Anterior subannular T-tube for prolonged middle ear ventilation during tympanoplasty: evaluation of efficacy and complications.

OBJECTIVE: We previously described the use of anterior subannular T-tubes (n = 20) for long-term middle ear ventilation. In the current study, we examine a larger patient population (n = 38) and a longer follow-up interval (average >2 years) to evaluate the efficacy and safety of anterior subannular tympanostomy. STUDY DESIGN: Retrospective nonrandomized case review. SETTING: Tertiary referral hospital. PATIENTS: Our series consisted of 38 consecutive patients with a diagnosis of eustachian tube dysfunction, adhesive otitis media, or chronic otitis media with a perforation who underwent a tympanoplasty. INTERVENTION: A subannular T-tube was placed anteriorly at the time of tympanoplasty to provide long-term middle ear ventilation. MAIN OUTCOME MEASURES: The main outcomes of this study are tube position, tube patency, and middle ear ventilation. In addition, hearing was evaluated both preoperatively and postoperatively and any complications were noted. RESULTS: There were 38 patients and 38 ears that received an anterior subannular T-tube at the time of tympanoplasty. The study group consisted of 24 female patients and 14 male patents with a median age of 36 years (range, 10-75 yr). All 38 patients had eustachian tube dysfunction, 22 had adhesive otitis media, 23 had chronic otitis media, 13 had a cholesteatoma, 11 had tympanic membrane perforations, and 3 patients had a cleft palate. All patients underwent tympanoplasty. Eighteen patients had a concomitant ossiculoplasty and 7 had a mastoidectomy. Follow-up ranged from 1 month to 48 months (average, 26 mo). Three tubes had extruded within 2 years, in 1 case resulting in a persistent perforation. Postoperative complications included 1 patient with a partially extruded prosthesis, 2 patients with tipped prosthesis and persistent tympanic membrane retraction, and 1 patient with a plugged tube. All other tubes were patent and showed no evidence of migration. Furthermore, there were no cases of anterior canal blunting or ingrowth of epithelium around the tube. CONCLUSION: Anterior subannular tympanostomy is a safe and effective method for long-term middle ear ventilation in patients with chronic eustachian tube dysfunction.

Dental implantation for restoration of posttraumatic deformities: avulsion injuries.

Soft and hard tissue defects of the cranio- and maxillofacial area, especially after an avulsion injury, are challenging to reconstruct. Sophisticated soft and hard tissue transfer techniques have allowed satisfactory reconstruction of the gross anatomic structure. However, these methods do not allow optimal restoration of fine anatomic detail or function. The advent of dental implants and modified dental implants for craniofacial applications has allowed maximization of cosmetic and functional restoration. Prosthodontists are capable of fabricating subunits of the cranio- and maxillofacial area with fine detail, reproducing the coloring, texture, and idiosyncrasies of a patient's native skin. Dental implant technology has allowed these prostheses to be bone anchored, yielding a reproducible and stable attachment. This method of attachment in turn allows flexibility in the design of the prosthesis, to maximize restoration, and imparts an increased sense of confidence to the patient. Illustrated are six examples demonstrating the versatility of dental implants in the reconstruction of avulsion injuries of the cranio- and maxillofacial complex.

Histoplasma capsulatum necrotizing myofascitis of the upper extremity.

Necrotizing myofascial fungal infections of the upper extremity is a rare event even in immunocompromised hosts. We report the course of a renal transplant patient who developed extensive necrotizing myofascial infection of an upper extremity secondary to Histoplasma capsulatum. Initial, functional, upper limb salvage was achieved after aggressive surgical debridement and high doses of amphotericin B. The patient ultimately succumbed to systemic fungal sepsis. The etiology and treatment of these infections are discussed.

Fast axonal transport of kinesin in the rat visual system: functionality of kinesin heavy chain isoforms.

The mechanochemical ATPase kinesin is thought to move membrane-bounded organelles along microtubules in fast axonal transport. However, fast transport includes several classes of organelles moving at rates that differ by an order of magnitude. Further, the fact that cytoplasmic forms of kinesin exist suggests that kinesins might move cytoplasmic structures such as the cytoskeleton. To define cellular roles for kinesin, the axonal transport of kinesin was characterized. Retinal proteins were pulse-labeled, and movement of radiolabeled kinesin through optic nerve and tract into the terminals was monitored by immunoprecipitation. Heavy and light chains of kinesin appeared in nerve and tract at times consistent with fast transport. Little or no kinesin moved with slow axonal transport indicating that effectively all axonal kinesin is associated with membranous organelles. Both kinesin heavy chain molecular weight variants of 130,000 and 124,000 M(r) (KHC-A and KHC-B) moved in fast anterograde transport, but KHC-A moved at 5-6 times the rate of KHC-B. KHC-A cotransported with the synaptic vesicle marker synaptophysin, while a portion of KHC-B cotransported with the mitochondrial marker hexokinase. These results suggest that KHC-A is enriched on small tubulovesicular structures like synaptic vesicles and that at least one form of KHC-B is predominantly on mitochondria. Biochemical specialization may target kinesins to appropriate organelles and facilitate differential regulation of transport.

Sympathetic blockade of isolated rat hindlimbs by intra-arterial guanethidine: the effect on blood flow and arterial-venous shunting.

In order to improve the understanding of the role of sympathetic nerve degeneration in reimplantation failure, the hindlimbs of eight rats (Group I) underwent near-complete amputation. The soft tissues of the hindlimb were transected at the proximal thigh with the femoral artery, vein and femur left intact. The femoral vessels were clamped and guanethidine was infused into a branch of the femoral artery of the right leg of each animal, while saline was injected into the left leg. The clamps were removed after 15 minutes. A baseline preoperative injection of radiolabeled microspheres was made, and subsequent injections at 6, 12, 18, and 24 hours postoperation. Twelve rats (Group II) were then used to assess the amount of arterial-venous shunting preoperatively (n = 6) and at 18 hours postoperation (n = 6), by venous sampling. Blood flow to both limbs increased postoperation, but there was significantly more flow in the guanethidine treated limb at 18 and 24 hours postoperation. The amount of shunting was approximately 50% in both limbs at 18 hours, as compared to 10% preoperation. These results highlight the potential benefit of guanethidine and other sympathetic blocking agents in reimplantation to increase blood flow, decrease tissue ischemia and increase anastomotic patency rates. They also suggest that sympathetic nerve degeneration did not affect the volume of arterial-venous shunting in this model, but the difference in blood flow was likely due to arteriolar vasospasm. Further study is needed to elucidate the clinical significance of sympathetic nerve degeneration in reimplantation failure.

Biomechanical comparison of wire osteosynthesis techniques in craniofacial surgery.

The biomechanical stability of 20 different craniofacial wire osteosynthesis methods were tested in a simulated bone model. Utilizing wire fixation across a curved osteotomy site of an acrylic bar fixed at one end, compressive loading at the suspended end was used to test the resistance of the ligatures to stretch failure. Twenty-eight- and 30-gauge ligature patterns tested included single loops, double loops, and figure-eights across both 1- and 2-cm distances. A two-way analysis of variance was then used to determine the various effects of wire diameter, configuration, and loop length. The extensional deformation of ligature fixation was shown to be reduced by increasing the number of wire loops, reducing intraloop distances, or employing a slightly larger gauge diameter. The complex wiring configuration of a figure-eight technique was of no advantage over simple wire loops. In comparative strengths, two double loops were stronger than one double loop, and two single loops were stronger than one single loop or figure-eight. Comparable reductions in fixation strength were seen in all groups; there were larger intrabony distances between the burr holes or with the smaller gauge wire. These biomechanical ligature testing results are useful in those craniofacial skeletal sites where the use of more rigid fixation is either contraindicated or not desired.

Lower facial recontouring in craniofacial asymmetry.

The secondary correction of facial asymmetry due to early posterior cranial deformation is presented. The combination of mandibular skeletal reduction of the gonial angle and inferior border, masseter muscle thinning, and auricular setback can be an effective camouflage technique when the facial skeleton and occlusion do not require repositioning.

The epigastric fat transfer: an alternative free flap model in the rat.

A free epigastric fat flap, a modification of the well-known cutaneous groin flap, is described in the rat. Vascular perfusion was successfully restored when transferred to the neck of the rat in 75% of the rats that underwent surgery, as assessed by multiple postoperative stripping tests and select microangiography. This flap offers the advantages of familiar anatomy, ease of postoperative care without risk of flap trauma, and a challenge to microsurgical technique development for successful flap transfer execution. Therefore, this free flap provides an additional animal model for use in microsurgical training as well as a research tool in fat transplantation physiology.

Orbital teratoma associated with trigonocephaly.

A rare case of congenital orbital teratoma that developed concurrently with the clinical findings of metopic sutural synostosis in an infant is presented. A cause-and-effect and/or embryologic relationship between these two cephalic malformations is possible, although coincidental occurrence is equally probable. The proximity of these congenital anomalies permitted complete resolution in a one-stage craniofacial procedure without alteration in the surgical technique.