by Harwood Academic Publishers Printed in Singapore lnterventional Pneumology in Pulmonary Bleeding A Review: From the Bronchus to the Vessel

Interventional pneumology includes both bronchological and vascular methods of diagnosis and therapy, especially in emergency situations such as pulmonary hemorrhage. In massive pulmonary hemorrhage bronchological diagnosis is required to determine the site and extent of bleeding, as well as angiography of bronchial arteries, and of pulmonary arteries. Bronchus occlusion by aid of balloon catheter or double lumen tube are holding measures until definitive surgery or embolization of bronchial or pulmonary arteries can be performed. The paper suggests a close relationship between bronchoscopic and angiographic diagnosis and therapy in case of severe pulmonary bleeding.


INTRODUCTION
The etiological spectrum of hemoptysis has been changing over the last few decades. Tuberculosis was the most frequent cause of pulmonary hemorrhage 40 years ago. Today inflammatory and neoplastic diseases have taken over this position, because of the decrease of tuberculosis. The incidence of pulmonary hemorrhage in the case of vascular abnormality (e.g. arteriovenous fistulae, collateral pulmonary and bronchial arteries in patients with cyanotic heart disease) and cardiac diseases is about 9% (Johnston and Reisz, 1989). Pulmonary bleeding is classified in a three-step score (I < 20 ml/d, II 20-200 ml/d, III > 200 ml/d).
In tuberculosis and bronchiectasis approximately 40% of all pulmonary bleeding episodes are massive (degree III). In bronchitis and bronchial carcinoma massive bleeding (III) is found in 13%, or 5 to 7% respectively (Conlan et al., 1983).
Hemoptysis with loss of blood > 600ml is associated with a mortality of up to 50% (Corey and Hla, 1987).
The sources of bleeding are often bronchial or intercostal arteries, and rarely pulmonary arteries. 20 C. WITT et al.

FIGURE
Most common origins of bronchial arteries, based on angiographic findings in 72 patients (a: 31%, b: 25%, c: 13%, d: 12%). Reprinted from Uflacker. Bronchial arteries accompany the bronchi to the level of the respiratory bronchioles, where they anastomose with pulmonary vessels. The origins of bronchial arteries show wide variation, which can, in 80% of the cases, be described by four patterns (Fig. 1). In 40% two bronchial arteries come from the left side and one intercosto-bronchial trunc from the fight side of the aorta at the fifth or sixth dorsal vertebra (Ds, D6). In general, many of the right bronchial arteries originate together with intercostal arteries (intercosto-bronchial trunc) from the posterio-lateral side of the aorta, while left bronchial arteries are more likely to originate directly from the anterior aortic wall.

DIAGNOSIS OF PULMONARY HEMORRHAGE
Diagnosis of pulmonary hemorrhage always starts with taking a history (quantity, colour, aspect, duration and time of the bleeding). This includes information about possible underlying diseases (inflammation, tumor, cardio-pulmonary malformations, bronchiectases, heart failure, rheumatologic diseases like Wegener's disease, Goodpasture syndrome, and acute lupus pneumonitis) and coagulation problems. Subsequent clinical examination comprises blood pressure, ventilation, blood gases, and the current status, e.g. colour of the expectorated blood.
Localized lung processes (infiltrations, circular foci, caverns) can be found in only half of patients on chest X-ray (Poe et al., 1988). High resolution computed tomography (HRCT) is helpful to detect small lesions in 50% of the patients with normal chest X-ray (McGuinness et al., 1994;Naidich et al., 1990). This is valid for peripheral diseases and parenchymatous lesions which are not accessible by means of diagnostic bronchoscopy (Jackson et al., 1985). In any case imaging is useful to show the extent of the bleeding and resulting condition of parenchyma and airways.

BRONCHOSCOPY AND ANGIOGRAPHY IN PULMONARY HEMORRHAGE
Diagnostic bronchoscopy provides information about localization (segment or lobe), activity, and endobronchial causes of the bleeding (Lederle et al., 1989). In smokers over 40 years (> 40 pack-years) suffering from hemoptysis for more than one week, a lung tumor is most likely to be the cause of bleeding and therefore has to be excluded (O'Neil and Lazarus, 1991). In case of massive pulmonary hemorrhage it can be extremely difficult to determine the site of bleeding, because blood can be found in every part of INTERVENTIONAL PNEUMOLOGY IN PULMONARY BLEEDING 21 the lung. Under such circumstances bronchoscopy reveals the source of bleeding in only 43% (Knott-Craig et al., 1993). Even if X-ray or CT scan show a suspect lesion the findings should be confirmed by bronchoscopy, because a radiographically visible lesion might not be the actual source of bleeding (Figs. 2a and 2b) (Witt et al., 1995). Thoracic computed tomography and bronchoscopy are essential diagnostic procedures in pulmonary hemorrhage.
If the patient arrives with active bleeding, his clinical condition determines the course of management. In case of severe hemorrhage emergency bronchoscopy and, if necessary, bronchus occlusion are indicated. If the situation is less urgent thoracic X-ray and computed tomography should be performed prior to endoscopic intervention (Mfiller, 1994;Set et al., 1993). If the bleeding continues bronchial-, intercostal-, or pulmonary arteriography has to be added. Origins and anatomy of bronchial arteries can be detected in retrograde aortography. Whenever a vessel is suspected to be the source of bleeding, it has to be visualized selectively. In arteriography the most important direct sign of bleeding is the extra-vasation of contrast agent (Fig. 3a). Indirect signs are hypervascularisation, atypical vessel convolutions and aneurysms (Fig. 3b) (Rabkin et al., 1987;Stoll and Bettman, 1988). If a suspect vessel cannot be found at its usual anatomical place, all other known abberant origins of bronchial arteries should be checked (Newton and Preger, 1965   Even spontaneous resolution of the bleeding can be observed with bed rest. In massive active bleeding hemostasis has to be performed as fast as possible according to a differential therapeutic strategy. Surgical intervention is indicated if the patient is operable. Mortality after lung resection in case of bleeding tuberculosis (7.1%) is even lower than mortality after drug and interventional therapy (11.5%), and surgery is superior with regard to recurrence (Knott-Craig et al., 1993).
If the patient is inoperable due to general or local reasons bronchological intervention is indicated. In rare cases the source of bleeding is visible to the endoscopist (e.g. intraluminal carcinoma). This makes topical application of vasopressor drugs and subsequent Nd YAG-laser coagulation possible (Figs. 4a and 4b). More often the origin of bleeding will not be visible so that ballon occlusion of lobe bronchus or even main bronchus is inevitable (Fig. 5). This temporary measure should stabilize the patient's vital functions for any subsequent surgical or vascular intervention. A simple but effective tool for this purpose is the CARLENS(R)-tube which ensures ventilation in the contralateral bronchial system.
One of the most efficient interventions for interruption of pulmonary bleedings is artery embolization of bronchial (BAE), intercostal, or pulmonary arteries (Wholey et al., 1976) (Figs. 6 and 7). Micro-metallic coils with or without FIGURE 3a Contrast agent extravasation in recurrent bleeding (secondary findings: metal coils from previous embolization).  dacron fibres and gelatin sponge are most commonly used for vessel occlusions. In case of hypervascularisation the use of metallic coils should be combined with Microspheres (150 to 500 micron) or liquid occlusive agent (Ethiblock(R)). Mechanisms of action are mechanical occlusion, platelet aggregation or gel precipitation. Severe complications after BAE are occlusions of accessory spinal vessels with subsequent ischemia of the spinal cord (Vujic et al., 1980). This may be the case in fight intercostal arteries (Ds) or in a common fight intercosto-bronchial trunc (DiChiro, 1974).
Complications are encountered in 0.7% of the procedures (Lamarque and Senac, 1979). Remy et al. (1977) presented successful hemostasis in 84% of the patients treated in 1977. Similar resuits have been achieved by other groups dealing with inflammatory diseases (tuberculosis, bronchiectases, abscess, aspergilloma).  Arrest of bleeding due to Nd-YAG-laser radiation in case of visible source of bleeding.  observation showed reccurence of bleeding in 10 of collaterals, and neovascularisations in active to 44% (Cremaschi et al., 1993). tumors. In every case re-embolization can be In patients suffering from bronchial carci-performed (Katoh et al., 1990 noma, but recurrence rate was 32% in one surgical (lung resection)interventions are indimonth follow-up (Witt et al., 1995). These results cated. The high mortality associated with lung can be explained in light of the state of the resection (4-5%) (Gomes et al., 1989) dictates underlying malignancy. Tumor-specific therapy that embolizaton should be the method of can support the results of BAE and help to reduce choice, at least in the case of multiple arteriobleeding recurrence. Some patients can be transvenous fistulae. In these cases detachable balferred to surgery after embolization (Uflacker loons (Figs. 8a and 8b) or micro-metal coils with et al., 1985). In case of recurrence, bronchial or without dacron fibres have been employed arteriography has to be performed to detect successfully (Solomon et al., 1991;White et