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Biomedical subjects

J C Irish

Publications and source records attributed to J C Irish.

At least 37 records · Page 2Linked to original sources
PubMed1999

Supraomohyoid neck dissection. Is it diagnostic or therapeutic?

BACKGROUND: The supraomohyoid neck dissection (SOHND) is often performed in patients with cancer of the oral cavity, where there is no clinical or radiologic evidence of regional metastases. When on pathologic examination positive neck nodes are found, however, some consider it a curative operation, whereas others regard it as a staging procedure only. METHODS: We retrospectively reviewed 43 patients with cancer of the oral cavity who had a SOHND during the period from 1991 to 1994. All patients were staged as having N0 disease and had a total of 48 SOHNDs (38 unilateral, 5 bilateral). The follow-up period was at least 2 years. RESULTS: Seven of 48 N0-staged necks showed occult metastasis (15%). Two of these patients received postoperative radiotherapy. One of 7 (14%) patients with pathologic node-positive disease on the SOHND side developed recurrent ipsilateral neck disease during the follow-up period, whereas 4 (10%) recurrences developed in 41 necks that were pathologically staged as N0. Survival was 88% for patients with pathologically N0 necks versus 86% for patients with pathologically N+; disease. CONCLUSION: Supraomohyoid neck dissection is an effective staging procedure; however, in this group of patients, neck recurrence and patient survival after SOHND appear not to be related to pathology N stage. Also, SOHND with or without adjuvant radiotherapy appears to control the neck in the majority of patients, attesting to therapeutic efficacy. A prospective study is needed, however, to see if a "wait and see" policy does not achieve similar long-term outcome.

Head and Neck Neoplasms↗
PubMed1999

The free iliac crest and fibula flaps in vascularized oromandibular reconstruction: comparison and long-term evaluation.

BACKGROUND: A variety of free flaps have been successfully used for mandible reconstruction. This study compared the short- and long-term results of using the free iliac crest and fibula flaps. METHODS: We conducted a retrospective analysis of 117 patients who underwent mandibular reconstruction, 59 patients with iliac crest and 58 with free fibula. Accurate long-term functional assessment was possible in 31 cases in the iliac crest group and in 48 patients with fibular reconstruction. Anterior or combined anterolateral defects formed 72% and 64% in the iliac crest and fibula groups, respectively. The remainder were pure lateral defects. In both series, a skin paddle was included to provide either lining, skin cover, or both in 77% of the cases, whereas in 23% bone only was used. RESULTS: Complications included two perioperative deaths and three flap losses in the iliac crest group and five flap losses in the fibula group. Long-term functional and cosmetic assessment showed no statistically significant differences in oral continence (p > 0.9), speech (p = 0.57), and contour results (p = 0.80) between the two groups. However, oral deglutition was statistically significantly better in the fibula free flap group (p = 0.009). CONCLUSION: Although the fibula free flap is the flap of choice, the iliac crest is an excellent and reliable complementary flap for mandibular reconstruction.

Adult↗
PubMed1999

A matched control study of treatment outcome in young patients with squamous cell carcinoma of the head and neck.

OBJECTIVES/HYPOTHESIS: To determine if there is a difference in overall survival, cause-specific survival, and relapse-free rate between young patients (<40 years of age) with head and neck squamous cell carcinoma (HNSCC) and older patients (>40 years of age). STUDY DESIGN: A matched control study describing the outcome of 185 previously untreated HNSCC patients less than 40 years of age treated at the Princess Margaret Hospital, Toronto, Ontario, Canada, between 1958 and 1992. The young patient group was compared with a control group of older patients (> 40 years of age) which was selected randomly from an entire cohort of patients (n = 10,072) and matched for site, sex, and date of presentation. METHODS: The medical records were reviewed and data abstracted for demographic information, tobacco and alcohol use, family history, primary site, clinical stage, primary treatment, histology, the occurrence of residual or recurrent disease, salvage treatment, development of subsequent primaries, survival, and the eventual cause of death. The patient's TNM stage was reclassified according to American Joint Cancer Committee/Union Internationale Contre le Cancer (AJCC/UICC) 1992 criteria on the basis of the initial clinical description and staging investigations. A multivariate regression analysis was performed. To assess the importance of age as a prognostic factor for survival, the Cox proportion hazard model was used. Smoking status was also tested in the stratified Cox proportional hazard model. RESULTS: Tumor stage and treatment modalities were comparable in both groups. The 5-year, cause-specific survival in both groups was not statistically different (72% vs. 68%, P = .91). The young patient group had a significantly better 5-year overall survival compared with the older patient group (68% vs. 49%, P = .0011). Older patients developed more subsequent primary neoplasms than the younger patient population (18% vs. 8%, P = .005). There were significantly more females, an increased incidence of oral or oropharyngeal cancer, and fewer smokers in the young patient group. Smoking, however, had an important impact on outcome with all but one patient who developed a second primary in the upper aerodigestive tract having smoked. Multivariate analysis showed that only disease stage and cancer site were significant prognostic factors for survival. CONCLUSIONS: Young patients with HNSCC do not have a worse prognosis than a matched older patient group in this case-controlled study (power > 0.75 for a minimal detectable difference of 10% disease-free survival between the two groups).

Adult↗
PubMed1999

Effects of medialization laryngoplasty on airway resistance: a pilot study.

OBJECTIVE: To investigate the effects of medialization laryngoplasty on laryngeal airway resistance at various clinically relevant flow rates. STUDY DESIGN: This study was conducted using a total of 13 laboratory experiments. Two of the experiments were used to validate the cadaveric model employed. Eleven experiments were used to quantify airway resistance relative to increasing medialization laryngoplasty stent size. METHODS: With autopsy consent the authors obtained 13 consecutive and anatomically complete larynges for experimentation. A thyrotomy window measuring 8 x 6 mm was made on the left side of the thyroid cartilage. A #4 laryngeal mask was secured to the pharyngeal airway with sutures. Eleven experiments were conducted at the same flow rates using increasingly larger stents from 1 mm to 11 mm in size. Using the Bernoulli equation, the pressure measured at the proximal end of the laryngeal mask is representative of the pressure drop across the airway. The experimental model was validated in two experiments using flow rates between 5 and 50 L/min and stents measured at 5, 10, 15, and 20 mm. RESULTS: Average results from the 11 experiments indicate that at increasing levels of medialization, from 0 to 11 mm, there is essentially the same pressure drop across the larynx at a given flow rate. CONCLUSION: At physiologic airflow rates in a cadaveric model, medialization laryngoplasty implants of 11 mm or less seem to have no obvious effect on airway resistance.

Aged↗
PubMed1999

A retrospective comparison of the morbidity and cost of different reconstructive strategies in oral and oropharyngeal carcinoma.

PURPOSE: Evaluate and compare the morbidity and costs of different reconstructive strategies in oral and oropharyngeal carcinoma. STUDY DESIGN: Retrospective cross-sectional. PATIENTS AND METHODS: One hundred twenty-seven consecutive patients treated surgically for oral and oropharyngeal carcinoma between 1990 and 1996 were evaluated. Sixty-three patients had segmental mandibulectomies with 30 plate-soft tissue reconstructions and 33 bone-soft tissue flaps. Sixty-four patients had soft-tissue-only reconstructions. The following outcome parameters were analyzed: operative time, intraoperative blood loss, postoperative admission length, ICU and coronary care unit admission length, surgical interventions for complications, re-admissions, and prolonged (>6 mo) gastrostomy tube feeding, and all costs within the disease-free interval. Means and standard deviations were calculated for continuous parameters. Differences among the three groups were analyzed using one-way analysis of variance. For discontinuous parameters, the chi-square test was applied. RESULTS: Longer operative time (1.8 h) and more blood loss (150 mL) for bone-soft tissue flaps were the only statistically significant findings (P<.05) between the three groups. CONCLUSION: There is no rationale for allowing presumed factors of morbidity or cost select for type of reconstruction in patients with oral and oropharyngeal carcinoma.

Adult↗
PubMed1998

Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction.

BACKGROUND: The incidence of internal jugular vein thrombosis (IJVT) following a modified neck dissection remains uncertain. The effect of, or consequences following, IJVT upon pedicled and free flap head and neck reconstructions remains unexplored. METHODS: Twenty-nine preserved internal jugular veins in 24 patients undergoing modified neck dissection were available for prospective study. All patients required a pedicled or free flap reconstruction and received a modified, unilateral or bilateral cervical lymphadenectomy. The patency of all jugular veins was determined preoperatively and postoperatively using a combination of computed tomography (CT) scanning, high-resolution ultrasound, and color-flow Doppler (CFD). RESULTS: The IJVT rate was 14%. The presence of a pedicled myocutaneous flap and left-sided jugular dissections may represent risks to the postoperative patency of the internal jugular vein. Preoperative radiotherapy did not appear to impact negatively upon the thrombosis rate. CONCLUSIONS: Thrombosis of the internal jugular vein may result in significant morbidity for the postoperative oncologic patient. An internal jugular-dependent-free-tissue transfer may risk venous compromise of the flap, whereas the use of a pedicled flap may place the jugular at increased risk for thrombosis. Strategies for deep venous system microvascular recipient recruitment in the head and neck are discussed. Wherever possible, we employ two deep venous systems, the internal jugular, and subclavian (via the external jugular) for flap drainage.

Aged↗
PubMed1998

The physiologic reservoir of Epstein-Barr virus does not map to upper aerodigestive tissues.

The human Epstein-Barr herpesvirus (EBV) has distinct oncogenic potential, but with over 90% of the adult world population infected, malignancy is a rare outcome of carrier status. However, EBV's association with over half of Hodgkin's and non-Hodgkin's lymphomas as well as several solid tumors, notably nasopharyngeal carcinoma, makes EBV-linked malignancies one of the largest single cancer entities. EBV is a B-lymphotropic virus, well controlled by surveillant T cells in immunocompetent hosts. To determine the presence and site of principal virus reservoirs is a likely prerequisite for understanding the etiology of EBV-associated tumors. Its near 100% association with nasopharyngeal carcinoma led to postulates that the upper aerodigestive tract tissue may be common sites of persistent latent or low-grade replicating infection. Using a protocol designed to avoid viral crosscontamination, the authors employed polymerase chain reaction to detect genomic EBV DNA sequences in 231 biopsies from different mucosal sites in the upper aerodigestive tract, as well as from salivary gland tissue and neck nodes in individuals not suspected to have EBV-related malignancy. Only two samples, one from oral cavity mucosa and one from parotid gland tissue, were positive for EBV. The observation that oropharyngeal tissue is not the principal EBV reservoir has mechanistic implications for the development of EBV-positive tumors in that locale.

Adolescent↗
PubMed1998

An objective analysis of the impact of lateral rhinotomy and medial maxillectomy on nasal airway function.

OBJECTIVE: The lateral rhinotomy and medial maxillectomy procedure, while known to interrupt nasal valve supports, has not previously been reported to adversely affect nasal airway function. The purpose of this study was to utilize state-of-the-art techniques to objectively analyze the impact of this procedure on nasal airway function. DESIGN: The study design was retrospective and subject controlled. METHODS: The study population was derived from an academic, tertiary-referral, otolaryngology-head and neck surgery department with an estimated catchment population of 4 million people. Subjects included 21 consecutive, long-term postoperative patients who had undergone lateral rhinotomy and medial maxillectomy for inverted papilloma. Objective measures included vestibular cephalometric measurements, airflow rhinomanometry, and acoustic rhinometry. RESULTS: Statistically significant results reveal that although lateral rhinotomy and medial maxillectomy are associated with alar collapse, both overall nasal airflow and valve areas are increased. CONCLUSION: Lateral rhinotomy and medial maxillectomy does not adversely affect nasal airway function. This appears to be the result of concomitant resection of the functionally dominant inferior turbinate. This suggests that lateral rhinotomy performed in conjunction with operations not requiring inferior turbinectomy, such as anterior craniofacial resection, may adversely affect nasal airway function.

Acoustics↗
PubMed1998

Pharyngocutaneous fistulae in laryngectomy patients: the Toronto Hospital experience.

OBJECTIVE: The purpose of this study was to determine the rate of post-laryngectomy pharyngocutaneous fistulae and its association with age, gender, preoperative radiation, TNM staging, patients comorbidity factors, choice of ablation, choice of reconstruction, modality of postoperative feeding, and whether or not a primary tracheoesophageal puncture was performed. DESIGN: Retrospective clinical study. SETTING: The Toronto Hospital/Princess Margaret Hospital, University of Toronto, Toronto, Ontario. METHOD: One hundred and twenty-five consecutive laryngectomy procedures performed between July 1, 1992, and October 1, 1996, were reviewed. RESULTS: There was an overall fistula rate of 22%. No association found was between fistula rates and age, gender, patient comorbidity factors, TNM stage, choice of ablation, choice of reconstruction, modality of postoperative feeding, or whether a primary tracheoesophageal puncture was performed or not. CONCLUSIONS: At this tertiary care head and neck oncology centre, pharyngocutaneous fistulae remain an unpredictable and serious complication with an estimated economic cost of Cdn $400,000 per year.

Adult↗
PubMed1998

Adult epiglottitis: the Toronto Hospital experience.

OBJECTIVE: This study was conducted to gain insight into the diagnosis, treatment, and outcome measures in adult patients presenting with acute epiglottitis. METHOD: A retrospective clinical study was conducted on fifty-seven consecutive adult patients presenting with acute epiglottitis over a 13-year period to The Toronto Hospital, University of Toronto. Demographic description of patient population, presenting symptoms and signs, investigations performed, treatment provided, and incidence of complications were described. RESULTS: Soft-tissue lateral neck x-rays were abnormal in 88.1% of patients tested but had a 12% false-negative rate. Indirect, direct, or flexible laryngoscopy were the most accurate investigations to establish diagnosis and were not associated with any complications. Four of 45 patients (8.9%) had positive blood cultures for Haemophilus influenzae, with the remainder demonstrating no growth, while 22% of patients (8/36) grew possible pathogenic organisms on throat culture. A rapid clinical course (< 12 hr), evidence of tachycardia, or positive pharyngeal or blood cultures were factors that selected for a group of patients requiring formal airway intervention. CONCLUSIONS: Adult epiglottitis is different from its paediatric counterpart in that organism identification is less common, the clinical course is more gradual, there is less seasonal variation, airway compromise is more uncommon, and conservative airway management can be contemplated in the selected patient. Adult epiglottitis can be managed safely with a selective approach to airway management with airway intervention for any patient with signs of critical airway compromise.

Acute Disease↗
PubMed1997

Oromandibular reconstruction with the fibular free flap. Analysis of 50 consecutive flaps.

OBJECTIVE: To evaluate the results and functional outcome associated with fibular free flap reconstruction of orofacial and mandibular defects. DESIGN: We conducted a retrospective analysis of 50 consecutive fibular free flaps during a 3-year period. Forty patients were available for follow-up, which ranged from 4 to 39 months. SETTING: Academic tertiary care referral medical center. PATIENTS: Fifty consecutive mandibular reconstructions using the fibular free flap were performed on 47 patients. Thirty-five patients (74%) underwent primary reconstruction. Sixty-six percent of the mandibular defects were anterior or combined anterolateral types; the remainder were pure lateral defects. In 38 patients (81%), a skin paddle was included with the flap to provide either a mucosal lining or skin cover, whereas in only 9 patients (19%), bone was used alone. MAIN OUTCOME MEASURES: Factors reflecting functional properties and processes as well as complications of the upper aerodigestive tract were evaluated clinically and radiographically. RESULTS: Four flaps required reexploration as emergencies, and none were successfully salvaged (8.5% failure). Three patients underwent further free vascularized fibula transfer with 1 failure. During follow-up, swallowing was normal in 25 patients (64%), oral continence was normal or almost normal in 26 patients (67%), and speech was normal or easily intelligible in 35 patients (90%). Aesthetic results were excellent or acceptable in 37 patients (95%). CONCLUSIONS: Our results reveal that the vascularized fibular free flap is very suitable with an excellent success rate for reconstructing both the composite or simple long-spanned mandibular defect. The overlying skin island is reliable and provides lining or coverage for intraoral and extraoral defects. Superior functional cosmetic results are expected in the majority of patients, while donor site morbidity is minimal.

Adult↗
PubMed1997

Squamous cell carcinomas of the head and neck cultured in floating collagen gels: 1. The maintenance of stromal and epithelial elements in vitro without fibroblast overgrowth.

The study of the molecular biology of head and neck squamous cell carcinomas has been heavily reliant on the analysis of cell lines. This is largely because the maintenance of primary cell cultures is difficult. However, being monoclonal, cell lines are not representative of the primary tumor because of the loss of tumor cell heterogeneity. We report a technique for primary culture of squamous cell carcinomas with maintenance of epithelial and stromal cell components without overgrowth of the fibroblast cells. Phenotypic markers for fibroblasts and squamous cells were present up to 45 days after initiation of culture, and expression of epidermal growth factor receptor and involucrin in cultures paralleled that in the primary tumor. In vivo, tumor stromal elements are thought to play an important role in the support of epithelial cell growth. In the collagen gel system the preservation of the stromal cell component likely improves culture viability and growth. More importantly, this culture system allows the in vitro tumor to more accurately reflect the tumor from which it was derived, and it permits the study of primary squamous cell carcinomas under in vitro conditions.

Antibodies, Monoclonal↗
PubMed1997

Penetrating and blunt neck trauma: 10-year review of a Canadian experience.

OBJECTIVES: To determine if selective management of blunt and penetrating neck trauma is still appropriate in Canadian tertiary care centres because of differences in trauma demographics. A key secondary objective was a descriptive analysis of the Canadian head and neck trauma patient population and outcomes. DESIGN: A retrospective case series. SETTING: An academic tertiary care centre. PATIENTS: All 85 patients admitted between 1982 and 1992 with a diagnosis of blunt (19) or penetrating (66) neck trauma. INTERVENTIONS: Emergent neck explorations (29 patients), selective nonoperative management (20 patients) and elective neck exploration (17 patients). MAIN OUTCOME MEASURES: Hospital stay, complication rate, rate of negative exploration (elective management, emergent exploration) and rate of secondary exploration (selective management), and outcome and complication rate. The entire population was described demographically. RESULTS: In 66 patients the injuries were penetrating, with the majority being of low kinetic energy. The patients who underwent elective mandatory exploration were comparable to those who underwent selective nonoperative management. The length of stay in hospital for the selective group was significantly less (p = 0.0008), and no patient in this group required later operative management of a missed injury. However, 41% of patients who underwent elective mandatory neck exploration had no significant injury. The complication rate in the two groups was similar. CONCLUSIONS: The patients managed selectively had no difference in outcome from those who underwent mandatory elective exploration. In Canada, because of the lower incidence of high-morbidity zone I and zone III injuries and the high incidence of low kinetic energy trauma with a predilection to zone II, the surgeon may consider a selective approach where appropriate.

Adolescent↗
PubMed1997

Informed consent in head and neck surgery: how much do patients actually remember?

OBJECTIVE: This study was conducted to evaluate the effectiveness of informed consent in head and neck surgery by testing patient recall of potential complications from thyroidectomy, parathyroidectomy, and parotidectomy. DESIGN: A prospective design was used. SETTING: The setting was an academic tertiary care centre. METHODS: Fifty-four patients undergoing thyroidectomy, parathyroidectomy, or parotidectomy were consented by verbal contact by the operating surgeon with a specific preoperative checklist of complication and side effects. One week to 2 months after consent, the patients were surveyed for recall of potential complications. MAIN OUTCOME MEASURES: Rate of recall was related to various parameters including patient age, sex, level of education, occupation, and length of time from the consent interview to the recall interview. RESULTS: The overall recall rate for all procedures was 48%. Those patients who recalled over 50% of the complications were younger (p = .04) and better educated (p = .04). The gender of the patients did not appear to influence recall success (p = 1.00), even when facial scar or paralysis was considered. CONCLUSION: A significant relationship exists between education level and patient age and the rate of patient recall of potential complications of surgery.

Adult↗
PubMed1996

Effects of botulinum toxin type A injections on aerodynamic measures of spasmodic dysphonia.

The effects of botulinum toxin type A (BOTOX) injections on aerodynamic measures of phonation were examined in 30 patients with adductor spasmodic dysphonia. Patients received bilateral injections of 2.5 U of botulinum toxin type A in each thyroarytenoid muscle. Measures of air pressure, average airflow, coefficient of variation (CV) of airflow, and laryngeal resistance were obtained before the injections and at 2 and 10 weeks after the injections. These measures were also obtained from 12 normal subjects. Compared with normal subjects, the spasmodic dysphonia patients had significantly higher preinjection values for air pressure, CV of airflow, and laryngeal resistance. At 2 and 10 weeks after the botulinum toxin type A injections, the spasmodic dysphonia patients showed a significant increase in the average airflow values and a significant decrease in the CV of airflow values and the laryngeal resistance values. At 10 weeks after the injections, the values for the three measures began to approach the preinjection values. It is concluded that these aerodynamic measures of phonation can provide useful measures of treatment outcome in adductor spasmodic dysphonia.

Adult↗
PubMed1996

Prospective study of patients' subjective responses to botulinum toxin injection for spasmodic dysphonia.

Adductor spasmodic dysphonia (SD) is a speech disorder resulting from involuntary contractions of the laryngeal muscles. Botulinum toxin (BT) injection of the thyroarytenoid muscle is an effective, though temporary, treatment for most SD patients. Though there are reports of objective improvements in voice quality, there are no large studies of patients' subjective responses to treatment over time. In the present study, patients were given voice diaries to rate vocal spasms, hoarseness, breathiness, volume problems, and dysphagia before and the after treatment. Analysis of these diaries revealed that: (1) most side effects had resolved 4 to 6 weeks after injection, whereas vocal spasm relief persisted; (2) vocal spasm relief and severity of side effects peaked within 1 week; and (3) unilateral injections, though as effective in relieving vocal spasms, caused less volume and swallowing problems than did bilateral injections.

Adult↗