Calvin S.H. Ng; Anthony P.C. Yim 

Curr Opin Pulm Med.  2006;12(4):273-277.  ?2006 Lippincott Williams & Wilkins

Abstract and Introduction

Abstract

Purpose of Review: Spontaneous hemopneumothorax can be life threatening, and is a cause of patients presenting with unexplained signs of significant hypovolemia. The debate relating to patient selection and timing of surgery in patients with spontaneous hemopneumothorax remains unresolved.
Recent Findings: Our experience together with the latest series published over the last decade on the conservative and surgical management of spontaneous hemopneumothorax are presented and discussed.
Summary: Surgery should be performed early in the management of spontaneous hemopneumothorax to reduce morbidity. In particular, video-assisted thoracic surgery, which is associated with potentially fewer post-operative complications and shorter hospital stays compared with thoracotomy, should be considered in patients with spontaneous hemopneumothorax who are hemodynamically stable.

Introduction

Läennec in 1828 was credited with the first description of spontaneous hemopneumothorax (SHP), which was diagnosed post mortem. Subsequently, the successful treatment of SHP by thoracentesis was performed by Whitaker in 1876.^[1] Since then, SHP has become a well documented clinical condition that is associated with 1-12% of all spontaneous pneumothoraces.^[2,3] The patients can often deteriorate very quickly due to hemodynamic instability as a result of continued blood loss. In addition to fluid resuscitation and blood transfusion, surgical intervention is often required in the management of SHP. Tube thoracostomy, aspiration of the hemothorax, thoracotomy, and decortication after the initial period of rest have all been used to treat SHP. More recently, video-assisted thoracic surgery (VATS) has been used successfully in the management of spontaneous pneumothorax, with the added advantages of less tissue trauma and reduced post-operative pain when compared with traditional thoracotomy approach.^[4,5] Furthermore, VATS is increasingly being used for the management of SHP, with favorable results in terms of reduced hospital stay and morbidity.^[3,6]

Presentation and Etiology

The development of spontaneous hemothorax can result from thoracic malignancies, primary vascular events, coagulopathy, spontaneous pneumothorax and a variety of infectious diseases. SHP is an uncommon but potentially life-threatening clinical situation due to rapid ventilatory collapse and the large volume of concealed blood loss into the pleural cavity. It is one of the causes of patients presenting with unexplained signs of significant hypovolemia.

Between 80 and 100% of patients with SHP present with their first episode of pneumothorax, while 10-12% represent pneumothorax recurrences, and 10% have had a previous contralateral pneumothorax.^[2,3,6,7] Chest roentgenogram remains the most useful investigation in the diagnosis of the condition^[3,7] (Fig. 1). In a large series of SHP patients, 70% of chest radiographs demonstrated hydropneumothorax, while the remainder showed some opacity and obscurity of the costophrenic angle.^[7] It should be emphasized, however, that the admission chest roentgenogram may show only pneumothorax in 10% of SHP patients, with radiological evidence of hemothorax developing later.^[3] There has been some argument that tube thoracostomy insertion may have been the cause of such cases of hemothorax; however, bleeding from vascular adhesions can be usually confirmed later intra-operatively. Failure of the initial chest roentgenogram to show hemothorax can be due to the film being taken too early, a supine rather than an erect/sitting chest film, or the possibility of delayed hemorrhage from the vascular adhesion band. Hwong et al.^[3] reported two patients in their series who had no initial drainage from tube thoracostomy. The first patient had delayed bleeding from the torn vascular adhesion, as recorded by the delayed high-drain output. In the other patient, the position of the tube thoracostomy was relatively apical, causing a slight delay in the 'initial' drainage of hemothorax. The presence of significant dyspnea and lower levels of blood hemoglobin are indicators of SHP rather than spontaneous pneumothorax.^[8*] Measuring the hemoglobin level of the pleural fluid may also be a useful tool to help differentiate between SHP and blood-stained effusion. Computed tomography can be considered in cases where the diagnosis of SHP is in doubt,^[9] or to exclude neoplasia in hemodynamically stable patients prior to elective surgery. Past experience has shown that 13-46% of patients with SHP will develop hypovolemic shock (systolic blood pressure ≤90 mmHg),^{[2,3,6,7,10**]} and blood transfusion may be necessary in 64-100% of these patients.^[3,6]

Figure 1. 

Representative chest roentgenogram of spontaneous hemopneumothorax before surgical intervention

     

The source of the bleeding can be a small non-contractile vessel in an area of torn vascular adhesion between the two layers of the pleurae^[2,3,6,10**] (Fig. 2), rupture of a vascular bulla or lung parenchyma at the apex of the lungs^[2,6,7,10**] (Fig. 3), or the presence of an aberrant vessel that is usually thin-walled and does not contract adequately due to the lack of muscular fibres.^{[2,3,6,7,10**,11]} Interestingly, more recent pathological studies have shown vessel degeneration and sclerosis, as well as intima-media fibrosis, to be the likely causes of vasoconstriction failure in these aberrant vessels.^[2] The bleeding adhesions in SHP are commonly found near the apex and subclavian vessels, and also in the aorta, superior vena cava and pericardium. Normal hemostasis by vasoconstriction and clot formation may be impeded by lung movement, changes in pleural pressure during respiration and the absence of a surrounding tamponade effect. In our experience, the source of bleeding can be identified intra-operatively in 53% of SHP patients; bleeding occurs most commonly from a torn vascular adhesion band from the apical parietal pleura, which accounts for three-quarter of cases. In comparison, authors of other series were able to identify a source of bleeding in 50-100% of their cases,^[2,6,7,10**] and around half of the identified bleeding was from an aberrant vessel.^[6,10**]

Figure 2. 

Multiple bullae with highly vascular wall at the apex of left upper lobe

     

     

Males are between 8 and 30 times more likely to develop SHP than females.^{[2,3,7,10**,12]} The reason for the relative infrequency of SHP in females is not clear but is well documented, and only a handful of cases have been reported in the English literature.^{[6,10**,12,13]} Fry et al.^[12] suggested that there is an increased bleeding tendency in males due to their additional strength and vigor, but this theory fails to explain why SHP occurs while the patients are at rest. SHP has also been reported to be associated with other conditions, such as congenital cystic adenomatoid malformation,^[14] Ehlers-Danlos syndrome,^[15] sarcoidosis,^[16] systemic lupus erythematosis^[17] and cystic lung metastasis.^[18] Rarely, SHP may be the presenting feature of hemophilia.^[19]

Management of Spontaneous Hemopneumothorax: Conservative Versus Surgical

Mortality from SHP remained relatively high until the open surgical management of SHP became a realistic option in the late 1940s onwards.^[20,21] The debate relating to patient selection and timing of surgery in SHP patients remains unresolved. The initial management of SHP patients should be tube thoracostomy and resuscitation. Several centres have advocated a conservative approach with tube thoracostomy, as for uncomplicated pneumothorax, which they report can be successfully adopted in most cases of SHP. In contrast, others advocate such conservative management only in a select group of patients where bleeding subsides within 24 h and the patients remain hemodynamically stable.^{[7,10**,22,23]} It should be borne in mind that the presence of a blocked or poorly positioned chest drain can result in underestimation of the severity of the situation; in addition, many SHP patients are young, and will tolerate significant hypovolemia before developing hemodynamic decompensation. Furthermore, in one series where patients were managed conservatively, many were discharged with residual hemothorax, although only a minority of them later developed empyema or trapped lung (fibrothorax).^[22]

Our experience has shown that all SHP patients will benefit from surgical intervention as an emergency or non-emergency procedure during their hospital stay if optimum results are to be achieved. Emergency surgery is indicated if the patient has hemodynamic instability or there is continuously high output from tube thoracostomy.^[3,10**] The need for non-emergency surgery for SHP arises when complications relating to the SHP occur, or if there is persistent air leak with pneumothorax^[2,3,7] ( Table 1 ). Furthermore, a potential pitfall of conservative management is the need to delay decortications due to re-accumulation of fluid in the pleural cavity and lung restriction.^[2,3] Several series showed that between 14 and 75% of SHP patients who were treated conservatively subsequently required decortication surgery.^[2,7] Another consideration in favor of surgery is the young age of SHP patients, which places them in the low-risk category for anesthetic. In addition, the benefits of performing surgery while patients are stable before the onset of decompensated hemodynamics should not be underestimated. Several series have also noted that patients who were initially managed conservatively but subsequently required surgery, therefore resulting in a prolonged hospital stay, reported a poor quality of life.^[2,7]

Once the decision has been made to undergo surgery, the patient should be optimized with adequate fluid resuscitation and transfusion if necessary. SHP patients who require blood transfusion typically have drainage of more than 1200 ml, and represent between 10 and 20% of cases.^[2,3,7] Patients with underlying conditions, such as clotting abnormalities in hemophiliacs, should be treated appropriately prior to surgery.^[19] Recently, autologous blood transfusion from blood salvaged from the pleural space by cell-saving device systems has been used successfully in SHP patients undergoing emergent surgery, thereby avoiding the risks associated with allogeneic transfusion.^[24]

Management of Spontaneous Hemopneumothorax: Video-assisted Thoracic Surgery Versus Open Surgery

The advent of VATS has caused a paradigm shift in the way many thoracic conditions are managed, and this technique is now considered the gold standard in the treatment of spontaneous pneumothorax.^[4,5] When compared with the conventional thoracotomy operation, VATS for spontaneous pneumothorax and major lung resection is known to have quicker access time, less access trauma, reduced post-operative pain, attenuated post-operative immunosuppression, and faster recovery with shorter post-operative hospital stay.^[4,5,25,26]

In the context of SHP, early surgery in the form of VATS can help to reduce the incidence of delayed surgical exploration and decortication. In particular, VATS offers the added advantages of a better view of the pleural cavity, and more precise identification of bleeding via the magnified lens and hence direct hemostasis. Furthermore, evacuation of clotted blood from pleural cavity, sealing the area of air leak with endoscopic stapler and mechanical pleurodesis, as well as placement of the drainage tube under direct thoracoscopic vision, can all be performed by VATS with minimal access trauma.^[3,4,5,10**] In addition, the smaller wounds of VATS^[27] can lead to significantly less blood loss, which is particularly important in SHP patients who may already be coagulopathic.^[19] The results from our experience and that of others support the practice of VATS in the management of SHP, with potential advantages of shorter post-operative stay and fewer complications for the patient compared with open surgery^[3,6] ( Table 2 ). Thus, VATS is increasingly considered as a better alternative to the open approach for SHP.^[3,6] Even among advocates of access by open thoracotomy, many surgeons are now recommending early surgery to reduce hospital stay and improved cost-effectiveness.^[2,7] Nevertheless, VATS is generally contra-indicated in SHP patients with hemodynamic instability unless there is prompt and complete response to fluid replacement therapy.^[2,3,10**] In cases of shock or where major bleeding is encountered, thoracotomy remains the access of choice. Some centers also recommend thoracotomy for more chronic cases where adhesions may be present; however, we have not encountered major difficulties performing adhesiolysis with VATS.^[28]

Conclusion

In conclusion, SHP is potentially a life-threatening condition, and should be considered as a cause in patients presenting with unexplained signs of significant hypovolemia, particularly in young male patients. Early surgery may help reduce the incidence of delayed surgical exploration and decortication. Furthermore, in experienced centers, surgery for SHP in the form of VATS should be considered for patients who are hemodynamically stable. Larger prospective trials are warranted in order to better define the algorithms and role of surgery in the management of SHP.