Pneumonectomy

Approximately 1 to 4 percent of all patients with lung l cancer will demonstrate multiple primary lesions (ei­ther synchronously or metachronously). Those whose ini­tial lung carcinoma was cured by resectional surgery have an approximately 5 to 10 percent chance of developing a second or even a third primary tumor. In addition, carcinoma of the lung may occur in patients with a previous lung resection for nonmalignant disease. The decision to proceed with surgical resection in such patients is an extremely difficult one; without surgery, they will succumb to their malignancy, while with surgery they are at high risk of dying from respiratory failure and/or pulmonary hyper­tension. Several preoperative tests have been suggested to predict the functional integrity of the lung after resection. Among these, quantitative perfusion lung scanning coupled with spirometry has been shown to accurately predict postoperative pulmonary function, and balloon occlusion of the pulmonary artery supplying the lung to be resected has been used successfully to quantitate the expected postoperative pulmonary pressures in patients considered for pneumonectomy. We present a patient with a previous left pneumonectomy in whom these techniques were adapted for the lobar level preoperatively before completing a right upper lobectomy.

Case Report

A 59-year-old asymptomatic man, who had undergone a left pneumonectomy 20 years previously for squamous cell broncho­genic carcinoma, was found to have a new 5-cm right upper lobe mass on an annual chest radiograph. Results of fiberoptic bronchos­copy showed an unremarkable left mainstem stump and no endo­bronchial lesions; transbronchial biopsy of the nodule revealed squamous cell carcinoma. The patient had a 100 pack-year smoking history, as well as significant asbestos exposure 40 years previously. Physical examination revealed a healthy appearing white man with absent breath sounds over the left chest and a well healed left thoracotomy scar. Neurologic examination was normal. No lymph- adenopathy or hepatosplenomegaly was present. Computed tomog­raphy of the head and abdomen revealed no metastases; bone scan showed no abnormal uptake. Preoperative pulmonary function studies showed moderate restrictive changes (Table 1).  levitra plus

Table 1—Pulmonary Function Testing Results

Preoperative

Postoperative

Observed

% Predicted*

2 Months

23 Months

FVC(L)

2.63

60

1.16

1.85

FEV, (L)

2.38

69

1.09

1.49

FEV./FVC (%)

90

93

80

TLC(L)

4.09

60

2.56

3.35

MW (L-min’)

67

47

44

55

Deo (mbmin1

20.7

71

8.9

21.6

mm Hg1)

Dco/VA

6.0

4.3

8.0

pH

7.45

7.39

7.42

PaC02 (mm Hg)

44

38

42

Pa02 (mm Hg)

90

71

75

Sa02 (%)

96

94

95

A quantitative perfusion lung scan showed 44 percent of total blood flow to the right upper zone and 56 percent to the right middle and lower zones. By assuming that the topographic zones corresponded to lobes and by multiplying the relative blood flow to the middle and lower lobes by the preoperative lung function, a postoperative value for the one second expiratory volume (FEVJ of 1.33 liters was predicted for an uncomplicated right upper lobec­tomy. To better evaluate the patient from a functional point of view, right heart catheterization with balloon occlusion of the right upper lobe pulmonary artery branch was performed (Table 2).

Table 2—Right Heart Catheterization

Before

After

Occlusion

Occlusion

PA-systolic (mm Hg)

28

31

PA-diastolic (mm Hg)

7

8

PA-mean (mm Hg)

18

18

Cardiac output (L-min’1)

12.5

11.7

Cardiac index (L-min ~ um -»)

5.87

5.52

After mediastinoscopy revealed no hilar tumor, right thoracotomy confirmed a localized right upper lobe tumor mass. Cross-clamping of the right upper lobe pulmonary artery showed no significant rise in pulmonary arterial pressure; therefore, right upper lobectomy was carried out. Immediately postoperation, pulmonary arterial pressure was 43/15 mm Hg with a pulmonary capillary wedge pressure of 4 mm Hg. The patient was extubated on the second postoperative day. Arterial blood gas analysis on 4 L/min Os showed pH = 7.33, PaC02=46 mm Hg, and РаОг=112 mm Hg. Right lower lobe pneumonia (fever, leukocytosis, and lung infiltrate) responded to intravenous gentamicin and piperacillin. He was discharged two weeks postsurgery. Considerable dyspnea occurred with minimal exercise but was attenuated by increasing oxygen from 2 L/min at rest to 4 L/min with exercise.

Pulmonary function studies performed two months after dis­charge from the hospital showed severe restrictive changes as predicted (Table 1). Treadmill exercise testing with the patient breathing room air showed Sa02 of 82 percent with a pulse rate of 96/min after 5 min exercise at 0.5 mph, 0 grade; the desaturation was attenuated by 2 L/min supplemental Oa. Twenty-three monthsafter resection, the patients lifestyle was unencumbered, and supplemental Os (1 L/min) was used only during sleep. Results of pulmonary (unction studies showed improvement (Table 1). Unfortunately, a 4-mm squamous cell carcinoma with features of carcinoma in situ was discovered during fiberoptic bronchoscopy at the right upper lobe stump site, and the patient is presently undergoing a combination of external beam radiation therapy and endobronchial brachytherapy.
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