High Yield Mycobacterium: TB & Non-TB Flashcards
Treatment of drug-sensitive tuberculosis is largely.
Treatment of drug-sensitive tuberculosis is largely medical, with high cure rates, if adequate therapy is delivered.
Antibiotic regimen for drug-sensitive tuberculosis
The initial prescribed treatment for active tuberculosis is a 6- to 9-month regimen consisting of four drugs: isoniazid, rifampin, pyrazinamide, and ethambutol.
With this regimen, almost 90% of patients have bacteriologically negative sputum at the end of the 6-month period.
Antibiotic regimen for drug resistent TB:
- The treatment of drug-resistant tuberculosis is complex, and is frequently changing, but typically consists of 4-5 drugs from different classes of medications.
- Newer drugs such as bedaquiline (a diarylquinolone antibiotic) and pretomanid/delamanid (a mycobacterial cell wall synthesis inhibitor) have also begun to be incorporated into MDR-TB regimens, particularly in combination (linezolid/bedaquiline/pretomanid).
Patients with latent tuberculosis who are at high risk for progression to tuberculosis disease, such as patients with HIV infection and those who are at increased risk for recent infection (e.g., contacts of patients with tuberculosis), are treated with:
Patients with latent tuberculosis who are at high risk for progression to tuberculosis disease, such as patients with HIV infection and those who are at increased risk for recent infection (e.g., contacts of patients with tuberculosis), are treated with 9 months of isoniazid.
Treatment of NTM Cervical Lymphadenitis
NTM cervical lymphadenitis is due to MAC in the majority of cases and treated primarily by surgical excision, with a greater than 90% cure rate. A macrolide-based regimen should be considered for patients with extensive MAC
Indications for surgery:
- Massive Hemoptysis
- Bronchopleural fistula
- Bronchial stenosis
- Trapped Lung
- Cavitary lesions/areas of destroyed lung failed medical therapy
- Extensive drug resistance
- Superimposed Fungal infection
- r/o cancer
Most common indication for surgery
For non-tuberculous mycobacterium (NTM)
For non-tuberculous mycobacterium (NTM), failure of medical treatment and symptom relief are the most common indications for surgery
TB and non-tuberculous mycobacterium (NTM)
Goal of surgery:
In most cases of NTM or TB, the goal of surgery is:
To remove focal, persistent lung damage (bronchiectasis, cavitation, consolidation or destroyed lung) amenable to anatomic resection
Anatomic resection poses increased technical complexity as compared to surgery for cancer, due to:
Anatomic resection poses increased technical complexity as compared to surgery for cancer, due to
- pleural symphysis
- adhesions
- bronchial circulation hypertrophy
- chronic hilar fibrosis associated with lymphadenopathy
ATS/IDS Guidelines for NTM Treatment.
Nodular/bronchiectatic disease
Nodular/bronchiectatic disease:
a three-times-weekly regimen of :
- clarithromycin (1,000 mg) or azithromycin (500 mg),
- rifampin (600 mg), and
- ethambutol (25 mg/kg) is recommended.
ATS/IDS Guidelines for NTM Treatment.
Fibrocavitary MAC or severe nodular/bronchiectatic disease:
Fibrocavitary MAC or severe nodular/bronchiectatic disease: a daily regimen of
- clarithromycin (500–1,000 mg) or azithromycin (250 mg),
- rifampin (600 mg) or rifabutin (150–300 mg), and
- ethambutol (15 mg/kg)
- with consideration of three times- weekly amikacin or streptomycin early in therapy is recommended.
Patients should be treated until culture negative on therapy for 1 year.
The minimum evaluation of a patient suspected of NTM should include the following
- chest radiograph or, in the absence of cavitation, chest CT scan
- three or more sputum specimens for acid-fast bacilli (AFB) analysis
- exclusion of other disorders, such as tuberculosis (TB).
Name the prior procedure:
Plombage with Lucite balls
Complications of Prior Surgery for TB
Plombage
- Erosion into surrounding structures
- Migration
- Infection of the foreign material
- Tension pleural effusion
- Malignancy
Complications of Prior Surgery for TB
Treatment of an infected plombage space or of migration of plombage material consists of:
Treatment of an infected plombage space or of migration of plombage material consists of:
- removal of the foreign bodies
- empyemectomy
- thoracoplasty with or without the use of muscle transposition to fill the residual space
Define:
- Multidrug-resistant tuberculosis (MDR-TB)
- Extensively drug-resistant TB (XDR-TB),
- Multidrug-resistant tuberculosis (MDR-TB), defined as TB resistant to at least isoniazid (INH) and rifampin (RIF),
- extensively drug-resistant TB (XDR-TB), defined as resistance to INH and RIF plus at least one fluoroquinolone and one second-line injectable drug
Principles of surgical resection (2)
- The most important surgical principle of pulmonary resection for tuberculosis is to remove all gross disease while leaving enough tissue for adequate pulmonary function.
- Another important principle is to undertake lung resection** only in patients who have converted their sputum. ** (Sputum negative)
In general, three criteria can be used to evaluate for the use of surgery in Multidrug-resistant tuberculosis (MDR-TB):
- Drug resistance and high probability of failure,
- Localized disease amenable to resection
- Enough drug reactivity to allow healing infected bronchial stumps.
* The optimal duration of preoperative and postoperative chemotherapy is still debated, but the presence of negative cultures at the time of surgery clearly decreases operative morbidity and mortality.
* For this reason, prior medical treatment of at least* 3 to 6 months is recommended.
Duration of medical therapy after surgery - Culture negative
- Susceptible TB
- MDR TB
- XDR TB
If the patient is culture-negative at the time of surgery for
- susceptible TB, at least four months of postoperative treatment is recommended
- TB is MDR or XDR, then six to eight months of treatment is recommended postoperatively.
Duration of medical therapy after surgery - C ulture positive
- Susceptible TB
- MDR TB
- XDR TB
For culture-positive patients at the time of surgery,
- with susceptible TB, four to six months of treatment after culture conversion;
- with MDR-TB, at least 18 months after culture conversion;
- and with XDR-TB, at least 24 months after culture conversion.
Superimposed Fungal Infection
Fungal disease in the setting of destroyed lung secondary to TB is most commonly cause by?
Fungal disease in the setting of destroyed lung secondary to TB is most commonly cause by Aspergillus
- Of patients with with destroyed lung due to pulmonary TB, about 15% are thought to develop mycetoma.
Rasmussen’s aneurysms
In addition, the incorporation of pulmonary artery branches into the wall of tuberculous cavities causes small dilations of these vessels, which are referred to as Rasmussen’s aneurysms
Most patients with hemoptysis and active tuberculosis bleed because of the development of:
Most patients with hemoptysis and active tuberculosis bleed because of the development of systemic bronchial circulation around the infected sites.
In addition, the incorporation of pulmonary artery branches into the wall of tuberculous cavities causes small dilations of these vessels, which are referred to as Rasmussen’s aneurysm
Bleeding from tuberculous lesions is usually the result of:
Bleeding from tuberculous lesions is usually the result of bronchial ulcerations into bronchial arteries or into Rasmussen’s aneurysms.
Occasionally, bleeding is secondary to necrosis of small branches of pulmonary veins; erosion of old, calcified nodes through a bronchus (broncholith); or acute tuberculous ulcerations of the bronchial mucosa.
Surgical Options for Cavernoma when resection is not an option.
- Thoracoplasty combined with muscle plombage may be useful to collapse the cavern.
- Another option is cavernostomy or a Monaldi procedure.
Tracheoesophageal or Bronchoesophageal Fistula
Pathphysiology of fistula formation
In these cases, the fistulas are produced by the continuous pressure on and scarring of infected mediastinal nodes located between the trachea and the esophagus.
The anatomic locations of fistulas are variable; they have been reported at the levels of the trachea, right main stem bronchus, left main stem bronchus, and right lower lobe bronchus.
Tracheoesophageal or Bronchoesophageal Fistula
Treatment
- Unless surgery is urgently required, a trial of medical therapy seems to be a reasonable first-line approach because some of these fistulas heal with medical therapy alone.
- Patients with significant associated esophageal or bronchial stenosis and patients in whom the diagnosis of malignancy cannot be excluded might require surgery.
- Correction requires closure of the esophageal defect, segmental resection of the trachea, and tissue interposition.
Bronchiectasis
Clinical presentation and management
- the clinical presentation is most commonly in the form of hemoptysis.
- Unless the hemoptysis is massive, patients need to be considered for surgery only after a long trial of medical therapy.
- If the hemoptysis is recurring despite adequate medical management, surgical resection is considered,** particularly if the bronchiectasis is localized and if resection is likely to result in complete removal of the disease **
Extrinsic Obstruction by Tuberculous Lymph Nodes
Management
Extrinsic airway obstruction is usually responsive to medical therapy, primarily to corticosteroids.
In the rare cases in which the obstruction becomes clinically significant, surgical decompression may be necessary.
Endobronchial Tuberculosis and Bronchostenosis
- Location
- Treatment
- The lower and middle lobes are more commonly affected than the upper lobes.
- Surgical treatment needs to be based on the general status of the patient and the location of the stenosis. Balloon dilation, metallic stenting, laser vaporization, and bronchoplastic resection have been accomplished with good results. To prevent relapses or restenosis, continuous antituberculous chemotherapy is given for 9 - 12 months postoperatively.
Middle Lobe Syndrome: TB
Define
- The syndrome is caused by extrinsic nodal compression of the bronchus of lingula or middle lobe, which results in post-obstructive atelectasis and chronic pneumonitis.
- the middle lobe and lingula are particularly susceptible because of the long and narrow bronchus and the absence of collateral ventilation in patients with complete fissures, combined with the collar of lymphatic tissues at the neck of the bronchus in these locations.
Middle Lobe Syndrome: TB
Management
- In patients with middle lobe syndrome, it is important to rule out endobronchial obstruction by a malignant neoplasm, which could produce the same radiologic appearance.
- Once the diagnosis of benign disease has been established, patients are screened for tuberculosis, and symptomatic patients who are fit for surgery undergo pulmonary resection.
TB: Bronchopleural Fistula
Initial Management
- The initial management of tuberculous bronchopleural fistula consists of tube drainage and antibiotic therapy. Although tube thoracostomy has been used on a permanent basis, it is usually a temporary measure that allows rapid resolution of sepsis and optimal preparation of patients for more definitive therapy.
- In elderly patients with chronic sepsis and in patients with HIV/AIDS, open drainage by way of a thoracic window is an alternative.
TB: Bronchopleural Fistula - Surgical therapy
- Timing/preperation
- Objectives of surgery
- Once drainage of the pleural cavity has been established, sepsis is under control, and tuberculosis is adequately treated medically, low-risk patients can be offered permanent repair of the fistula.
- Preparation for this can take 3 - 6 months because patients with ongoing active tuberculosis at the time of surgery have higher risks for surgical complications in the form of pleural empyema and dehiscence of the repair. Nutrition and antituberculous therapy must be aggressively optimized.
* The objectives of surgery are threefold: 1) to close the fistula, 2) to re-expand the lung via decortication if needed, and 3) to fill the space either by re-expanded lung or by vascularized muscle or omental flaps.
* the bronchial stump is always reinforced with viable vascularized autografts
Pleural Tuberculosis with Effusion
Pleural fluid analysis
- Pleural fluid protein and lactate dehydrogenase are elevated
- the pH is less than 7.4
- the glucose concentration is approximately 60 mg/dL.
- The total cell count is usually fewer than 6000/μL, the cell population being predominantly T lymphocytes, with an absence of mesothelial cells.
- Pleural adenosine deaminase levels, usually in the range of >50, can be used as a diagnostic aid as well
Pleural Tuberculosis with Effusion
Management
- Surgical drainage of the pleural space is performed only in patients who have large effusions.
* Failure of pulmonary expansion after adequate medical therapy can occur in a significant proportion of patients. In young, fit patients with significant restriction, decortication may be indicated. - The management of pleural tuberculosis is otherwise mainly medical. Treatment with two drugs for a period of 9 months is recommended.
Pleural Tuberculosis with Empyema
Management
In this condition, tube thoracostomy with negative suction is used first, but if lung expansion cannot be obtained, open decortication may become necessary.
Preperation (Abx) for surgery in non-tuberculous mycobacterial (NTM) infection
- Targeted antimycobacterial therapy, often including intravenous or inhaled aminoglycosides, should be administered for at least 2 to 3 months before surgical intervention.
- This duration aims to reach a nadir in organism counts before surgery and in many cases dictates the timing of surgery.
Indications for surgery in non-tuberculous mycobacterial (NTM) infection
Three main indications exist –
1) failure of medical therapy,
2) for relief of intractable symptoms (cough/recurrent hemoptysis)
3) in select cases, to limit progression.
* An example of this would be a patient with a destroyed lung on one side, and limited parenchymal disease in the contralateral lung. Resection of all areas of lung disease might be impossible, but the patient would clearly benefit from removal of the destroyed, nonfunctional lung to limit “spillage” into the better lung from infected cavities.
Most common indication for surgery in non-tuberculous mycobacterial (NTM) infection
- Most commonly surgery is performed to clear focal, residual disease after medical therapy.
- Persistent lung damage (bronchiectasis, cavitation, consolidation and destroyed lung) amenable to compete anatomic resection after initiation of appropriate antimicrobial therapy represents the most common indication for surgery in NTM.
Technical Challenges and Considerations During Anatomic Resection
Concern for contamination of the contralateral lung. Mgmt of the bronchus.
On top of this, the surgeon must be wary of contamination of the contralateral lung. To this end, It may be beneficial to attempt to approach the bronchus and control it first, which is a change from a standard VATS approach for cancer for example where the bronchus would be controlled last.
Managing the Pneumonectomy Space and BPF
Indications for flap coverage?
. Indications for flap coverage include poorly controlled infection, drug resistant organisms, and pneumonectomy especially those done on the right side.
Managing the Pneumonectomy Space and BPF
Pleural space mgmt
Managing the pneumonectomy space is controversial, however, in the face of gross contamination it may be necessary to take preventive measures against post-pneumonectomy empyema.
Many methods have been employed, which range from continuous irrigation of antibiotic and antituberculous chemotherapy to simple tube drainage.
Managing the Pneumonectomy Space and BPF
Bronchopleural fistula Mgmt
- The mainstays of treatment are tube drainage, antibiotics and antituberculous therapy, protection of the contralateral lung and stabilization of the patient.
- This is followed by operative drainage of the chest with either the accelerated treatment (the Weder procedure), or creation of an Eloesser flap, depending on the timing of occurrence, stability of the mediastinum, patient condition and surgeon preference and comfort with the techniques.
Name the procedure
Patient is placed in anterolateral decubitus position. The previous thoracotomy (generally an anterolateral incision) was reopened, and a radical debridement of the
pleural cavity by partial pleurectomy and curettage of all necrotic and fibrous infected tissue was performed and followed with irrigation.
The presence of minor BSI wasconfirmed by flooding the chest cavity with saline and
observing escaping air bubbles from the mediastinum. If present, the BSI was closed through various techniques and secured by omentopexy.
Weder procedure
Managing the Pneumonectomy Space and BPF
Uncontrolled sepsis with positive sputum cultures. Surgical consideration.
Flap coverage should be considered in these cases with either intercostal muscle, posterior pleura, muscle from the back (latissimus or serratus), or even omental coverage
TB in Children
TB in Children
Indications for Surgery: TB
Indications for Surgery: NTM
Indications for Surgery: MDR-TB
Name the procedure
Eloesser Flap Thoracostomy Window
Name the procedure
Claggett Window
Name the procedure
