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Biomedical subjects

M O Maiwand

Publications and source records attributed to M O Maiwand.

12 recordsLinked to original sources
PubMed2004

The application of cryosurgery in the treatment of lung cancer.

Lung cancer is the commonest cause of cancer death, with a very poor survival rate. By the time of diagnosis, most cases are at an advanced stage and about 30% present with symptoms caused by central endobronchial obstruction. Endobronchial cryosurgery is an effective technique, which can be used to relieve tracheobronchial obstruction caused by lung cancer. This report describes the technique, using a nitrous oxide cooled cryoprobe, inserted through a bronchoscope, to remove the obstruction and reopen the airway. In this study, 476 consecutive patients (mean age 68.3 years, M:F ratio 1.9:1) with obstructive tracheobronchial tumours underwent a mean of 2.4 cryosurgical treatments. Their TNM staging was, stage II 6.7%, IIIa 21.0%, IIIb 23.9%, IV 48.4%. Improvement in symptom quantification was found with 76.4, 69.0, 59.2, and 42.6% of symptomatic patients for haemoptysis, cough, dyspnoea, and chest pain, respectively. Mean values for respiratory function improved from 1.38 to 1.41 litres for FEV1 and 1.91 to 2.04 litres for FVC (p </= 0.0001). Mean performance status improved from 59.6 to 75.2 for Karnofsky scale and 3.04 to 2.20 for the WHO scale and the complication rate was 3.5% of treatments. The Kaplan-Meier median survival was 8.2 months and 1- and 2-year survival 38.4 and 15.9%, respectively. Survival analysis suggested a possible survival advantage over alternative palliative techniques. Endobronchial cryosurgery provides a safe and effective method for the palliation of otherwise inoperable lung cancer. It has advantages over other methods in terms of safety, cost, and a low complication rate. Cryosurgery can be repeated as often as required.

Adult↗
PubMed2004

Cryosurgery for lung cancer: clinical results and technical aspects.

Lung carcinoma is the most frequently diagnosed malignancy in the world, with the incidence increasing through the 20th century. Presentation may be as a tumor mass primarily obstructing the central bronchial lumen, or a mass infiltrating lung tissue. Cryosurgery can be used as a method of palliative treatment for both these endobronchial and extrabronchial presentations. The aim of this study is two-fold: to present data relating to our extensive experience in treating obstructing endobronchial tumors and to present our initial results of direct cryosurgery to infiltrating lung tumor masses. During a nine-year period, 521 consecutive patients (male:female ratio 1.8:1) with a mean age of 67.9 years who had advanced obstructive tracheobronchial malignant tumors underwent cryosurgery with a mean of 2.4 treatments per patient. Hemoptysis, cough, dyspnoea and chest pain improved by at least one class in 76.4%, 69.0%, 59.25% and 42.6% (p<0.01) of symptomatic patients respectively. Quality of life studies showed that the mean Karnofsky score improved from 60 +/- 7 to 75 +/- 8 and the mean WHO score from 3.04 +/- 0.7 to 2.20 +/- 0.56. There were 7 (1.2%) in-hospital deaths, and 2-year survival was 15.9%. Direct cryosurgery to carcinoma of the lung was performed on 15 patients at exploratory thoracotomy. Results showed an increase in FEV1 from 1.80 +/- 0.6 liters to 1.95 +/- 0.8 (8.3%) liters and in FVC from 2.50 +/- 0.8 to 2.68 +/- 0.8 liters (7.2%). The Karnofsky score improved from 68 +/- 9 to 78 +/- 10 and the WHO score from 2.63 +/- 0.81 to 2.38 +/- 0.78 (9.6%). Major symptoms including cough, dyspnoea, and hemoptysis were assessed and showed improvement in 77.8%, 66.7%, and 100% (p<0.01) of symptomatic patients respectively. Patients were followed for a mean period of 18 months (range 4-84 months). Median survival from the date of surgery (Kaplan-Meier, 95%Cl) was 11.6 (6.8 to 18.2) months, range 1 to 84 months. Cryosurgery provides a safe and effective method for the palliation of advanced central bronchial obstructive tumors, and compares favorably with other methods in terms of safety, cost, and complications. Initial experience suggests that similar palliation may be achieved by cryosurgery applied to advanced parenchymal tumor masses.

Adult↗
PubMed2001

Effects of cryoanalgesia on post-thoracotomy pain and on the structure of intercostal nerves: a human prospective randomized trial and a histological study.

OBJECTIVE: The choice of analgesia in the management of post-thoracotomy pain remains controversial. Although several alternative forms of post-thoracotomy analgesia exist, all have their disadvantages. Cryoanalgesia, localized freezing of intercostal nerves, has been reported to have variable effectiveness and an incidence of long-term cutaneous sensory changes. We carried out an animal study to assess the reversibility of histological changes induced by cryoanalgesia and a prospective randomized trial to compare the effectiveness of cryoanalgesia with conventional analgesia (parenteral opiates). METHODS: In six anaesthetized dogs, intercostal nerves were exposed to a varying duration of cryo-application (30, 60, 90 and 120 s). The nerves were biopsied and examined histologically at regular intervals over the following 6 months. In the clinical study, 200 consecutive patients undergoing thoracotomy were randomized to cryoanalgesia and conventional (parenteral opiates) analgesia groups. Postoperative pain scores, respiratory function tests and use of opiate analgesia were measured for the two groups. RESULTS: Following application of the cryoprobe, degeneration and fragmentation of the axons was evident with associated inflammatory changes. As the endoneurium remained intact, axonal regeneration took place after the resolution of axonal swelling. Over the course of weeks, recovery of the intercostal nerve occurred and was complete after 1 month for the 30 and 60 s groups. For nerves exposed to longer durations of cryoanalgesia, the time taken for complete recovery was proportionally increased. Clinically, there was a statistically significant (P<0.05) improvement in postoperative pain scores and use of opiate analgesia and an improvement (P>0.05) in respiratory function tests for patients in the cryoanalgesia group. The previously suggested cutaneous sensory changes resolved within 6 months with complete restoration of function. CONCLUSIONS: We suggest that cryoanalgesia be considered as a simple, inexpensive, long-term form of post-thoracotomy pain relief, which does not cause any long-term histological damage to intercostal nerves.

Adult↗
PubMed2001

Endobronchial cryosurgery.

The use of cryosurgery in the tracheobronchial region has been established for a considerable time, and it has been proved to provide a safe, rapid, and effective method for the restoration of patency in blocked tracheobronchial lumen. It also improves symptoms, respiratory function, and quality of life. The technique is easy to perform, economical, has minimal complications, and is well tolerated by the patient. Cryosurgery often leads to sufficient improvement in the patients' condition such that they can tolerate further treatments, such as radiotherapy or chemotherapy, thus providing a better outcome and improved quality of life and survival.

Bronchial Diseases↗
PubMed1999

The role of cryosurgery in palliation of tracheo-bronchial carcinoma.

OBJECTIVE: Carcinoma of the lung is the commonest cause of death from malignant disease in humans. At diagnosis, about 85% of patients are in an advanced stage of the disease and approximately 30% present with a tumour blocking a large bronchial lumen, causing distressing and life threatening symptoms. Early reopening and treatment of the blocked airways is required to improve symptoms and quality of life. There are a number of methods available to achieve this aim including cryotherapy, the controlled application of extreme cold. METHODS: We present a prospective study of 153 consecutive patients, cryotreated between January 1995 and December 1997 with a mean age of 68.8 years and a male:female ratio of 1.59:1. The procedure can be performed under general or local anaesthetic using a rigid or flexible cryoprobe. A temperature of about - 70 degrees C is delivered to the tumour site for two 3-min periods causing destruction of the tumour mass. Patients were evaluated clinically and for performance status before and after treatment. Histological composition was: non-small cell 88.2%, small cell 11.1% and malignant melanoma 0.7%. The TNM staging for NSC patients, at the time of treatment was stage II 8.2%, IIIa 27.4%, IIIb 25.9%, IV 38.5%. RESULTS: Subjective symptomatic improvement for cough was 68.3%, dyspnoea 63.9%, haemoptysis 92.7% and chest pain 55.5%. Respiratory function tests showed improvements in mean FEV1 from 1.34 l to 1.45 l (P = 0.001) and mean FVC from 1.93 to 2.02 l (P = 0.035). The Karnofsky performance status increased by 54.6%. Kaplan-Meier median survival time was 12.9 months. Complications were found with 11 patients (7.2%) and there was no operative mortality. CONCLUSIONS: Cryotherapy provides effective and rapid control of symptoms caused by tracheobronchial carcinoma and improves quality of life and survival. It is easy to perform, with minimum complications and the majority of patients are discharged the same day.

Adult↗
PubMed1997

The role of cryotherapy for airway complications after lung and heart-lung transplantation.

OBJECTIVE: Although airway problems after lung and heart-lung transplantation have been greatly reduced due to changes in surgical technique, excessive granulation tissue at the anastomosis may threaten airway patency. Treatment options include electrocautery, dilation, laser coagulation and stent placement however, recurrence remains a problem. Cryotherapy, the controlled application of extreme cold, is effective at causing cell lysis in granulation tissue and may therefore be effective after lung transplantation for airway problems arising from granulation stenosis. Our objective was to review our experience with cryotherapy as a first-line treatment for airways compromised by granulation tissue after lung and heart-lung transplantation. METHODS: A retrospective analysis of patient records after lung and heart-lung transplantation was performed. A total of 696 patients were identified who received lung or heart-lung transplants, 64 of whom were found to have granulation tissue at the site of airway anastomosis (8.9% of 721 airways at risk). When the granulation tissue was found to narrow the lumen by > or = 50% and affect lung function. RESULTS: The trachea was involved in 5 patients and the main stem bronchus in 16. Each patient required a mean of 2.6 +/- 2.0 cryoapplications. Anatomical results of cryotherapy were judged excellent to good in 15 patients and fair in 6 patients. Eight patients required endobronchial stenting as part of a multimodality treatment. Overall, the post-treatment FEV1 and FVC increased by 34 +/- 36% and 25 +/- 27% from pre-treatment values respectively (P < 0.001). In 13 patients in whom cryotherapy and dilation alone were effective, the FEV1 increased by 41 +/- 43% (range -11 +/- 138%) and the FVC by 28 +/- 29% (range -4 +/- 96%). These changes were also significant (P < 0.001). Changes in these two parameters were positively and significantly correlated (P < 0.01). Acturial survival at 3 and at 5 years were 57 and 43%, respectively (NS compared to total cohort), and median survival was 978 days (range 365-1862). Six patients are alive at a median follow-up of 5.75 years (range 0.6-8.3). CONCLUSIONS: We conclude that cryotherapy is a safe, effective treatment for excessive granulation tissue after lung and heart lung transplantation and may reduce the need for endobronchial stenting and limit recurrence.

Adult↗
PubMed1995

Cryotherapy for tracheobronchial disorders.

Cryotherapy is the therapeutic application of extreme cold for local destruction of living tissue. This technique has been shown to be effective and safe in treating endobronchial lesions, particularly in patients with endobronchial carcinoma and airway obstruction. This article describes cryotherapy and its use in treating tracheobronchial disorders.

Animals↗
PubMed1990

Bronchoscopic cryotherapy for advanced bronchial carcinoma.

A prospective study was carried out to assess the value of bronchoscopic cryotherapy for palliation of inoperable bronchial carcinoma with bronchial obstruction. Symptoms, lung function, and chest radiographic and bronchoscopic findings were recorded serially before and after 81 cryotherapy sessions in 33 consecutive patients. Most patients improved in terms of overall symptoms, stridor, and haemoptysis and they had an overall improvement in dyspnoea. Objective improvement in lung function was seen in 58% of patients and the changes in lung function correlated with symptoms. Bronchoscopic evidence of relief of bronchial obstruction was seen in 77% of patients and 24% showed improvement in degree of collapse on the radiograph. There were no important complications. These results compare favourably with the results in published series of patients having laser therapy. It is concluded that bronchoscopic cryotherapy is valuable for the palliation of inoperable bronchial carcinoma.

Aged↗
PubMed1986

Cryotherapy for advanced carcinoma of the trachea and bronchi.

Cryotherapy was used to relieve symptoms in 75 patients suffering from advanced carcinoma of the trachea or bronchi. In all patients surgical resection, radiotherapy, or chemotherapy had been tried and been unsuccessful or had been thought to be unsuitable because of the patients' poor general condition. In cryotherapy the intraluminal tumour was frozen through a Stortz bronchoscope. Localised necrosis increased the patency of the lumen of the trachea or bronchi, resulting in relief of symptoms. Cryotherapy is effective and easily performed and causes the patient little discomfort.

Adult↗
PubMed1986

Cryoanalgesia after thoracotomy. Improvement of technique and review of 600 cases.

The efficacy of cryoanalgesia for the control of post-thoracotomy pain has led to the acceptance of the technique as a routine procedure in this unit. A study of 600 consecutive patients in whom an improved technique was used is not reported. The freezing time for each intercostal nerve in this group was reduced to one 30 second exposure instead of the two 30 second exposures previously used. This reduced the duration of cutaneous numbness, with no loss of pain control. Freezing above the fifth intercostal nerve is no longer practiced in women. Modification to the probe has simplified the procedure. Pulmonary function studies and blood-gas analysis are also described.

Adolescent↗