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Biomedical subjects

C J O'Brien

Publications and source records attributed to C J O'Brien.

At least 37 records · Page 2Linked to original sources
PubMed1998

Parotid and submandibular sialadenitis treated by salivary gland excision.

BACKGROUND: The purpose of the present study was to compare and contrast the clinicopathological features and treatment outcome of chronic sialadenitis involving the parotid and submandibular glands, among patients who were treated by excision of the affected gland. METHODS: In a series of 88 patients treated over an 8-year period, 47 had parotid sialadenitis and 41 had submandibular sialadenitis. In the parotid group, 63% of patients were symptomatic for longer than 6 months compared with 27% in the submandibular group. Calculi were implicated in the disease process in 24% of patients with parotid sialadenitis, compared with 73% of patients with submandibular disease. RESULTS: Patients with parotid sialadenitis had superficial (n = 14) or near-total parotidectomy (n = 35), while those with submandibular sialadenitis underwent total gland excision. Complications occurred twice as frequently in the parotidectomy group. The rate of temporary facial nerve weakness was 29% after parotidectomy while marginal mandibular nerve dysfunction occurred after 12% of submandibular excisions. Both procedures were highly effective in permanently relieving the symptoms of sialadenitis. CONCLUSIONS: Parotid sialadenitis is infrequently associated with stones and tends to run a longer course before surgical intervention is necessary. Submandibular sialadenitis usually presents earlier, is secondary to calculi and requires early intervention.

Chronic Disease↗
PubMed1998

Role of the endothelium in modulating functional responses of isolated bovine anterior ciliary arteries to vasoconstrictor agonists.

BACKGROUND/AIMS: Endothelium dependent vasodilatation is an important regulator of blood flow to the eye but its role has not been investigated in vessels supplying the ciliary body. This study assessed the role of the endothelium in modulating vasoconstrictor responses of the intraocular bovine anterior ciliary artery. METHODS: Bovine anterior ciliary arteries (n = 33) were mounted in a myograph, containing physiological salt solution at 37 degrees C, for isometric force measurement. Cumulative concentration-response curves were obtained to the constrictor agonists 5-hydroxytryptamine (5-HT), noradrenaline, phenylephrine, prostaglandin, F2 alpha, endothelin-1, and KCl in both endothelium intact and denuded arteries. RESULTS: All vasoconstrictors produced sustained contractile responses which were unaffected by the removal of the endothelium. Responses to 5-HT were also unaffected by inhibition of nitric oxide synthase. CONCLUSION: These results indicate that neither agonist stimulated nor basal release of nitric oxide from the endothelium modulates responses to vasoconstrictor agonists in the isolated bovine anterior ciliary artery when measured in a no flow isometric system.

Animals↗
PubMed1997

Facial nerve function after parotidectomy.

OBJECTIVES: To analyze the incidence of facial nerve dysfunction following parotidectomy and to correlate this with the extent of parotid gland resection, the pathological diagnosis, and the clinical setting. DESIGN: A review of prospectively collected data from a dedicated computerized head and neck database. SETTING: Tertiary care center. PATIENTS: Between 1987 and 1995, 248 patients underwent 259 parotidectomies performed by the same surgeon (C.J.O'B.). Indications were clinical tumor (n=213) or sialadenitis (n=46). There were 235 previously untreated patients and 13 who had undergone a prior operation on that side. Facial nerve function was normal in 242 patients and abnormal before surgery in 6. Cancers accounted for 88 parotidectomies and benign disease accounted for 171. Of 213 clinical tumors, 41 (19%) were situated deep to the plane of the facial nerve. RESULTS: The facial nerve was intentionally sacrificed in 28 of 259 operations (18 total and 10 partial sacrifice). In 230 parotidectomies in which facial nerve function was normal before surgery and the nerve was preserved, the incidence of initial postoperative facial weakness was 29%. Based on the diagnosis and extent of surgery, rates of facial weakness were 16.5% and 13%, respectively, for benign and malignant tumors located in the superficial lobe and treated with limited superficial parotidectomy; 30% and 34% for sialadenitis treated with complete superficial parotidectomy and near-total parotidectomy, respectively; 31% and 100%, respectively, for benign and malignant lobe tumors treated with near-total parotidectomy; 83% for parotidectomy associated with a neck dissection; and 33% for patients who had previous parotid surgery. Permanent weakness occurred in 13 (5.6%) of 230 patients, but 10 of these 13 had simultaneous neck dissection and facial nerve dysfunction involved only the marginal mandibular branch. Recovery of normal facial movements occurred within 6 months in 46 (68%) of 67 of those with initial weakness. CONCLUSIONS: The likelihood of temporary facial weakness correlated with the extent of surgery and was especially influenced by tumor location deep to the plane of the facial nerve, previous parotid surgery, a diagnosis of sialadenitis, and the addition of neck dissection to the parotidectomy. Permanent weakness mainly affected the marginal mandibular branch when neck dissection was included.

Adolescent↗
PubMed1997

Adjuvant radiotherapy following neck dissection and parotidectomy for metastatic malignant melanoma.

BACKGROUND: Regional recurrence remains a problem in the management of patients with metastatic malignant melanoma in the cervical lymph nodes and parotid. In this study, the influence of the number of positive nodes, extracapsular spread, and the use of adjuvant radiotherapy on regional control and survival were analyzed. METHODS: A non-randomized, prospectively documented series of 143 patients with histologically positive nodes in the neck or parotid was analyzed. There were 152 dissected necks or parotids: 45 of these received postoperative radiotherapy, 6 x 5.5 Gy fractions over 3 weeks; 107 were not irradiated. RESULTS: The regional recurrence rate was 6.5% in the irradiated group, compared with 18.7% in the non-irradiated group (p = .055). The irradiated group, however, had more extensive nodal involvement than the non-irradiated group: 65% had two or more positive nodes, and 48% had extracapsular spread, compared with 40% and 19%, respectively, in the non-irradiated group. Survival was significantly worse when there was extracapsular spread (p < .05) or multiple node involvement (p < .01). By multivariate analysis, the use of adjuvant radiotherapy was associated with a trend toward improved regional control (p = .065), but survival was not improved. CONCLUSIONS: Adjuvant radiotherapy was associated with improved control of metastatic malignant melanoma in the neck and parotid; however, statistical significance was not reached. A prospective trial should be supported to clarify this question.

Female↗
PubMed1996

Image-guided core biopsy in patients with breast disease.

Ultrasonographically-guided core biopsy has been used as an adjunct to triple assessment when fine-needle aspiration cytology was inadequate or equivocal, if the overall assessment of the patient was uncertain, or if it was deemed the preferred diagnostic option. Some 143 of 2603 patients had a guided core biopsy, 125 to establish the diagnosis and 18 to obtain histology in cytologically proven malignancy. A diagnosis of malignancy was established in 43 of the 125 patients who had a diagnostic core biopsy. Some 45 patients with benign disease were either discharged or returned to follow-up on the basis of the core biopsy. The remaining 37 patients required surgical biopsy, of whom 13 had malignant and 24 benign disease. The overall positive predictive value for malignancy was 98 per cent. Experience with ultrasonographically-guided core biopsy shows that it can reduce the need for surgical biopsy in both benign and malignant conditions of the breast.

Biopsy, Needle↗
PubMed1995

Parotid and neck metastases from cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: Approximately 5% of cutaneous squamous cell carcinomas (SCC) metastasize to regional nodes. Nodal involvement may be more common for cutaneous squamous cell carcinomas of the head and neck, but few large series have reported clinical outcome after treatment of parotid gland and neck metastases from these cancers. PATIENTS AND METHODS: A combined retrospective/prospective study of patients treated between 1983 and 1994 was performed. There were 69 men and 6 women, with a median age of 67 years. Twenty-nine patients had neck metastases, and 33 had parotid gland metastases, while 13 patients had involvement at both sites. Of the 75 patients, 68 were treated surgically and 50 received postoperative radiotherapy. RESULTS: The facial nerve was sacrificed totally in 6 patients and partially in 9. Histologic extranodal spread was present in 48 (71%) of all surgically treated patients. Among 61 patients followed up to recurrence, or for greater than 12 months, 26 (43%) developed recurrence--12 in the parotid gland, 7 in the neck, and 7 in both sites. Multiple recurrences were common and occurred at a median of 8 months after surgery. Positive surgical margins were associated with poorer local disease control (P < 0.05). Cumulative survival at 5 years was 61%, but only 15 of 70 evaluable patients (21%) were eligible for follow-up at this time. Neck involvement with or without parotid gland disease was associated with an increased risk of distant metastases, but this was not statistically significant. Postoperative radiotherapy was not associated with improved disease control. CONCLUSION: Cutaneous, metastatic SCC involving the parotid gland and neck is an aggressive disease with a tendency to an infiltrative growth pattern and multiple recurrences. More aggressive surgery may be justified to reduce the incidence of regional failure after parotidectomy and neck dissection.

Adult↗
PubMed1995

Prediction of potential metastatic sites in cutaneous head and neck melanoma using lymphoscintigraphy.

BACKGROUND: The technique of lymphoscintigraphy may allow a more selective approach to the management of clinically negative neck nodes among patients with cutaneous head and neck melanoma. PATIENTS AND METHODS: A group of 97 patients with cutaneous head and neck melanoma had preoperative lymphoscintigraphy using intradermal injections of technetium 99m antimony trisulfide colloid to identify sentinel nodes. Fifty-one patients were eligible for clinical analysis after initial definitive treatment by wide excision only (n = 11), wide excision and elective dissection of the neck (n = 19) or axilla (n = 1), or wide excision and a sentinel node biopsy procedure (n = 20). RESULTS: Sentinel nodes were identified in 95 of 97 lymphoscintigrams, and 85% of patients had multiple sentinel nodes. In 21 patients (22%), sentinel nodes were identified outside the parotid region and the 5 main neck levels, mostly in postauricular nodes (n = 13). Lymphoscintigrams were discordant with clinical predictions in 33 patients (34%). Lymph nodes were positive in 4 elective dissections and 4 sentinel node biopsies. Among 16 patients evaluable after wide excision and a negative sentinel node biopsy, 4 patients subsequently developed metastatic nodes; however, confident identification of all nodes marked as sentinel nodes on lymphoscintigraphy was not achieved at the original biopsy procedure in 3 of these patients. CONCLUSIONS: Lymphoscintigraphy and sentinel node biopsy are more difficult to perform in the head and neck than in other parts of the body. The reliability of sentinel node biopsy based on lymphoscintigraphy may be improved by identifying and marking all nodes that are considered to receive direct lymphatic drainage from the primary melanoma, and by use of a gamma probe intraoperatively.

Adolescent↗
PubMed1995

Sentinel lymph node status as an indicator of the presence of metastatic melanoma in regional lymph nodes.

The value of elective lymph node dissection (ELND) for melanoma patients with clinically uninvolved regional nodes remains controversial. However, it has been proposed that selective 'sentinel' lymph node biopsy reliably identifies individuals with micrometastases, who are most likely to benefit from full ELND. The aim of this study was to confirm that metastatic melanoma cells travelling in lymphatics do not bypass the sentinel node. After preoperative lymphoscintigraphy and intraoperative injection of blue dye around the primary melanoma site, sentinel node biopsy was performed in 118 melanoma patients for whom full ELND was planned as part of their definitive surgical treatment. A confidently identified sentinel node was tumour positive in 22 out of 105 regional lymph node fields (21%). In 18 cases the sentinel node was the only node found to be involved and in four cases, additional nodes were positive. In two other patients a positive node was found when the sentinel lymph node had been negative. However, in each case an avoidable error of technique had occurred and definite blue staining indicated that the positive node was in fact another sentinel node. This study thus confirms that sentinel lymph node status reliably indicates whether metastatic melanoma is present in regional lymph nodes.

Adolescent↗
PubMed1995

Elective lymph node dissection in patients with primary melanoma of the trunk and limbs treated at the Sydney Melanoma unit from 1960 to 1991.

BACKGROUND: The value of elective lymph node dissection (ELND) in melanoma remains controversial. Published prospective and retrospective studies can be criticized, and results from two ongoing randomized trials are not yet available. A previous retrospective review from the Sydney Melanoma Unit (SMU) showed apparent survival benefit from ELND, especially in tumors of intermediate thickness. STUDY DESIGN: We undertook a retrospective analysis of all patients treated at the SMU since 1960 for melanoma of the trunk or limbs measuring 1.5 mm or more in thickness, without clinical lymph node metastases, whose definitive wide excision (WE) with or without ELND was performed at the SMU within 60 days of initial diagnosis. RESULTS: There were 1,278 patients who fulfilled these criteria. Of these, 845 (66 percent) were treated with ELND and the remaining 34 percent were treated with WE alone. The median follow-up period was 58 months. Patients with thicker tumors and younger age more commonly underwent ELND. Among patients with thinner tumors, males underwent ELND more commonly than females. A multivariate proportional hazard model of melanoma-specific survival stratified by tumor thickness was chosen to allow for the imbalances between the two groups. With or without allowance for covariates, no benefit from ELND was found in the whole group or any subset. In contrast to previous studies from the SMU, we deliberately excluded from the present study patients referred only after WE with or without ELND elsewhere, because these might have been a selectively biased poor prognostic group. CONCLUSIONS: This study does not indicate a benefit from ELND for melanomas of the trunk or limbs measuring over 1.5 mm in thickness.

Female↗
PubMed1994

Evaluation of 107 therapeutic and elective parotidectomies for cutaneous melanoma.

A total of 107 patients with cutaneous melanoma had parotidectomies performed by one surgeon over a 6-year period. Twenty-five parotidectomies were therapeutic and 82 were elective. All elective and 18 therapeutic operations entailed superficial lobectomy, and there were 4 total and 3 subtotal therapeutic operations. The facial nerve was completely preserved in 97 operations, partially sacrificed in 8, and totally sacrificed in 2. Neck dissection accompanied all but 1 parotidectomy. The most common postoperative complication was facial nerve dysfunction. A total of 33 of 82 patients had lower lip weakness between 6 months and 5 years after elective parotidectomy. Lymph nodes were pathologically positive in the parotid gland in 27 patients and in the neck in 15 patients. Ten patients had both parotid and neck metastases. Among patients with positive melanoma in the parotid gland who were observed for at least 1 year, 16 received adjuvant postoperative radiotherapy (550 cGy x 5 fractions) and 9 did not. Parotid recurrences developed in 1/16 irradiated and 4/9 nonirradiated patients but this difference was not significant. Overall melanoma-specific survival at 5 years was 64%, with nodal involvement in the neck or parotid gland significantly worsening prognosis (40% survival at 5 years). The roles of elective lymphadenectomy and adjuvant radiotherapy are now being examined in prospective randomized clinical trials.

Elective Surgical Procedures↗
PubMed1994

Advanced patient age should not preclude the use of free-flap reconstruction for head and neck cancer.

BACKGROUND: Microvascular free flaps have become the principal form of reconstruction after the radical excision of head and neck malignancies at Royal Prince Alfred Hospital, Sydney. This surgery is time consuming, complex, and may be regarded as inappropriate in some elderly patients. This paper examines whether or not elderly patients (aged 70 years and older) are unduly disadvantaged by this form of reconstruction in the management of head and neck malignancy. PATIENTS AND METHODS: Two groups of patients were retrospectively studied: 26 patients aged 70 years or older (group 1) and 91 patients aged less than 70 years (group 2). All patients had a free-flap reconstruction after radical excision of head and neck malignancies between 1987 and 1993. The anatomic distributions of cancers and clinical stages were similar in both groups. The two groups were examined for preoperative medical risk factors, postoperative complications, length of hospital stay, and ability to tolerate an oral diet. RESULTS: In group 1, 81% of patients had at least 1 preoperative risk factor, with 42% cardiac and 27% respiratory risks. In group 2, 51% of patients had preoperative risks, 11% cardiac and 22% respiratory. Postoperatively, 42% of patients in group 1 had surgical complications, versus 37% in group 2. Postoperative medical complications were 54% in group 1 and 29% in group 2. Median hospital stay was 22 and 23 days, respectively. CONCLUSION: There was no statistical difference in the postoperative surgical complication rates, and, when stratified for premorbid factors, the overall postoperative complication rates between the two groups were also not statistically significantly different. This suggests that age alone should not exclude a patient from radical surgery for head and neck cancer with free-flap repair.

Age Factors↗
PubMed1994

Lymphoscintigraphy to identify sentinel lymph nodes in patients with melanoma.

Lymphoscintigraphy (LS) has been performed for 8 years in patients of the Sydney Melanoma Unit, to define lymphatic drainage patterns. Over the past 2 years, LS has also been used to locate the sentinel lymph node prior to surgery. Our technique for LS and subsequent sentinel node biopsy has an accuracy of 97%. All sentinel nodes must be marked to ensure the successful application of the sentinel biopsy technique. We have found that the axilla and groin average just over one sentinel node per draining node group for lesions on the trunk and upper limb, but have noted that drainage to the groin differed when lower limb lesions were studied. Because of the anastomosis of lymph vessels in the upper thigh, multiple sentinel nodes are identified in the groin in some patients. We have found an average of three sentinel nodes in the groin when lymph drainage from lower limb lesions was studied with LS. This difference demands a modification of the LS technique, with early imaging of the groin nodes to identify all sentinel nodes in each patient. The depth of the sentinel nodes can also be measured and the location of all interval nodes marked on the skin. This ensures that all sentinel nodes and interval nodes can be removed at the time of surgery.

Arm↗
PubMed1994

Treatment of early carcinoma of the vocal cords by radiotherapy.

A total of 145 patients with early carcinoma of the vocal cords (T1,2N0) were treated by radiotherapy from 1979 to 1989. Survival and local control data were available for 135 and 127 patients, respectively. The respective 5 and 10 year results for overall survival were 75 and 68%. The 5 and 10 year probabilities of local control by radiotherapy were 89 and 86%, respectively, for T1 tumours and 70% at both time intervals for T2 tumours. Tumour recurrence following radiotherapy was documented in 18 of 127 patients. Tumour stage predicted significantly for local control, with recurrence rates for T1 and T2 tumours of 11 and 27%, respectively (P = 0.02). There was a higher proportion of recurrences for total radiation doses < or = 6200 cGy (17%) compared with > 6200 cGy (8%), but the difference was not statistically significant. Increasing duration of treatment was related significantly to increased recurrence for T2 (P = 0.01), but not T1, tumours. Most recurrences (60%) were salvaged successfully by laryngectomy. Three patients required laryngectomy for laryngeal oedema without recurrent tumour; all had been treated using a large field size (7 x 6 cm). There were 20 metachronous tumours, including five lung and two head and neck tumours. These results are similar to previous reports and confirm that radiotherapy is very effective for early glottic cancer, with high local control rates and effective salvage if local recurrences are recognized early.

Adult↗
PubMed1994

A selective approach to neck dissection for mucosal squamous cell carcinoma.

A personal series of 189 neck dissections performed over 6 years among 154 patients with mucosal squamous cell carcinoma is presented. The most common primary sites were the oral cavity (66), oropharynx (38) and hypopharynx (17). There were 104 therapeutic and 85 elective neck dissections. Over 40% of therapeutic dissections were modified or selective procedures. Radical neck dissection was never used electively. Seventy-eight patients (50%) had postoperative radiotherapy to the neck. Nodes were histologically positive in 110 dissections overall (58%); 92% of therapeutic dissections and 17% of elective dissections. Extracapsular spread was present in 65% of positive dissections. Ipsilateral neck recurrence developed in 10 of 60 patients who had therapeutic radical dissections (17%) and in 2 of 44 patients who had therapeutic, modified or selective dissections (5%). Recurrence after elective dissection occurred in only one patient (1.2%). It is concluded that modified and selective neck dissection are safe and oncologically effective when used among selected patients and combined with adjuvant radiotherapy. Neck recurrence may still occur among patients with advanced and biologically aggressive disease despite radical therapy.

Adult↗
PubMed1994

Flicker perimetry using a luminance threshold strategy at frequencies from 5-25 Hz in glaucoma, ocular hypertension and normal controls.

A prototype automated flicker perimeter was used to investigate flicker luminance thresholds in glaucoma patients (n = 11), ocular hypertensives (high risk n = 10, low and intermediate risk n = 21) and normal controls (n = 10). Differential light sensitivity was measured for one eye of each subject using a flickering stimulus at frequencies of 5, 10, 15, 20 and 25 Hz at ten test locations of 1 degree in the arcuate and nasal regions of the central 50 degrees of the visual field using a 4-2 dB staircase. The glaucoma patients had significantly reduced sensitivities for all frequencies (p < 0.001) with minimum sensitivity at 15 Hz. The 'high risk' ocular hypertensives had significantly reduced sensitivities at 10 and 15 Hz (p < 0.02). At present the ocular hypertensive patients in this study show no abnormalities demonstrable by conventional automated static perimetry. These findings may represent the earliest of perimetric deficits in patients with glaucomatous optic neuropathy.

Female↗