible. The purpose of this study was to describe our experience with this flap for nonmandible reconstruction. METHODS: All patients undergoing nonmandible osseous reconstruction with free-tissue transfer were reviewed. Patients with osteocutaneous RFFF reconstructions were evaluated. The retrospective review of all osteocutaneous RFFFs was performed from 1998 to 2014. RESULTS: One hundred forty-two nonmandible osseous reconstructions were performed. Twenty-five patients underwent nonmandible osteocutaneous RFFF reconstruction. Eleven patients failed previous nonmicrovascular reconstruction. Reconstruction was for defects of the: palatomaxillary complex (n = 15), orbitomaxillary complex (n = 4), nasomaxillary complex (n = 4), larynx (n = 1), and clavicle (n = 1). There were no flap compromises. Postoperative complications included: 2 partial intraoral dehiscences; 1 recipient-site infection; and 1 seroma. Eight reconstructions required secondary procedures to improve functional and/or cosmetic outcomes. CONCLUSION: The osteocutaneous RFFF is a robust flap that can be used to reconstruct composite defects involving bone and soft-tissue beyond the mandible.

Venous thromboembolism in head and neck cancer surgery.

BACKGROUND: Venous thromboembolism (VTE) is a major cause of perioperative morbidity and mortality. Historically, otolaryngology surgery has been seen as very low risk of VTE, given the relatively short procedures and healthy patient population. However, head and neck surgery patients have multiple additional risk factors for VTE compared to general otolaryngology patients, and only recently has research been directed at examining this population of patients regarding VTE risk. REVIEW: VTE has long been recognized as a major issue in other surgical specialties, with VTE rates of 15-60 % in some specialties in the absence of prophylaxis with either mechanical compression or anticoagulation. Multiple large-scale retrospective studies have shown that the incidence of VTE in otolaryngology patients is quite low, ranging between 0.1 and 1.6 %. However, these studies indicated that head and neck cancer patients may have an increased risk of VTE. Further retrospective studies focusing on head and neck cancer patients found a VTE rate of approximately 2 %, but one study also found a suspected VTE rate of 5.6 % based on clinical symptoms, indicating that retrospective studies may underreport the true incidence. A single prospective study found a 13 % risk of VTE after major head and neck surgery. Furthermore, risk stratification using the Caprini risk assessment model demonstrates that the highest risk patients may have a VTE risk of 18.3 %, although this may be lowered (but not eliminated) through the use of appropriate prophylactic anticoagulation. CONCLUSION: VTE is likely a more significant concern in head and neck surgery patients than previously realized. Appropriate prophylaxis with mechanical compression and anticoagulation is essential; risk stratification may serve as a useful tool to identify head and neck cancer patients at highest risk for VTE.

The role of postoperative hematoma on free flap compromise.

OBJECTIVES/HYPOTHESIS: Hematomas may develop in the postoperative setting after free tissue transfer. When hematomas occur, they can exert pressure on surrounding tissues. Their effect on the vascular pedicle of a free flap is unknown. We describe our incidence of hematoma in free flaps and outcomes when the flap is compromised. STUDY DESIGN: Retrospective chart review of 1,883 free flaps performed between July 1998 and June 2014 at a tertiary referral center. METHODS: Patients with free flap compromise due to hematoma were identified. Etiology, demographic data, and outcomes were evaluated. RESULTS: Eighty-eight (4.7%) patients developed hematomas. Twenty (22.7%) of those had flap compromise. Twelve compromises (60%) showed evidence of pedicle thrombosis. The salvage rate was 75% versus 54% in 79 flaps with compromise from other causes (P = .12). Mean time to detection of the hematoma was 35.3 hours in salvaged flaps compared to 91.6 hours in unsalvageable flaps (P = .057). Time to operating room (OR) from detection was 2.8 hours in salvageable flaps compared to 12.4 hours in nonsalvageable flaps (P = .053). The salvage rate for flaps that returned to the OR in <5 hours was 93.3% compared to 20% (P = .0049) for those that did not. Vascular thrombosis reduced salvage rate to 58.3% from 100% (P = .002) when there was no thrombosis. CONCLUSIONS: In our series hematomas developed rarely. When they did, 23% went on to develop flap compromise. Prompt recognition and re-exploration allowed for a high salvage rate. Vessel thrombosis predicted inability to salvage the flap. LEVEL OF EVIDENCE: 4

Pediatric airway reconstruction with a prefabricated auricular cartilage and radial forearm free flap.

Prefabricated composite free flaps for complex airway reconstruction have been described for an adult series at our institution. We extended this approach to a pediatric patient with lifelong subglottic stenosis who had failed previous open airway reconstructions. A staged procedure was utilized in which a composite graft was created using conchal cartilages and a radial forearm free flap. This reconstruction improved the patency of her airway and decreased her dependency on intermittent airway dilations. Airway reconstruction with prefabricated conchal cartilage composite free flaps may be used as a salvage procedure for complex pediatric airway reconstruction when other methods have failed.

Detection of intracochlear damage during cochlear implant electrode insertion using extracochlear measurements in the gerbil.

OBJECTIVES/HYPOTHESIS: An intraoperative monitoring algorithm during cochlear implant electrode insertion could be used to detect trauma and guide electrode placement relative to surviving hair cells. The aim of this report was to assess the feasibility of using extracochlear recording sites to monitor acoustically evoked responses from surviving hair cells and neural elements during implantation in an animal model. STUDY DESIGN: Animal experiments. METHODS: The normal-hearing gerbil was used. Two recording methods, one using a lock-in amplifier and another using Fourier analysis of recorded signals, were used to obtain frequency-specific information about the responses to tones. Amplitude and threshold determinations were made at the round window and at three extracochlear sites. To induce intracochlear damage, a platinum-iridium wire was inserted through the round window. The wire was advanced, and changes in the potentials were correlated with cochlear contact. Anatomic integrity was assessed using cochlea whole mount preparations. RESULTS: In general, the lock-in amplifier showed greater sensitivity and lower thresholds at higher frequencies relative to the Fourier method. Also, the lock-in amplifier was more resistant to masking effects. Both systems were able to detect loss of cochlear potentials secondary to intracochlear trauma. Histologic damage was seen in all cases and corresponded to electrophysiologic changes. CONCLUSIONS: Impact of electrodes on cochlear structures affecting cochlear performance could be detected from several extracochlear sites. The lock-in amplifier demonstrated greater sensitivity and resistance to noise when compared to the fast Fourier transform recording paradigm. The latter showed greater flexibility of detecting and separating hair cell and neural potentials.

Cochlear implantation in children with postlingual hearing loss.

OBJECTIVES/HYPOTHESIS: Although it is clear that early auditory stimulation through cochlear implantation (CI) has been shown to improve speech and language development trajectories for children with prelingual hearing loss, data supporting implantation in postlingual children are mostly lacking. The purpose of this study was to characterize speech perception abilities following CI in a group of children with previously well-developed language abilities. STUDY DESIGN: Retrospective analysis. METHODS: Twenty-eight hearing-impaired children who received CIs were selected for study based on the presence of well-developed spoken language skills before implantation. Fifteen children with prelingual hearing loss served as a control group. Speech perception skills were assessed using developmentally appropriate measures. RESULTS: Children with postlingual hearing loss showed a statistically significant improvement in open-set speech perception scores as early as 6 months following CI, whereas prelingual children demonstrated significant improvements only after 24 months of use. Despite these early disparities in performance, the two groups were similar 36 months after implantation and beyond (60 months of implant use). CONCLUSIONS: Children with well-developed language abilities before CI showed substantial (and statistically significant) early improvements in open-set speech perception abilities following implantation that continued beyond 2 years of follow-up. These results suggest that postlingual children are excellent candidates for CI.

Detection of intracochlear damage with cochlear implantation in a gerbil model of hearing loss.

HYPOTHESIS: Cochlear trauma due to electrode insertion can be detected in acoustic responses to low frequencies in an animal model with a hearing condition similar to patients using electroacoustic stimulation. BACKGROUND: Clinical evidence suggests that intracochlear damage during cochlear implantation negatively affects residual hearing. Recently, we demonstrated the usefulness of acoustically evoked potentials to detect cochlear trauma in normal-hearing gerbils. Here, gerbils with noise-induced hearing loss were used to investigate the effects of remote trauma on residual hearing. METHODS: Gerbils underwent high-pass (4-kHz cutoff) noise exposure to produce sloping hearing loss. After 1 month of recovery, each animal's hearing loss was determined from auditory brainstem responses and baseline intracochlear recording of the cochlear microphonic and compound action potential (CAP) obtained at the round window. Subsequently, electrode insertions were performed to produce basal trauma, whereas the acoustically generated potentials to a 1-kHz tone-burst were recorded after each step of electrode advancement. Hair cell counts were made to characterize the noise damage, and cochlear whole mounts were used to identify cochlear trauma due to the electrode. RESULTS: The noise exposure paradigm produced a pattern of hair cell, auditory brainstem response, and intracochlear potential losses that closely mimicked that of electrical and acoustic stimulation patients. Trauma in the basal turn, in the 15- to 30-kHz portion of the deafened region, remote from preserved hair cells, induced a decline in intracochlear acoustic responses to the hearing preserved frequency of 1 kHz. CONCLUSION: The results indicate that a recording algorithm based on physiological markers to low-frequency acoustic stimuli can identify cochlear trauma during implantation. Future work will focus on translating these results for use with current cochlear implant technology in humans.