Transbronchial Biopsies With Cryoprobe in Patients With Lung Transplantation.

Prospective Study of Transbronchial Biopsies With Cryoprobe in Patients With Lung Transplantation Admitted to an Intensive Care Unit.

The survival of lung transplant patients (PD) is limited mainly by Infections, graft dysfunction in the immediate postoperative period and chronic dysfunction. Up to 36% have an episode of acute rejection after transplantation. For the diagnosis of these pathologies, transbronchial lung biopsy (BPTB) is essential. The classical method is the realization of BPTB with conventional clamp, but the performance diagnosis is limited. However, the use of cryoprobes for sampling in other pulmonary pathologies have been shown to achieve a higher diagnostic yield. The BPTB performance is variable and depends on factors such as sample size and the presence of artifacts (crushing) produced by the forceps tweezers. The objective principal is to compare the diagnostic yield of samples obtained with cryoprobe compared to those obtained with conventional biopsy tweezers. A prospective, randomized, and comparative study is proposed for all patients in the intensive care unit after lung transplantation in a 24-month period, at Vall de Hebron Hospital. Patients will be divided into two groups: symptomatic and asymptomatic. The exclusion criteria are the contraindications of the procedure and the factors which increase the hemorrhagic risk. A flexible bronchoscope (BF-18BS) will be used and the procedure will be performed according to the technique conventional. The patient undergoing the procedure will be intubated, sedated and relaxed under supervision and continuous monitoring by an intensivist. A bronchoalveolar lavage and a maximum of 6 samples will be obtained. Morphological study (middle area, artifacts, components, diagnosis), microbiological, histological and anatomopathological according to the usual protocol. The duration of the procedure, the complications and the frequency with which the diagnosis obtained after the procedure modifies the therapeutic behavior will be monitored. These data will allow to evaluate the potential benefits of this procedure in the diagnosis of pulmonary pathology in lung transplantation.

Bronchoscopic examinations will be performed with intubated patients under continuous monitoring (pulse oximetry, blood pressure, heart and respiratory rate), Oxygen therapy with high flows and surveillance by anesthesiologist. The bronchopulmonary lobe where the biopsies will be performed is determined prior to the procedure based on an imaging study (chest x-ray or computed tomography). Transbronchial biopsies will be obtained using a flexible bronchoscope (Pentax, 3.2 mm working channel), which approaches the subsegment where the affected area is located. The 2.4 mm diameter cryoprobe is placed (Erbokryo®), and moves forward until it encounters a soft resistance. The cryoprobe is removed between 5-10 mm and the freezing is applied for 3 seconds. After 3 seconds, the probe is gently removed together with the bronchoscope and frozen tissue sample at the tip of the probe. In the case of strong resistance, the process is stopped and then repeated. In the case of the use of forceps, the conventional technique is used.

Inclusion Criteria:

• Pulmonary transplant patients admitted to the intensive care unit who are assigned a transbronchial lung biopsy.

Exclusion Criteria:

• Respiratory insufficiency refractory to oxygen therapy.
• Acute or subacute ischemic heart disease.
• Severe arrhythmias.
• Coagulation disorders: platelets < 60,000-50,000 or Prothrombin time > 60%.
• Lack of informed consent.