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Biomedical subjects

K H Lam

Publications and source records attributed to K H Lam.

At least 73 records · Page 4Linked to original sources
PubMed1987

Present status of pharyngogastric anastomosis following pharyngolaryngo-oesophagectomy.

Pharyngolaryngo-oesophagectomy with pharyngogastric anastomosis was described more than 25 years ago. Since then it has been employed for the treatment of cancers of the hypopharynx, cervical oesophagus and larynx. Results of recent reports showed a wide variability. Our previous report of 157 such operations gave a significant morbidity and overall hospital mortality rate of 31 per cent. In the 6-year period between 1980 and 1985, 91 patients underwent this operation. The morbidity and mortality rates gradually decreased to 30 and 5 per cent respectively. Changes in the indications for the operation resulted in a reduction in the number of procedures performed in recent years. Resection of the oesophagus for cancers of the pharyngolaryngeal region is indicated only when there is actual oesophageal involvement, and would be the prime indication of pharyngogastric anastomosis.

Esophageal Neoplasms↗
PubMed1987

Reconstruction of hypopharyngeal defects in cancer surgery: do we have a choice?

Between 1982 and 1985, 83 patients with hypopharyngeal or extensive laryngeal cancers underwent pharyngoesophagectomy (48 patients), circumferential pharyngectomy (8 patients), and partial pharyngectomy (27 patients), depending on the site and extent of tumor involvement. The resultant hypopharyngeal defects were reconstructed with gastric transposition, a tubed pectoralis major myocutaneous flap, and a pectoralis major flap patch, respectively. There were three hospital deaths in the gastric transposition group (6 percent) and none in both pectoralis major flap groups. The leakage rate was 8.3 percent in the gastric transposition group, 25 percent in the tubed pectoralis major flap group, and 3.7 percent in the pectoralis major flap patch group. Stricture was avoided with the interdigitation technique used at the tubed-flap-to-esophagus anastomosis, although the fistula rate was high. The overall complication rate was higher with gastric transposition. Although swallowing was satisfactory in all three groups, 42 percent of the patients with gastric transposition experienced regurgitation. Over a follow-up period of 16 to 50 months the local recurrence rate was 5 percent, and the actuarial survival rate was 55 percent at 24 months.

Anastomosis, Surgical↗
PubMed1987

Healing between cartilage and bone ends. An experimental study.

Whether healing or nonunion occurs at the junction between cartilage and bone was studied in an animal experimental model. The costochondral junctions of the floating ribs of rabbits were excised and the cut ends of bone and cartilage reapproximated with wire. The process of healing was then observed. Fibrocartilaginous callus formed in the first week. Beginning in the second week, this was gradually replaced by bony callus, a process which started from the medullary cavity of the bone end. The cut end of the original cartilage showed no activity. The periosteum and perichondrium became continuous at 4 weeks. The site of ossification assumed the appearance of the original costochondral junction. The gap between the original cartilage and the new cartilage disappeared when fusion occurred at 48 weeks. Osteochondral junctions at various periods after operation were subjected to disruption force until the junctions were pulled apart. The average force required to break 16 junctions was 2,738 g, and was not related to the period of healing.

Animals↗
PubMed1987

Entering the pharynx in total laryngectomy.

In performing total laryngectomy for carcinoma of the larynx, the pharynx should be entered at sites away from the tumour. When the tumour is supraglottic in location, the entry should be through the lateral pharyngeal wall; and when the tumour is located in the postcricoid area, entry above the hyoid bone is preferred.

Humans↗
PubMed1987

The role of the fibreoptic bronchoscope in otorhinolaryngological practice.

Flexible fibreoptic bronchoscope has been employed in the examination of the nasopharynx, pharynx, larynx, trachea, bronchus and intrathoracic oesophagus under local anaesthesia. It is used either for diagnostic or therapeutic purposes. A total of 1690 procedures have been performed with no complication. The indications and findings in these procedures are listed. The advantages and limitations of the use of flexible fibreoptic bronchoscope as a 'panendoscopic examination' instrument are discussed.

Adolescent↗
PubMed1987

The efficacy of myringotomy and ventilation tube insertion in middle-ear effusions in patients with nasopharyngeal carcinoma.

Myringotomy and insertion of a grommet are effective in the management of middle-ear effusion resulting from nasopharyngeal carcinoma. The procedure was carried out in 46 ears in 30 patients, resulting in significant improvement of hearing. The complication rate of the operative procedure is not negligible in this group of patients, and it is higher if the patients had received radiotherapy at the time of operation.

Adult↗
PubMed1986

Parapharyngeal space tumours.

Tumours in the parapharyngeal space have been difficult diagnostic and management problems. Consideration of the anatomy in three dimensions may be illustrated with computed tomography. Fifteen patients with parapharyngeal space tumours are presented, including six salivary gland tumours, four neurogenic tumours and five tumours from miscellaneous origin. The tumours were all treated by surgical excision. The preferred approach was the transcervical route. Additional procedures, including total conservative parotidectomy, were carried out depending on the pathology. Mandibulotomy was required for only one patient whose tumour had infiltrated the base of the skull and extended intracranially.

Adenoma↗
PubMed1986

Tumours of the parotid--the value of clinical assessment.

A series of 131 tumours of the parotid was reviewed retrospectively to ascertain the value of clinical features in distinguishing between malignant and benign tumours. The overall proportion of malignancy in this group of tumours was 17% (23 tumours). It was found that sex, age, size, duration of symptoms, and history of rapid enlargement were non-contributory to a diagnosis of malignancy, while the presence of facial nerve paralysis, skin infiltration or ulceration, and metastatic neck nodes were found only in patients with malignant tumours. A history of pain, hardness, and fixity, found in 30-50% of parotid cancers, were significant indicators of malignancy. As the yield of routine frozen section examination on all resected parotid tumours is low, it is recommended that if resources are limited, the examination be reserved for tumours highly suspicious of being malignant.

Biopsy↗
PubMed1986

Prospective screening for multiple tumors of the upper aerodigestive tract: a simple routine procedure.

Detection of a second primary at the time of initial work-up of patients with head and neck cancers has an important bearing on management planning. In a 12-month period, a series of 105 patients with an index head and neck primary (skin malignancies excluded) of the squamous cell type were subjected to the following screening procedure. Under topical anesthesia, with the patient in the sitting position, a small-size flexible bronchofiberscope (Olympus B3R) was introduced through the nose. As the scope was advanced, the nasal cavity, nasopharynx, oropharynx, hypopharynx, and larynx were examined. The tracheobronchial tree was also examined if the chest x-ray showed abnormal findings. The endoscope was then passed down to examine the esophagus, with oxygen insufflated via the biopsy channel at a rate of 1 liter per minute. The index primary sites included the tongue (20), alveolus (7), floor of mouth (2), palate (4), buccal mucosa (3), hypopharynx (17), and larynx (52). There was little patient discomfort and no complication. Nine patients (8.5%) were found to have simultaneous primary tumors including two patients with triple primaries and one with quadruple lesions. The additional tumors were in the following sites: esophagus (6), tonsil (2), floor of mouth (1), nasopharynx (1), bronchus (1), palate (1), and oropharynx (1). The treatment plans were changed in all nine patients with the discovery of multiple tumors. It is concluded that the panendoscopic screening in the manner described is simple, safe, and convenient and the information is contributory to treatment planning.

Adult↗
PubMed1985

Use of the pectoralis major muscle flap for repair of a tracheoesophageal fistula.

A case of tracheal rupture after a Lewis-Tanner esophagectomy in a patient with carcinoma of the esophagus was complicated by the formation of a tracheoesophageal fistula after initial direct repair. The fistula was successfully treated with a pectoralis major muscle flap moved into the superior mediastinum by a sternotomy and excision of the upper part of the sternum and adjacent costal cartilages.

Carcinoma, Squamous Cell↗
PubMed1984

Endochondral pseudocyst of the auricle in Chinese.

Thirty-one patients with endochondral pseudocysts of the auricle were seen over a four-year period in the Department of Surgery at the University of Hong Kong. The lesions chiefly affected Chinese males (90.3%); 80.6% involved the scaphoid fossa on the anterior surface of the pinna. They were usually asymptomatic and static in size. Excision of the anterior wall, followed by contour pressure dressing, gave cosmetically satisfactory results in 90% of the patients, and there were no recurrences. Pathologic studies revealed the absence of an epithelial lining as well as multiple cystic spaces that contained abundant glycosaminoglycans (acid mucopolysaccharides). We postulate that the overproduction of glycosaminoglycans engendered by repeated minor trauma to the cartilage was the primary cause of the pseudocysts.

Adult↗
PubMed1984

Bronchoscopy and carcinoma of the esophagus I. Findings of bronchoscopy in carcinoma of the esophagus.

Tracheobronchial involvement frequently occurs in patients with carcinoma of the esophagus. A study of the results of 525 bronchoscopies performed on patients with carcinoma of the esophagus who were evaluated for surgery revealed that abnormalities were found in 33.9 percent. The incidence was highest for those with cervical and upper-third thoracic tumors; however, a significant number of lower-third thoracic and abdominal tumors also showed abnormalities (12.5 and 5 percent, respectively). The incidence was also higher with large tumors, but again, a significant number of apparently small tumors also showed abnormalities. The abnormalities could be broadly classified into two groups: those showing only impingement and those showing actual invasion. Further studies are needed to determine whether the tumors with impingement are resectable.

Adult↗
PubMed1984

Bronchoscopy and carcinoma of the esophagus II. Carcinoma of the esophagus with tracheobronchial involvement.

Involvement of the tracheobronchial tree, as observed through the bronchoscope, was in the form of impingement or invasion. Bronchoscopy was performed on 525 patients with carcinoma of the esophagus. Impingement was found in 91 patients and invasion in 87 patients. Forty-eight of the 63 patients with impingement and 7 of the 51 patients with invasion were found to have resectable tumors. Bypass operations were performed on the rest of the patients. The operative mortality was high for both bypass and resection procedures. The median survival for bypassed patients and resected patients were 4 months and 9 months, respectively. Four resected patients survived 3 years or more, 2 of whom had no evidence of recurrence. Most patients with impingement have resectable tumors and long-term survival is possible if the tumor can be resected.

Adult↗
PubMed1984

Late problems after pharyngolaryngoesophagectomy and pharyngogastric anastomosis for cancer of the larynx and hypopharynx.

The late problems of 136 patients who had undergone pharyngolaryngoesophagectomy and pharyngogastric anastomosis were studied. The proportions of patients who required long-term thyroxine supplementation were 67 percent, 13 percent, and 5.3 percent of the patients who had total thyroidectomy, hemithyroidectomy, and no thyroidectomy, respectively. The proportions of patients who required calcium and vitamin D supplementation were 67 percent, 23 percent, and 17 percent, respectively. Speech rehabilitation was unsatisfactory. Alimentary functions were satisfactory in that the majority of patients were able to take in solid food. Although a sensation of obstruction of food was occasionally felt, no organic abnormality was found in any patient. Regurgitation was noted in 23 percent of the patients, and hematemesis was an occasional symptom of gastritis or gastric ulcer, although symptomatic gastric ulcer was found in only two patients. It is concluded that the long-term morbidity after this extensive procedure is mild and acceptable. The operation is recommendable for extensive tumors of the laryngopharyngeal region.

Adult↗
PubMed1984

The true pectoralis major myocutaneous island flap: an anatomical study.

The pattern of blood supply to the clavicular and sternocostal portions of the pectoralis major muscle was studied in the cadaver with X-rays of injected specimens. The major blood supply to the sternocostal part was derived from the pectoral branch, although in about 50% of cases the clavicular branch provided minor contributions. This finding supports the clinical experience that it is safe to isolate the full length of the vascular pedicle, deep to the clavicular portion of the muscle, in the preparation of a pectoralis major myocutaneous flap.

Humans↗
PubMed1984

The pectoralis major costomyocutaneous flap for mandibular reconstruction.

In this paper we present a series of 14 pectoralis major costomyocutaneous flaps employed on patients who required mandibulectomy for oral tumors. Experience with this previously described technique is analyzed and its complications are presented. Although the pectoralis major muscle does not originate from the ribs, there appears to be enough blood supply by means of the delicate areolar connections and the periosteum to sustain the costal segment. In an attempt to improve the blood supply by means of the perichondrium, we have included a portion of the costal cartilage. In our series there were three failures resulting probably from technical errors. Apart from these, the results were satisfactory. However, the use of this procedure is relatively recent, and its long-term results are unknown at the moment.

Adolescent↗