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Biomedical subjects

K K Li

Publications and source records attributed to K K Li.

At least 55 records · Page 3Linked to original sources
PubMed1997

Optic nerve decompression for compressive neuropathy secondary to neoplasia.

OBJECTIVE: To evaluate the outcome of extracranial optic nerve decompression in patients with compressive optic neuropathy secondary to intracranial, paranasal sinus, or orbital neoplastic processes. DESIGN: A retrospective chart review and clinical follow-up of patients who underwent optic nerve decompression. SETTING: Tertiary care referral center. PATIENTS: During an 8-year period, 95 extracranial optic nerve decompressions were performed by one of us (M.P.J.) for optic neuropathy resulting from traumatic, inflammatory, infectious, iatrogenic, neoplastic, and idiopathic processes. Thirty patients with compressive optic neuropathy secondary to histopathologically confirmed tumors were identified. INTERVENTION: Optic nerve decompression via external ethmoidectomy approach. RESULTS: Twenty (67%) of 30 patients showed improvement in vision. Improvement in 17 of the 20 patients has been stable. Seven patients (23%) showed no improvement but there was no further worsening of vision after surgery. In 3 patients (10%) vision deteriorated following surgery. CONCLUSION: Extracranial optic nerve decompression may be considered for the preservation or improvement of vision in selected patients with compressive optic neuropathy from neoplasms.

Adult↗
PubMed1997

Obstructive sleep apnea surgery: risk management and complications.

BACKGROUND: Hypoxemia, hypertension, airway obstruction, and death have been associated with surgery for obstructive sleep apnea syndrome (OSAS). Patient analysis was undertaken to identify potential factors that could affect risk-management outcome. METHODS: One hundred eighty-two consecutively treated patients with OSAS undergoing 210 procedures were evaluated. Fifty-four factors were analyzed. RESULTS: Group characteristics included a mean age of 48.2 years, a mean respiratory disturbance index of 42.3, and a mean low oxyhemoglobin desaturation (LSAT) of 77.5%. Surgery included a combination of uvulopalatopharyngoplasty (162 patients; 77%) and maxillofacial procedures (173 patients; 82%). Patients with a respiratory disturbance index greater than 40 and an LSAT less than 80% (117 patients; 64%) were maintained on nasal continuous positive airway pressure. Thirty-nine patients (18.6% had difficult intubations. There was a positive correlation (p > 0.001) of difficult intubations, neck circumference (> 45.6 cm) and skeletal deficiency (Sella-Nasion-Point B < 75 degrees). All tubes were removed with the patient awake in the operating room with two transient episodes of airway obstruction. One hundred forty-eight of the patients (70.5%) required postoperative intravenous antihypertensive medications. Patients with a preoperative history of hypertension had a significantly increased risk (p > 0.01) of requiring intraoperative and postoperative intravenous antihypertensive medications. The mean hospital stay was 2.2 days (SD +/- 0.9). Analgesia was achieved with intravenous morphine sulfate or meperidine HCl (intensive care unit) and oral oxycodone (non-intensive care unit). There were no significant oxyhemoglobin desaturations, irrespective of severity of OSAS or obesity (mean LSAT day 1, 94.8% (SD +/- 2.4); mean LSAT day 2, 95.5% (SD +/- 1.6)). Complications included postoperative bleeding (n = 4), infection (n = 5), seroma (n = 3), arrhythmia (n = 4), angina (n = 1), and loss of skeletal fixation (n = 1). CONCLUSION: Intraoperative airway risks can be reduced by use of fiberoptic intubation in patients with increased neck circumference and skeletal deficiency. Patients with OSAS are at a significantly increased risk for hypertension. Nasal continuous positive airway pressure eliminated the postoperative risk of hypoxemia, which allowed the use of adequate parenteral or oral analgesics.

Female↗
PubMed1997

Experimental study of the safety of simultaneous nasal and Le Fort I osteotomies.

PURPOSE: This study evaluated the risk of unfavorable fractures extending to adjacent structures from nasal osteotomies during simultaneous rhinoplasty and Le Fort I osteotomy. MATERIALS AND METHODS: Sixteen nasal osteotomies (medial and lateral) were performed in conjunction with Le Fort I osteotomy on eight fresh cadaver heads. Skin and soft tissue of the face were removed and the patterns of fracture along the nasal bones and the presence of unfavorable fractures extending from the nasal osteotomies toward the orbit, skull base, and the maxillary osteotomy site were assessed. RESULTS: All 16 nasal osteotomies were successfully performed with a single pass of the osteotome. The nasal bones were easily mobilized in every instance. There were 11 (69%) complete fractures and five (31%) greenstick fractures at the superior aspect of the nasal bones. There were no unfavorable fractures extending from the nasal fracture sites toward the skull base, orbit, or the maxillary osteotomy site. CONCLUSION: Simultaneous Le Fort I osteotomy and nasal osteotomies can be performed without significant risk of unfavorable fractures or extension of the fracture lines to adjacent structures.

Contraindications↗
PubMed1997

Repair of traumatic orbital wall defects with nasal septal cartilage: report of five cases.

PURPOSE: This article reports the use of nasal septal cartilage for the repair of traumatic orbital wall defects. PATIENTS AND METHODS: Five patients with disruption of the orbital wall after facial trauma were included in this retrospective review. All of the patients underwent open reduction with internal fixation of the fractures as well as repair of the orbital wall defect with autogenous septal cartilage. RESULTS: Nasal septal cartilage was used in four cases of orbital floor defect and one case of orbital roof defect. All of the cases were successfully treated by restoration of the orbital wall continuity. CONCLUSION: Nasal septal cartilage is a readily accessible autogenous material that can be easily harvested with minimal donor site morbidity, and it should be considered when an autogenous orbital implant is needed for the repair of a traumatic orbital wall defect.

Adolescent↗
PubMed1997

Traumatic optic neuropathy complicating facial fracture repair.

Blindness can result from traumatic optic neuropathy following facial trauma and can complicate the management of concomitant facial fractures. Traumatic optic neuropathy can cause a substantial delay in the repair of facial fractures, leading to compromised surgical results. It can also result in postoperative visual loss following facial fracture repair. We present four cases of traumatic optic neuropathy that compromised the treatment of facial fractures. The management of facial fractures in patients with traumatic optic neuropathy must proceed cautiously. Delayed primary repair of midface fractures by postponing surgery for 10 to 14 days may be of benefit in avoiding further deterioration of vision. In addition, megadose corticosteroids and/or optic nerve decompression is useful in the management of these patients.

Adrenal Cortex Hormones↗
PubMed1997

Anatomic location of the tongue base neurovascular bundle.

Knowledge of the location of the hypoglossal/lingual artery neurovascular bundle (HLNVB) is essential in performing tongue base resections for neoplasm and for obstructive sleep apnea. Transoral and transcervical resections of the tongue base may be performed with greater exposure and certainty when the relationship of the HLNVB to local landmarks is understood; knowledge of the HLNVB allows resection of a larger amount of contralateral tongue base during partial glossectomy without violating the contralateral remnant tongue's blood supply. Ten cadaver heads were dissected to determine the position of the HLNVB with respect to soft tissue and bony landmarks at the tongue base. Our results indicate the position of the tongue base HLNVB is significantly inferior and lateral, that is, 2.7 cm inferior and 1.6 cm lateral to the foramen cecum, 0.9 cm superior to the hyoid bone, and 2.2 cm medial to the mandible. This inferolateral location allows the potential for aggressive tongue base resection without neurovascular compromise.

Humans↗
PubMed1996

Odontogenic keratocysts in the pediatric population.

OBJECTIVE: To review the characteristics and treatment of odontogenic keratocysts in the pediatric population at our institution in light of a comprehensive literature review of odontogenic keratocysts in the general population in the hope of elucidating clinical, radiological, or pathological factors that would suggest a different therapeutic approach to odontogenic keratocysts in the pediatric as opposed to the adult population. DESIGN: A 19-year retrospective medical chart review of children with mandibular or maxillary masses of odontogenic keratocyst origin. SETTING: Two academic tertiary care institutions. PATIENTS: Eleven children had pathologically confirmed odontogenic keratocysts. Age at diagnosis ranged from 8 to 18 years (mean, 13.4 years). RESULTS: A cystic mass with dentition displacement was characteristic clinically and radiographically. Treatment principally consisted of enucleation with or without extraction of teeth. Follow-up ranged from 1 to 8 years. Seven patients remained free of disease. Recurrences or second primary lesions occurred in 4 patients, all of whom had a family history of nevoid basal cell carcinoma syndrome or multiple cysts suggestive of this diagnosis. The maximum 8-year interval between initial treatment and recurrence is noteworthy. CONCLUSIONS: The diagnosis of odontogenic keratocyst deserves consideration in children who have a mass of the mandible or maxilla. The clinical behavior of this lesion in its initial occurrence and response to conservative treatment seems to be similar to that reported in adults. Odontogenic keratocysts, especially those that are multiple or recurrent, should alert the clinician to the possible underlying diagnosis of nevoid basal cell carcinoma syndrome.

Adolescent↗
PubMed1996

Fixed mandibular implant after microvascular mandibular reconstruction.

OBJECTIVE: To evaluate the use of fixed mandibular implants to retain dental prostheses after microvascular mandibular reconstruction. DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: Eight patients with microvascular mandibular reconstruction after mandibular resection. OUTCOME MEASURES: Clinically noted functional results, serial radiographic evidence of fixed mandibular implant and mandibular integrity, and complications encountered. RESULTS: Eight of 8 fixed mandibular implants were successfully placed and remained stable. The follow-up period ranged from 10 to 21 months (mean, 14.3 months). CONCLUSION: The use of fixed mandibular implants to retain dental prostheses after microvascular mandibular reconstruction is a safe and effective treatment option.

Aged↗
PubMed1996

Location of the descending palatine artery in relation to the Le Fort I osteotomy.

PURPOSE: This study evaluated the positional relationship of the descending palatine artery to the Le Fort I osteotomy. MATERIALS AND METHODS: Three separate examinations were performed. In the first, 30 human skulls were used, and measurements were made of the greater palatine canal and foramen in relation to maxillary landmarks pertaining to the Le Fort I osteotomy. In the second, 40 patients with normal or minimal sinus mucosal thickening were selected from a pool of patients who underwent computed tomography (CT) scanning for sinus evaluation. These patients were scanned on a Somatome Plus spiral CT scanner as part of a routine sinus protocol, with the addition of an axial image 3 mm above the nasal floor where the Le Fort I osteotomy is usually performed. The distance from the greater palatine canal to the piriform rim was measured. In the third, eight fresh cadavers were used, and the distance from the internal maxillary artery to the nasal floor was measured. RESULTS: The internal maxillary artery enters the pterygopalatine fossa approximately 16.6 mm above the nasal floor and gives off the descending palatine artery. The descending palatine artery travels a short distance within the pterygopalatine fossa and then enters the greater palatine canal. It travels approximately 10 mm within the canal in an inferior, anterior, and slightly medial direction to exit the greater palatine foramen in the region of the second and third molars. CONCLUSION: Injury to the descending palatine artery during Le Fort I osteotomy can be minimized by not extending the osteotomy more than 30 mm posterior to the piriform rim in females. This distance can be extended to 35 mm in males. Pterygomaxillary separation should be made by closely adapting the cutting edge of a curved osteotome or right-angled saw to the pterygomaxillary fissure while avoiding excessive anterior angulation. Furthermore, the superior cutting edge of the osteotome or saw blade should be less than 10 mm above the nasal floor.

Adolescent↗
PubMed1996

Reconstruction of the severely atrophic edentulous maxilla using Le Fort I osteotomy with simultaneous bone graft and implant placement.

PURPOSE: This study evaluated the outcome of patients who underwent simultaneous Le Fort I osteotomy, an interpositional bone graft, and implant placement for reconstruction of the severely atrophic edentulous maxilla. PATIENTS AND METHODS: Twenty patients operated by the same surgeon were included in the study. Patients were followed annually with clinical and radiographic examinations for an average of 33 months. RESULTS: One hundred thirty-nine implants were initially inserted in the bone grafts at the time of Le Fort I osteotomy. Twenty-five implants (18%) failed to osseointegrate. Seventeen of the 25 implants lost were from three patients. The most significant prognostic factor appeared to be the thickness of the atrophic maxillary ridge. Twelve of the 20 patients completed prosthetic restoration, with an average follow-up of 21 months after loading. No implants were lost after loading, and all prostheses have remained stable. CONCLUSIONS: This method of reconstruction of the severely atrophic maxilla achieves an implant survival rate of 82% while correcting the unfavorable maxillomandibular relationship commonly seen in these patients.

Adult↗
PubMed1996

Fractures of the atrophic, edentulous maxilla during Le Fort I osteotomy.

The incidence of unfavorable fractures of the maxilla during Le Fort I osteotomy was compared between patients with atrophic, edentulous maxillae and patients with normal dentate maxillae. Unfavorable fractures frequently occurred in atrophic, edentulous maxillae. The most common maxillary fracture involved the junction of the horizontal plate of the palatine bone and posterior part of the maxilla. Prevention strategies and treatment options are discussed.

Adolescent↗