ISKANDER AL GITHMI, M.D. L UNG V OLUME R EDUCTION S URGERY ( L V R S )

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Transcript of ISKANDER AL GITHMI, M.D. L UNG V OLUME R EDUCTION S URGERY ( L V R S )

ISKANDER AL GITHMI, M.D.

LUNG VOLUME

REDUCTION SURGERY

(L V R S)

BACKGROUND

Dr. Brantigan in 1957 was the first person to present the concept of LVRS.

His concept, based on “Under normal circumstances, the elasticity of expanded lung is transmitted to the small

airways which held opened bycircumferential elastic pull”

In emphysema this elasticity and circumferential pull on the small airways

are lost.

He proposed “Resection of the most useless area and

Down sizing the lung would help to restore the outward pull

on the small airway”

In 1991, Wakabayashi and colleague reported using the carbon dioxide laser to shrink

bullous areas of the lung via VATs.

In 1995, Cooper and Associate a modification of Brantigan’s volume reduction operation,

in which lung tissue was resected from both lungs via median sternotomy.

He reported his initial 20 cases with no operative mortality and the operation produced an 82% mean

increase in FEV1.0 and significant improvement in 6 min. walking distance.

In 2001, Cooper and associate report 6 cases of endobronchial bypass procedure

by creating extra-anatomic broncho-pulmonary passage and placing a stent.

His concern? How long the stent stay open.

OVERVIEW

EMPHYSEMA:

is a condition of the lungcharacterized by abnormal permanent

enlargement of airspace distal to the terminal bronchiole, accompanied

by destruction of their wall in the absence of fibrosis.

PATHO PHYSIOLOGY

Loss of elastic recol

Expansion of rib cageand flattening the

diaphragm

Increase resting volume

Inefficient respiratory muscle

Increasework of breathing

Dyspnea

PATIENT SELECTION

NOT ALL PATIENTS BENEFIT FROM LVRS

Severe emphysema not reversible by medical treatment.

Poor exercise performance.

Marked hyperinflation.

Indication :

EXCLUSION CRITERIA

Advanced age, above 70 years

Paco2 more than 55 mmHg.

Mean pulmonary artery pressure >35mmHg

Psychosocial unstable

Severe active infection: bronchiectasis, TB

Malignancy with life expectancy less than 2 years

Significant coronary artery disease not candidate for revascularization.

INCLUSION CRITERIA

Age less than 75 years

FEV1.0 less than 35% of predicted value

TLC more than 125% of predicted value

RV/TLC more than 0.6

Vo2 max. less than 12 ml/kg/min

Highly motivated and stably psychosocial patient.

Radiological evidence of heterogenous distribution of emphysema.

PATIENT EVALUATION

Initial screening: routine CXR PA and lateral.

Standard pulmonary function tests.

Extensive history and exam.

On this basis 70% of applicants are turned

down, due to a lack of distension or the

presence of homogenous severe

destruction throughout the lung.

FINAL EVALUATION

HRCT scan

Quantitative V/Q scan

Lung-volume measurement

Dobutamine echo cardiogram

6-minute walk test (140 m)

OUTCOME MEASURE

PRIMARY MEASURES

According to NETT study group

- Survival

- Maximum exercise capacity

SURVIVAL is chosen as primary measure because…

- It is clinically significant

- It can be assessed early and quantified

OUTCOME MEASURE

MAXIMUM EXERCISE IS CHOSEN BECAUSE

- It is easier to standardize

- More reproducable than 6 min walk test

- There is no study document a consistent

relationship between improvement in functional status and changes in pulmonary function.

SECONDARY MEASURES

Quality of life and specific symptoms: dyspnea

Pulmonary function and gas exchange

Radiologic studies… - CT scan to verify the presence of emphysema and to assess the severity of the disease.

6 Minute Walking Test: - to assess the exercise performance

Source: JTCS 1999, 118

Does lung functions improve after LVRS?

Source: JTCS 2002: 123:845

Konrad et al have reported 115 patients underwent LVRS.

Symptoms and lung functions were assessedbefore the operation and 3, 6 and every 6 months after the operation.

CONCLUDE FEV1.0 peaks within 6 months postoperative then decline in the fist year and slows down in succeeding years to baseline.

RELATION BETWEEN AGE AND CLINICAL OUTCOME

RELATION BETWEEN RADIOLOGICAL PATTERN AND CLINICAL OUTCOME

SURGICAL INTERVENTION

LVRS performed by means of bilateral VATSor median sternotomy (buttressed or nonbuttressed with bovine peri cardium).

Resection is directed to the target areas identified by means of analysis of the CT scan and perfusion scan as the lung and the lung zones with the most pronounced emphysematous alteration and greatest reduction in perfusion.

PATIENTS AT HIGH RISK OF DEATH AFTER LVRS

A total of 1033 patients had been randomized by June 2001.

69 Patients had FEVI < 20% of their predicted value and homogenous distribution of emphysema on CT scan or their DLCO < 20% of predicted value.

The 30-days mortality rate after surgery was 16% as compared with the rate of 0% among 70 medically treated patients (P < 0.001).

Concluded: Very low DLCO Very low FEV1.0

Homogenous distribution of emphysema are at high risk of death after LVRS. Source: NEJM 345: 1075 – 1083 Oct. 2001

ISSUES AFTER L V R S

DEVELOPMENT OF PULMONARY HYPERTENSION

Weg. et al reported that development of pulmonary hypertension may occur afterLVRS.

9 Patients were involved in a prospectivestudy with an average age of 64 yearsAfter LVRS (PA) systolic pressure rose to 47.69 ± 12.4 mmHg but the changes in PAP did not correlate with the changes insymptoms.

Source: AM.J. Respir. Crit Care, 1999

TAKE HOME MESSAGE

There are no long term data as yet.

LVRS improved the life of many patients.

We are still on a learning curve in predicting outcome after LVRS.