5 курс / Пульмонология и фтизиатрия / Clinical_Tuberculosis_Friedman_Lloyd_N_,_Dedicoat

The EBUS bronchoscope is similar in dimensions to a standard adult fiber-optic bronchoscope but has an ultrasound probe at its distal end. Proximal to the ultrasound probe, and at 30 degrees to the long axis of the bronchoscope, are a fiber-optic lens and a biopsy channel, through which a 22-G biopsy needle can be passed.

Video-assisted thoracoscopy

VATS can be undertaken with a single 2-cm access port under local anesthesia with the patient breathing spontaneously. However, better access is afforded with greater comfort for the patient and surgeon if general anesthesia and single-lung diagnosis of malignancy or clear proof of TB is found, but if the biopsy reports are of non-specific inflammation, the surgeon will feel that lobectomy is necessary. It is uncertain whether resection in these circumstances speeds resolution of the infective process, but it is certainly preferable to failing to resect a potentially curable cancer. Of course, if TB is established subsequently or seems probable on macroscopic examination of the resection specimen, conventional drug treatment should be started immediately, ahead of culture results.

Lung cancer can occur in conjunction with active TB, or follow years after exposure or effective therapy (Figure 17.7). The

supervising clinician needs to be aware of this possibility if radiological progression is observed despite “adequate” therapy or if “reactivation” is suggested by the development of a new opacity. Many such patients are too frail or have insufficient pulmonary reserve to tolerate resection, but needle biopsy is warranted and effective non-surgical therapy should not be withheld. The fear of reactivation of dormant tuberculous infection by chemotherapy or radiotherapy makes the use of prophylactic anti-tuberculous therapy justified in such circumstances.

MANAGEMENT

Resistant TB

Occasionally, organisms that are sensitive to drug therapy, if sequestered within lung cavities, may not be eradicated by “adequate” drug therapy (Figure 17.8). The surgeon may complete sterilization in such cases by resecting the cavity. For such major surgery, the patient should be in a good nutritional state with adequate lung function to withstand resection and should have had a course of appropriate anti-tuberculous chemotherapy for at least

three months. In practice, in the undernourished subjects who are likely to require such surgery, a considerable period of in-patient preparation will be required to optimize their condition with nutritional support and intensive physiotherapy.7,8

The surgeon will wish to document the full extent of the lung disease before surgery, to see the size and extent of the cavity, to visualize any additional cavities, to anticipate the probable extent of resection and to assess the degree to which fibrosis involves adjacent lung segments. In the past, bronchography was extremely useful in this respect but has now been superseded by CT scanning.

Resection in these circumstances is often technically demand- ing.8–10 The pleural space and fissural planes are usually obliterated by chronic inflammation, and hard, adherent nodes surround the hilar structures. The surgeon’s attempts to be conservative will be made difficult by such problems and by the surrounding fibrosis that usually extends into lung parenchyma beyond the area of the cavity. Careful and technically taxing dissection is necessary. Despite meticulous hemostasis, blood transfusion is frequently required.11

The surgeon must make every attempt to preserve lung tissue that is judged to be recoverable. This will on occasion present

the clinician with the additional problem posed by a small lung remnant failing to fill the hemithorax. The combination of a small residual lung, fibrotic or emphysematous lung parenchyma with a persistent air-leak and the consequent need for prolonged drainage is a recipe for the development of a chronic space infection. The surgeon will wish to avoid this and, if this scenario seems probable, will add a space reduction procedure to the operation, either immediately or after a period of drainage has established the maximal expansion to which the residual lung is capable and defined the extent of chest cavity reduction that is required.5,12

There are a number of such techniques available to the surgeon. A “trimming” thoracoplasty is an old and welltried operation.13 This involves the subperiosteal resection of the upper ribs sufficient to reduce the chest cavity to the size that will accommodate the residual lung. The first rib is removed from the sternum to the neck, protecting the neurovascular structures at the apex and usually two to four other ribs, from the head of the rib forward over a sufficient arc of the rib. The anterior extent of the resection of these ribs is progressively tailored to leave the new apex of the chest cavity configured to the shape of the remaining lung segments (Figure 17.9). In this context, it is not usually necessary to

resect the transverse processes of the vertebrae. The removal of up to three ribs has little cosmetic impact, although physiotherapy is necessary to preserve posture and good shoulder movement, but more than this is probably now unacceptable (Figure 17.10) because other techniques are available.

A pleural tent can be fashioned by extrapleural mobilization over the apex. This produces a hematoma above the tent and will reduce intrapleural volume without irreversibly compressing the lung parenchyma. Unfortunately, in this context, the pleura is usually damaged during dissection and is not available for this technique. The diaphragm may be temporarily paralyzed by cryoablation of the phrenic nerve immediately above its insertion, allowing the diaphragm to rise to obliterate any residual space. Unfortunately, this development of the phrenic crush procedure may not prove adequate if the diaphragmatic position is fixed by chronic inflammation and fibrosis. A myoplastic rotation flap provides healthy tissue to help fill the hemithorax. If the services of an expert reconstructive surgeon are on hand, the ipsilateral latissimus dorsi, the pectoralis major and the serratus anterior, separately or in combination, can be mobilized on their vascular pedicle and transposed into the chest cavity through a short rib resection at an appropriate level.

Although such techniques are technically demanding and require some anticipation on the part of the thoracic surgeon, they provide a good cosmetic result with rapid recovery.14 In practice, a limited “trimming” thoracoplasty combined with a myoplastic flap provides good space reduction with a satisfactory cosmetic result, even if only the basal segments of the lower lobe can be preserved.

Sadly, pneumonectomy will still prove necessary on occasions when all function has been lost on one side and the other lung is normal or the site of minimal disease (Figure 17.11). In such circumstances, it is may be appropriate to undertake pleuropneumonectomy because this facilitates dissection and ensures the clearance of any infected collections within the pleural space. Although the mortality of this formidable operation is now less than 10%,7,9,15 the morbidity remains high, around 30%, chiefly through the development of infective problems often linked with

Figure 17.11  The chest x-ray of a patient with “resistant” TB with extensive destruction of the left lung and minimal disease on the right. Pleuropneumonectomy was performed after three months of drug therapy and resulted in sputum conversion.

bronchopleural fistula (BPF). This complication can be reduced by meticulous surgical technique and the use of pedicled muscle flaps.16 Anti-tuberculous chemotherapy should be continued postoperatively, modified by bacteriological information from the resection specimen. Most authors suggest at least a further six months of drug therapy, although others recommend 12 months.6

Multidrug-resistant TB

Mycobacteria resistant to one or more first-line drugs are now increasingly being encountered in developed countries. Although multidrug-resistant TB (MDR-TB) is relatively uncommon in Northern Europe,17 it presents the most common indication for surgery in TB in North America.12,18 The World Health

Organization (WHO) has issued recommendations for treating (https://www.who.int/tb/publications/2019/consolidated-guide- lines-drug-resistant-TB-treatment/en/); however, most of the evidence is based on case series and expert consensus rather than randomized-controlled studies.19 Surgery is recommended in patients with a high risk of relapse based on drug-resistance profile and persistently positive sputum despite aggressive drug therapy but with localized disease amenable to resection. Prolonged medical therapy is important in the selection and preparation of patients for surgery, and, ideally, sputum conversion should be obtained before an operation.12,18 Patients who do not become sputum-negative and those with residual cavities or destroyed lung parenchyma should undergo surgery, as long as the areas of the lung acting as reservoirs of infection can be encompassed by resection (Figure 17.11).

Those who have widespread, bilateral parenchymal disease are not suitable (Figure 17.12). The risks of BPF make the addition of a myoplastic flap to cover the bronchial stump justified, at least in those undergoing pneumonectomy,12 and some authors would add this routinely to any patient undergoing pulmonary resection for MDR-TB.18 Drugs are continued post-operatively for a prolonged period, but many patients will default despite careful supervision. Prolonged disease control will be achieved with surgery and drug therapy in up to 90% of this difficult population,12,20 an improvement on the high relapse rate seen with medical therapy alone.21

Surgery for the complications of TB

A tuberculous effusion will resolve with drug therapy unless complicated by pyogenic infection, or the development of a BPF, resulting in an empyema. Such septic complications usually occur during the acute illness, but if resolution is incomplete, the presence of a persisting loculus may lead to empyema many years after successful eradication of the tuberculous infection. The treatment of such a complication, whatever the time course, follows the general principles of any empyema: drainage followed by definitive therapy and identify the organism. Occasionally, mycobacteria will be found if

(a)

the original infection was not treated adequately, but usually pyogenic bacteria are responsible. An intercostal drain may be necessary if the patient is toxic and unwell, but in most cases, drainage will be surgical, by rib resection at the most dependent point of the empyema. If this site is not obvious on either CT scan or erect ultrasound scan, a small volume of heavy radio-opaque contrast material will demonstrate the optimal point for drainage on subsequent erect, lateral and postero-anterior chest x-rays.

At the time of drainage, the surgeon will evacuate all fibrin debris and, if there is no clinical or radiographic evidence to suggest a BPF, will irrigate the cavity to clean the space. Such debridement can be facilitated by VATS,22 and at times this may amount to video-assisted decortication.23 Adequate open drainage, given time, will lead to the slow reexpansion of the underlying lung, as long as the lung has fully recovered from the tuberculous infection (Figure 17.13). In frail, debilitated individuals, the clinician may persist with drainage in the hope that resolution occurs or their condition improves sufficiently to allow other options to be considered. Fenestration, the creation of a skin-lined window or Eloesser flap,24 facilitates prolonged drainage without the logistical problems associated with tube drainage.

Definitive surgical treatment will speed re-expansion and resolution of the chronic infection but is dependent upon the fitness of the patient and the state of the lung as assessed by CT scanning. Decortication can be difficult if the visceral cortex is calcified, as may be the case in empyemata that occur many years after the tuberculous infection, and this situation is akin to the problems associated with collapse therapy. If the cortex can be removed, the lung will re-expand if the parenchyma is healthy. If bronchiectasis is present in a segment, lobe or the whole lung, pulmonary resection should be combined with decortication. If the residual lung is too small to fill the hemithorax, due to extensive resection or parenchymal fibrosis, one of the space-filling techniques described earlier will be added to decortication, unless pneumonectomy has proven necessary. Given the bilateral nature of the lung damage that is often present, the surgeon will strive to preserve any functioning lung tissue on the side of the empyema.

(b)

The severity of symptoms may make surgery necessary for some of the other complications of TB.8 A persistent cough, productive of large quantities of purulent sputum, may result from bronchiectasis, destroyed lung parenchyma or may be due to a persistent cavity. Post-tuberculous bronchiectasis usually results in

progressive loss of the lung parenchyma subserved by the affected bronchi and associated atelectasis (Figure 17.14). Resection of such grossly diseased and functionless lung tissue has little impact on residual lung function. Therefore, if the bronchiectatic segments can be encompassed by pulmonary resection, even if this entails

bilateral thoracotomies, surgery offers good symptomatic relief (Figure 17.15). The severity of such disease in each lobe or segment correlates well with the contribution it is making to the patient’s symptoms. On occasion, therefore, it may be justified to remove a grossly diseased lobe, even if areas of minor damage are left in the ipsilateral or contralateral lung. This can be a difficult decision for the surgeon, but in properly selected cases, significant, if incomplete, relief of symptoms can be expected.

Hemoptysis may be small and repeated or dramatic and lifethreatening, and may result from an area of bronchiectasis or destroyed lung, or an uncomplicated cavity. Hemoptysis is much more common and far more problematical when the cavity has been colonized by a fungal ball. Although CT scanning is valuable to demonstrate the presence of fungal colonization of a small cavity (Figure 17.16),25 this is usually obvious on the chest radiograph with large cavities (Figure 17.17). Cough is then also more persistent and especially debilitating when the patient is supine at night.

The technical problems associated with resection for TB, described previously, are even greater in these circumstances, and surgery is only indicated if symptoms are severe. In many patients, the extent of the disease and their poor health will make such surgery excessively hazardous. Certainly a much greater level of fitness is required than would be needed if undertaking

Figure 17.16  The CT scan of an apical mass showing the typical appearances of a fungal ball, allaying suspicions of a neoplasm.25 (From Roberts CM et al. Radiology 165, 123–8, 1987. With permission.)

Figure 17.17  The chest x-ray of a patient with total destruction of the right lung following TB. The largest cavity has been colonized by a large fungal ball. Repeated hemoptysis required pleuropneumonectomy.

the relatively straightforward resection of a cancer. The surgeon should strive to be conservative, using space reduction techniques where appropriate. The mortality rate remains high, usually in the region of 10%6,26 although others have found it as high as 30%.27

In the emergency setting, preparation is denied and the risks are even greater. It is not surprising therefore that bronchial embolization is appealing to patient and doctor alike. Even though some radiologists, with diligence and persistence, have managed good results,28 these are often short-lived, although still of value in permitting surgery to be delayed for more thorough assessment. Surgery, however, is justified in this taxing situation because the risk of further fatal bleeding with medical therapy offsets the appeal of conservative management.29,30

If fungal balls are present bilaterally, the associated widespread parenchymal disease will leave few patients with sufficient respiratory reserve to tolerate complex, bilateral resections. If the

radiologist can identify the bronchial vessel responsible for the hemorrhage, this should be embolized. If not, then all large bronchial vessels will have to be embolized on both sides, taking care to avoid any important spinal branches. Success in such circumstances is lower, but one has little option in such dire situations. The risk of bleeding seems related to the size of the cavity not the fungal ball.29 Therefore, if the cavity on one side is considerably larger than on the other side, and if the patient is fit for unilateral surgery, then the clinician may be forced to undertake the speculative resection of the dominant lesion in the hope of salvaging the patient.

For patients in whom embolization has failed repeatedly, and who are unfit for conventional surgery, the surgeon may have to resort to unconventional techniques. Injecting antifungal agents such as brilliant green, natamycin and “Polish paste” into the cavity, bronchoscopically or percutaneously, has been advocated,31 but the results are unconvincing. Cavernostomy has been tried in the emergency setting with limited success.32 Cavernostomy in the elective situation is successful at relieving cough and less dramatic bleeding, and the cavity may remain radiologically free of colonization. Transposing a myoplastic flap into the cavity seems to be beneficial even if the flap fails to fill all the interstices of the cavity. Perhaps the muscle with its blood supply exudes cytokines that prevent further colonization. Simultaneous thoracoplasty to collapse the cavity should also be considered.33

Endobronchial TB can result in bronchial stenosis and subsequent destruction of the subserved lung parenchyma. If medical therapy with the addition of steroids does not lead to resolution, early recourse to surgery is necessary to preserve lung function.34,35 Conservative surgery is often possible, and bronchoplastic repair will conserve some or all of the lung parenchyma (Figure 17.18).

Surgery for the late sequelae of collapse therapy

We are often haunted by our successes. Patients who had cavitating TB in the 1940s and early 1950s and were salvaged from this dismal situation by “novel” collapse procedures may return in their twilight years with the late, infective complications of induced pneumothorax, extrapleural pneumothorax, plombage (Figure 17.19) or

(a)

(b)

Figure 17.18  (a) A spiral CT reconstruction of a patient who suffered tuberculous endobronchial infection showing stenosis of the termination of the left main bronchus. (b) The scan also confirmed damage to the left upper lobe by obstruction with subsequent bronchiectasis. Bronchoplastic resection of the main bronchus with upper lobectomy restored function to the lower lobe and prevented progressive loss of the whole lung.

an inadequate thoracoplasty. The responsible clinician, and even the patient themselves, may overlook the distant history. Indeed, many of the doctors treating such patients would not have been born at the time of the initial treatment. As a consequence, it is not unusual for such problems to be undiagnosed for many months or dismissed as chest infections or simple empyema.

Once considered, the diagnosis is not difficult and CT scanning will confirm the situation (Figure 17.20). The intrathoracic space will be seen on serial chest x-rays to have enlarged (Figure 17.21) or to have developed a fluid level (Figure 17.22). The infective agent is usually a pyogenic organism, such as Staphylococcus aureus, but myobacterium TB may be present and may require additional drug therapy. Surgical management is complex and further complicated by the age and frailty of many patients. Initial

drainage should be performed surgically. Any foreign material is removed from the pleural cavity, which is not difficult if polystan or lucite balls had been used but can be more troublesome if shredded plastic had been inserted without an envelope (Figure 17.21). Subsequent management, and its timing, will depend upon the level of fitness achieved following drainage and the patient’s attitude to long-term drainage. If they are sufficiently fit to be offered a permanent solution, most will opt for surgery, despite the obvious risks. If the underlying lung is of reasonable volume and CT suggests it has recovered well from the initial infection and years of collapse, decortication may be attempted. Usually, however, this alone will prove inadequate. The lung may fail to fill the hemithorax, or surgical trauma will leave an excessive airleak. Space obliteration by myoplasty and/or omentoplasty is often necessary, often combined with a “trimming” thoracoplasty that

reduces the cavity to be filled and allows access for the muscle flap. The omentum is particularly well suited to this situation because of its ability to “mop up” infection and adhere to the underlying lung. A pedicled, rotation flap of omentum may not reach the apex of the chest cavity (Figure 17.23). The addition of a myoplastic flap, based on pectoralis major or serratus anterior, may serve to fill this part of the cavity or the technically more demanding technique of a free graft of omentum may be necessary, using microsurgical re-anastamosis of the vascular pedicle of the omentum to a suitable artery and vein in the thorax, usually the internal mammary vessels.14

A shallow, infected pneumothorax cavity may be treated by a localized, Schede type of thoracoplasty13 with little impact on functional or cosmetic result (Figure 17.24). More extensive thoracoplasty operations of this type are complicated by the subsequent

Figure 17.22  The chest x-ray of a patient presenting with fever, cough and hemoptysis 35 years after right extrapleural pneumothorax and right-sided plombage. The fluid level indicates the infection is within the right space.

onset of respiratory failure as a consequence of denervation of the accessory, abdominal muscles of respiration. Revision of the original thoracoplasty may eradicate the residual space (Figure 17.25). If the patient is unfit for definitive surgery, then the options are limited. Long-term drainage requires domiciliary nursing care, and the patient may prefer a fenestrum or Eloesser flap procedure.24 The best quality of life may be afforded by leaving nature alone and the patient with an intermittent discharging sinus.

Diagnostic procedures for TB, such as mediastinoscopy and VATS, can be performed virtually without risk if the patient is reasonably fit and the surgeon experienced with such techniques,2 but the risks increase as the procedure becomes more invasive and resection becomes necessary. In such circumstances, considerable experience is necessary to select and prepare the patient and to choose the appropriate technique from the wide range of options available. Although lesser resections can be performed with an operative mortality less than 5%,6,8 if operating for the severe complications, such as fungal infection especially with massive hemoptysis, or if pneumonectomy proves necessary, expert surgery is needed to keep the mortality around 10%.6,9,26 Such surgery is technically challenging but worthwhile in the desperate situation faced by such patients.

Our approach to infection control and surgery for MDR-TB

When performing surgery on patients with MDR-TB, in addition to achieving the desired outcome for the patient, the surgical and anesthetic teams must minimize the risk of infection for the staff and other patients. This can only be achieved by ensuring there is good prior preparation, involvement of the infection control team and co-ordinated teamwork. All staff present in the operating room will have fit testing performed with retraining as necessary to ensure correct wearing of filtering facepiece (FFP) masks. Traditionally, operating rooms are positive pressure ventilated with air being pushed out of the room into the surrounding corridors. In MDR-TB cases, it would be ideal to have a negative pressure operating room to allow potentially contaminated air to be removed safely and further reduce risk to staff.36

Our patients usually come to the operating theater wearing an FFP2 or FFP3 mask. All staff present in the theater will also don FFP2 or FFP3 masks prior to the patient removing their mask. During the procedure, we minimize staff leaving and re-entering

the operating room by ensuring that whenever possible all equipment is available either in the theater or in the adjacent anteroom/ preparation room. We have found however that if the surgery is prolonged, staff wearing FFP masks for sustained periods find this tiring and many have reported developing headaches or feeling uncomfortable. Non-scrub staff may leave the theater for a comfort break; however, the scrub team normally does not; therefore, we normally wear FFP 2/3 masks with an exhale valve to reduce this effect.

After removal of the patient’s FFP mask, the patient will breathe oxygen/air mix as appropriate using a face mask connected to the anesthetic machine circuit with waste gas being extracted via a scavenging system. Following induction of anesthesia, our patients always have a bronchoscopy performed. Our preference is to perform a rigid bronchoscopy followed by passage of a flexible fiber-optic bronchoscope via the rigid bronchoscope. Video bronchoscopes allow the surgeon to avoid placing their face near to the patient’s face. The combination of rigid and flexible bronchoscopy allows very good rapid clearance of any retained secretions and thorough inspection of the bronchial tree to identify the anatomy