Open Bronchial Stump Post-Pneumonectomy: Findings on Xenon-133 Ventilation Imaging

Open Bronchial Stump Post-Pneumonectomy: Findings on Xenon-133 Ventilation Imaging

Arnold F. Jacobson and Sharon A. Herzog

Nuclear Medicine Section, Department of Veterans Affairs Medical Center, Seattle, Washington

opment of a right hydropneumothorax (Fig. 1)which was deter A 67-yr-oldmale statuspost right pneumonectomyfor non mined at bronchoscopy to be due to failure of the right bronchial small cell lung cancer who later developed an open right stump closure. Because of the close proximity of the original bronchial stump underwent a ventilation-perfusion lung scan surgery to the carina, surgical intervention to close the open because of episodes of recurrent dyspnea suspected to be right bronchial stump was not attempted.Sincepulmonary em due to pulmonaryembolism.Xenon-i 33 ventilationimages bolism was considereda possiblecausefor the patient's current showed both rapid entry into and later washout of activity dyspneic episodes, ventilation-perfusion lung scintigraphy was from the air-filled portion of the right thoracic cavity. A wide performed. open bronchialstump, documented both at bronchoscopy On posterior ventilation imagingwith 133Xegas, xenon en and later autopsy, allowed the xenon gas to freely wash out tered into the upper half of the right thoracic cavity similar to the from the thoracic cavity, resulting in a different imaging pat left lung, which showed relatively normal first-breath and equi tern than for a typical bronchopleural fistula, which is usually librium ventilation (Fig. 2). On washout images, there was no characterized by prolonged trapping of radioactive gas within significant retention of the radioxenon in either the left lung or the pleural space. the upper right hemithorax. Perfusion imaging with 99mTc@/A@t@ J NucIMed 1993;34:462-464 (Fig. 3) showed absent uptake in the right chest consistent with previous surgical history and relatively normal perfusion to the left lung, essentially excluding the possibility of significant pul monary embolism. stimates of the frequency of failure of bronchial The patient had progressive deterioration in clinical symp toms and expired 2 wk following the lung scan. Autopsy recon stump closure following pneumonectomy range from 3% firmed patency of the right bronchial stump. to 12.5% (1—3).The severity of this failure can range from a small air leak which seals spontaneously with no se quelae to a wide open bronchial stump with fatal compli cations due to pulmonary insufficiency or sepsis (4). The characteristic finding on chest radiography in a patient @‘_- with a bronchial air leak is a lowering of the air-fluid level @w.- •- in the thoracic cavity (4). Ventilation scintigraphy with radioactive gas has been used to identify the presence of a bronchial leak, with the typical finding being entrance of gas into the thoracic cavity on single breath and equiib rium views, followed by prolonged retention during washout (5—8).We present an unusual case in which ventilation scintigraphy showed both free entrance and egress of gas from the thoracic cavity.

CASE REPORT A 67-yr-old male who had undergone a right pneumonectomy 8 moearlierfor non-smallcelllungcarcinomawasevaluated becauseof recurrent episodesof paroxysmal dyspnea.The pa tient's original postoperative course was complicated by devel

Received Sept 28, 1992; revision accepted Oct. 22, 1992. FIGURE 1. Chestx-raydemonstratesabsenceofrightlungin For correspondence or reprints contact Arnold F. Jacobson, MD, PhD, NudearMedicineSection,Dept.of VeteransAff@rsMed@&Center,1660S. patientstatus post-pneumonectomyand the rightthoracic cavity Columbian Way (115), Seattle. WA 98108. is partiallyfilled with fluid.

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FIGURE2. Posteriorequilibrium1@Xeventilationimage(A)showsaccumulationofradiotracerintheupperrightthoraciccavity. Washout imagesat I mm (B) and 4 mm (C) show relativelynormal clearanceof xenon from both the native left lung and the right thoracic cavity.

DISCUSSION leaks (5—13).In the postpneumonectomy patient, this di Following a pneumonectomy, the thoracic cavity fills agnosis is usually less in doubt than in patients with with fluid, with total opacification usually occurring over empyema, localized lung resection, or pneumothoraces, a period of 3 wk to 7 mo (4). If the bronchial stump in that typical changes in the chest radiograph usually develops an air leak, the amount of fluid in the thoracic suggest the diagnosis. In our patient, the patent bronchial cavity typically decreases either due to increased absorp stump had been identified on prior bronchoscopy, and the tion by the parietal pleura or loss through the patent lung scan was performed for suspicion of pulmonary em bronchus. This results in a reduction in the height of the bolism, a case similar to that described by Roswig (7). fluid level in the postpneumonectomy space commonly Although prior reports have demonstrated various observed on chest x-ray. Infection of the postpneu amounts of radioactive gas or radiolabeled aerosol enter monectomy fluid and respiratory insufficiency are impor ing into the affected lung or thoracic cavity on inhalation tant causes of morbidity and mortality in patients with imaging, our case employs radioactive gas to show rapid failure of bronchial stump closure (2—4). washout of activity from the thoracic space comparable A numberof previous reports havedescribedthe utility to that observed in the native lung. It is understandable of radionuclide ventilation imaging in the diagnosis and why trapping occurs in a patient with a communication localizationof bronchopleuralfistulaeand bronchialair between a bronchus and the visceral pleura, with both parietal and visceral pleura present, in that there is no ready mechanism for clearance of this gas once it has diffused throughout the available pleural space. In con trast, with an open bronchial stump postpneumonec tomy, the communication is between the bronchus and the parietal pleura, or more specifically the thoracic cay ity, and, assuming there is sufficient air exchange in the cavity, clearance of the radioactive gas on washout im aging should occur without significant impediment. Pos sible explanations for previously observed trapping of radioactive gas in patients with postpneumonectomy bronchial fistulae include the presence of only a relatively small opening which behaved similar to a ball valve, allowing free entrance but minimal exit of radioactive gas, or paralysis of the hemidiaphragm on the side in question, with tracer diffusing into the thoracic cavity but FiGURE 3. Posterior @°@“Tcclearing only slowly in the absence of significant inspira MAAlungperfusionimagedem tory or expiratory forces. The quantity of ‘33Xeentering onstrates absence of activity in the rightchest,whichis consis into the thoracic cavity in our patient appears signifi tentwith priorpneumonectomy. cantly greater than that shown in images from several

Xenon-i33 Imaging of Open Bronchial Stump •Jacobson and Herzog 463 previous case reports (5—7),suggestingthat there was a 3. Horei-Madsen M, Schulze S, Pederson VM, Halkiei E. Management of larger communication between the bronchus and thoracic bronchopleural fistula following pneumonectomy. Scam! I Thorac Car diovasc Sui@ 1984;18:263-266. cavity in our patient than in those previously described. 4. ShieldsTW. Pulmonaryresections. In: ShieldsTW, ed. Generalthoracic The lung scan in our patient showed the features de swgeiy, 3rd edition. Philadelphia: Lea & Febiger; 1989:361—377. scribed as a “pseudoventilation-perfusion mismatch― (7) 5. ZelefskyMN, FreemanLM, SternH. A simpleapproachtothediagnosis of bronchopleuralfistula.Radio1o@1977;124:843—844. with the additional feature of normal washout from the 6. Lowe RE, SiddiquiAR. Scintimagingof bronchopleuralfistula:a simple thoracic cavity that was not seen in the previous report. method of diagnosis. Clin Nuci Med 1984;9:10—12. Observation of the scan pattern seen in the present case 7. Roswig DM, Szildas ii, Rosenberg RJ, Spencer RP. Bronchopleural should alert the interpreting physician of the likelihood of fistulademonstratedby pulmonaryscintigraphy—a“pseudo―ventilation perfusion mismatch. Clin Nuci Med 1984;9:240. a large leak, suggesting complete failure of bronchial 8. Dixon C, Ali MK, Atallah MR. Ewer MS. Postresection bronchopleural stump closure. fistula:detection by regionalventilation-perfusionstudies. South Med I 1983;76:485—486. 9. VinckenW, SchandevylW, Sonstabo R, BossuytA. Demonstrationof a ACKNOWLEDGMENT bronchopleural communication by inhalation of Kr-81m gas. Clin Nuci Med 1981;6:117—119. This work was supported by the Veterans Health Services 10. Uilington GA, Stevens RP, DeNardo GL. Bronchoscopic location of and Research Administration of the Department of Veterans bronchopleural fistula with xenon-133. I Nuci Med 1982;23:322—323. Affairs. 11. Skorodin MS. Gergans GA, Zvetina JR. Siever JR. Xenon-133 evidence of bronchopleural fistula healing during treatment of mixed aspergillus and tuberculous empyema. I Nuci Med 1982;23:688—689. REFERENCES 12. Moote D, Ehrlich L, Martin RH. Postpneumonectomy bronchopleural fistulaimagedby ventilation lungscanning. CliiiNuci Med 1987;12:337— 1. Pomerantz AH, Derasari MD, Sethi 55, Khan S. Early post-pneumone 338. ctomy bronchial stump fistula. Chest 1988;93:654—657. 13. Hollett P, Wright E, Wesolowsky C, Hams R. Aerosol ventilation scm 2. Beltrami V. Surgical transsternal treatment of bronchopleural fistula post tigraphy in the evaluation of bronchopleural fistula: a case report and pneumonectomy. Chest 1989;95:379—382. literature review. Can I Surg 1991;34:465—467.

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