Adhesives in otology and neurotology

A new device for real-time peroperative monitoring of ossicular chain reconstruction during middle ear surgery

To limit functional surgical failure and reduce the rate of revision surgery in case of surgical ossicular chain reconstruction, a piezoelectric device was developed for assessment of ossicular chain vibrations during the middle ear surgery. The device resembled a pen and consisted of a reusable main body and a disposable sensitive head including piezoelectric polymer sensor. Almost all of components of the device were made of polymer for light weight and for acoustic impedance matching to the middle ear system. Several frequencies can be analyzed simultaneously and several measures can be taken by time. The results showed that the device can record normal and reconstructed ossicular chain vibration in response to an acoustic stimulation, with similar results to those achieved by laser Doppler vibrometer. This light, handheld and low-cost device allows fast, easy and safe assessments of normal ossicular chain mobility and ossicular chain reconstruction efficiency. Primary pre-clinical trial showed very promising performance of the device that could be used to qualitatively control ossiculoplasty during real-time surgical procedure. Clinical assessments will be done to further evaluate the real-life performance of the device.

Preliminary application of intra-operative hearing monitoring by tone pip ABR via loudspeakers

CONCLUSION

This method might be an effective intra-operative way to access hearing threshold under general anesthesia in the operating room.

OBJECTIVE

To develop an intra-operative hearing monitoring method for surgeons to access hearing threshold under general anesthesia in the operating room.

METHOD

System establishment and calibration was done firstly. Normal hearing (NH) and conductive hearing loss (CHL) participants were recruited. This study applied pure tone audiometry (PTA) to all subjects and tone pip ABR (tp-ABR) via loudspeakers in sound booth and operating room for NH and CHL subjects, respectively. For NH subjects, Bland Altman was conducted to compare 1k Hz PTA and tp-ABR threshold. For CHL participants, Paired t-test, Satterth waite t'-test, and linear correlation analysis were used to compare the two methods. p < .05 was considered statistically different.

RESULTS

(1) Bland Altman showed all plots were inside the 95% confidence interval, indicating that there was no difference between the two methods for NH subjects. (2) The two methods had a high correlation (Pearson's coefficient =0.872 > 0.6, p < .05) in assessing hearing threshold in the operating room. (3) Satterth waite t'-test showed the ossicular chain malfunction enlarged the deviation of threshold by the two methods (.01 < p < .025).

Transfacial Recess Ossicular Reconstruction: Technique and Early Results

OBJECTIVES

The objective of this study was to present the technique of transfacial recess ossicular chain reconstruction (TFROCR) for potential use in selected patients with cholesteatoma.

STUDY DESIGN

The author conducted a retrospective case review of all candidates for TFROCR between August 1998 and March 2003.

SETTING

A tertiary referral center.

PATIENTS

At first-stage tympanomastoidectomy, 22 ears (21 patients; 8 children and 13 adults) with cholesteatoma and ossicular discontinuity were identified as candidates for TFROCR. Seven patients had undergone previous tympanomastoid surgery.

INTERVENTION

The first stage included canal wall up mastoidectomy with resection of disease, wide opening of the facial recess, cartilage graft tympanoplasty, and placement of silicone elastomer in the middle ear. Approximately 6 months later, patients underwent a second-stage postauricular procedure. Endoscopes were used to inspect the middle ear through the facial recess. When possible, TFROCR was then performed without elevating a tympanomeatal flap.

MAIN OUTCOME MEASURES

Variations in anatomy, disease control, and hearing results were studied.

RESULTS

Of the 22 candidate ears, 17 successfully underwent TFROCR, whereas 5 required traditional second-stage procedures with canal incisions. There were no surgical complications. Early hearing results are promising with an average air-bone gap of less than 20 dB. There have been no early failures from recurrent disease or prosthesis displacement.

CONCLUSIONS

In carefully selected patients, TFROCR could be safe and effective for disease control and hearing restoration. It could provide for optimal prosthesis placement and almost immediate hearing improvement, avoiding the need for canal incisions, middle ear packing, and dry ear precautions. One must consider the potential risk of missing residual disease secondary to limited exposure.

Fibrin sealant improves hemostasis in peripheral vascular surgery: a randomized prospective trial

OBJECTIVE

To evaluate the efficacy and safety of an investigational fibrin sealant (FS) in a randomized prospective, partially blinded, controlled, multicenter trial.

SUMMARY BACKGROUND DATA

Upper extremity vascular access surgery using polytetrafluorethylene (PTFE) graft placement for dialysis was chosen as a reproducible, clinically relevant model for evaluating the usefulness of FS. The FS consisted of pooled human fibrinogen (60 mg/mL) and thrombin (500 NIH U/mL). Time to hemostasis was measured, and adverse events were monitored.

METHODS

Consenting adult patients (n = 48) undergoing placement of a standard PTFE graft were randomized in a 2:1:1 ratio to the treatment group using FS (ZLB Bioplasma AG, Bern, Switzerland), oxidized regenerated cellulose (Surgicel, Johnson & Johnson, New Brunswick, NJ), or pressure. Patients received heparin (3,000 IU IVP) before placement of vascular clamps. If the treatment was FS, clamps were left in place for 120 seconds after the application of study material to permit polymerization. If treatment was Surgicel, clamps were left in place until the agent had been applied according to manufacturer's instructions. If the treatment was pressure, clamps were released as soon as the investigator was ready to apply compression. Immediately after release of the last clamp, the arterial and venous suture lines were evaluated for bleeding. The time to hemostasis at both the venous and arterial sites was recorded.

RESULTS

Significant (P < or =.005) reduction in time to hemostasis was achieved in the FS group. Thirteen (54.2%) patients randomized to FS experienced immediate hemostasis at both suture lines following clamp removal compared to no patients using Surgicel or pressure. Only one patient (7.1%) in the Surgicel group and no patients in the pressure group experienced hemostasis at 120 seconds from clamp removal, compared to 13 (54.2%) patients for FS. Adverse events were comparable in all groups. There were no seroconversions.

CONCLUSIONS

FS achieved more rapid hemostasis than traditional techniques in this peripheral vascular procedure. FS use appeared to be safe for this procedure.

Fibrin Sealant Facilitates Hemostasis in Arteriovenous Polytetrafluoroethylene Grafts for Renal Dialysis Access

A prospective randomized study was performed to evaluate the efficacy of fibrin sealant (FS) in patients undergoing upper-extremity polytetrafluoroethylene (PTFE) graft placement for dialysis. This procedure appears to be a reproducible and clinically relevant model for evaluating FS in vascular surgery. Consenting adult patients (n = 28) undergoing placement of a PTFE graft (6 mm) were randomized to either the treatment group using FS (Hemaseel APR, Haemacure Corp., Sarasota, FL) or control comparator groups (four) of bovine thrombin (T) (Thrombogen, GenTrac Inc., Middleton, WI), pressure (P), bovine thrombin (Thrombogen, GenTrac Inc.) -soaked cellulose sponges (TG) (Gelfoam, Upjohn Co., Kalamazoo, MI), or oxidized regenerated cellulose (S) (Surgicel, Johnson & Johnson, New Brunswick, NJ). All patients received heparin (3000 IU intravenous push) before placement of vascular clamps. The mean time to hemostasis was 29.3 seconds for FS, 147.4 seconds for T, 872.2 seconds for P, 346 seconds for TG, and 1044.5 seconds for S. There were no significant adverse events. FS appeared to be a superior hemostatic agent in these vascular procedures. No complications from FS were noted.

Effect of Tympanic Perforations on the Detection of Distortion-product Otoacoustic Emissions

The detection of distortion-product otoacoustic emissions (DPOAEs) depends on the viability of the ear's conduction apparatus. However, tympanic membrane perforations and other conductive disorders have not been fully investigated with regard to the examination of DPOAEs. Using the guinea pig model, we made perforations of different sizes and loci on the tympanic membrane and collected DPOAE data for frequencies between 2,193 and 5,508 Hz for each condition. We found that small perforations, up to 25% of the area of the tympanic membrane, still allow us to detect emissions at the specified frequencies. However, perforations of 50% and larger, as well as those accompanied by traumatic perilymph fistulas and ossicular disarticulations, severely interfered with the detection of DPOAEs. We discuss the clinical relevance of these findings with respect to the potential uses of DPOAEs.