**Lung Transplantation**

Wickii T. Vigneswaran

*Lung and Heart-Lung Transplantation, University of Chicago, USA* 

#### **1. Introduction**

#### **1.1 History**

The foundation for lung transplantation was laid in the early 1900 by Guthrie and Carrel. In recognition of his work in vascular anastomosis, Dr. Carrel received the first Nobel Prize in Medicine. Following this early work, in 1946 Demikov in Russia performed a canine lung transplant as a unit. The dog subsequently died of bronchial dehiscence. The first human lung transplant was performed by Hardy at the University of Mississippi in 1963. Patient survived a few days and succumbed to complications. Derom in Belgium was credited with the first successful human lung transplantation when he reported 10 month survival of a patient who had undergone lung transplant for end-stage pulmonary fibrosis in 1971. By 1978, 38 lung transplants had been performed worldwide but Derom's patient was the only one that had approached a beneficial outcome. Consistently noted poor outcome in the 60s and 70s led to a moratorium on clinical lung transplantation in the late 70s. Rejection and infection were the common causes of death in this early group and bronchial anastomotic healing was the barrier for transplant survival beyond 2 weeks (1).

Cyclosporine based immune suppression in kidney and liver transplantation in the early 1980s resulted in dramatic improvements in organ function and patient survival. With this experience Shumway and Reitz successfully transplanted heart-lung blocks using a cyclosporine based immune suppression on primates. Airway complications were rare in heart-lung transplantation due to the non coronary collaterals, where as this was a major drawback of isolated lung transplantation. The success of the Stanford group led to the reinstitution of clinical heart-lung transplantation in the 80s (2).

Meanwhile in Toronto, significant experimental work were done by Pearson and Cooper to solve the bronchial healing problem in animal models. The technique of omental wrap around the bronchial anastomosis was developed by Cooper et al. In 1986 the Toronto Lung Transplant Group reported successful single lung transplantation for pulmonary fibrosis in two patients (3). Technique of en-bloc double lung transplant failed due to the tracheal anastomotic complication related to ischemia. Finally bilateral sequential transplantation was developed as a method of transplanting both lungs without the heart. Currently around 147 centers perform over 2000 isolated lung transplants a year. The bronchial anastomotic technique has evolved since and bronchial wrapping is no longer considered necessary.

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improvements in clinical results and shortage of donor organs the generally accepted donor criteria are continually being challenged and expanded. Donor lung selection also depends on subjective assessment at the time of exploration in the operating room and judgment of

The donor pneumonectomy is approached via a midline sternotomy. The lung is inspected to evaluate its suitability for transplantation by the donor surgical team. Heparin is administered and a pulmonary plegia cannula is inserted into the main pulmonary artery ensuring both main pulmonary arteries are perfused by the cannula. A clamp is placed on the left atrial appendage and the tip of the appendage is excised for free drainage of the pulmonary effluent during the pulmonary plegic infusion. Prostaglandins and pulmonary vasodilators are administered into the main pulmonary artery followed by cold pulmonary plegia that also contains vasodilator medications. The lung is inflated to moderate amount and the trachea is stapled with lung inflated. The lung block is dissected away from the mediastinal structure with the heart or separately after the heart is excised by the 'cardiac' team. Left atrium is divided midway between the confluence of the pulmonary veins and the atrial groove ensuring that an adequate "atrial cuff" will be available with the lungs for implantation. The ligamentum arteriosum is divided toward the descending aorta avoiding injury to the left main pulmonary artery and the entire lung block is dissected away from the descending aorta and esophagus. The lungs are separated from each other at the back table by dividing the left main bronchus with the staples, pulmonary artery at the bifurcation, and left atrium between the right and left pulmonary veins. Retrograde cold flush of the preservation solution is performed through the pulmonary veins before packaging the organs in sterile fashion for

Satisfactory early and midterm outcomes had been reported with using lung donation after cardiac death expanding potential lung donors (10). Recent exciting developments on normothermic ex-vivo perfusion allowing repair of injured lung and the ability to evaluate function of the lung prior to transplantation has potential benefit of increasing the donor

Once a donor is verified and deemed suitable for transplant, the recipient is brought into the operating room for transplantation (12). Generally the contra-lateral lung is used to support the recipient during the transplantation procedure. Some patient will require

the donor surgical team (6).

pool even further (11).

ABO Compatibility Clear Chest Radiograph

Tobacco history < 20 pack years Absence of significant chest trauma

Prior cardiopulmonary surgery Presence of lung pathology on CT scan

**3.2 Recipient operation 3.2.1 Single lung transplant** 

Age < 60

transportation to the recipient operating room (8,9).

PaO2 > 300 on FIO2 = 1.0 and PEEP of 5 cm H2O

Table 1. Established Criteria for Donor Selection

No evidence of sepsis or blood borne infections (Hepatitis B, C or HIV)

Purulent secretion on bronchoscopy or evidence of aspiration
