Sequential bilateral isolated lung perfusion in the rat: an experimental model

In situ methods for assessing alveolar mechanics

Lung mechanics are an important determinant of physiological and pathophysiological lung function. Recent light microscopy studies of the intact lung have furthered the understanding of lung mechanics but used methodologies that may have introduced artifacts. To address this concern, we employed a short working distance water immersion objective to capture confocal images of a fluorescently labeled alveolar field on the costal surface of the isolated, perfused rat lung. Surface tension held a saline drop between the objective tip and the lung surface, such that the lung surface was unconstrained. For comparison, we also imaged with O-ring and coverslip; with O-ring, coverslip, and vacuum pressure; and without perfusion. Under each condition, we ventilated the lung and imaged the same region at the endpoints of ventilation. We found use of a coverslip caused a minimal enlargement of the alveolar field; additional use of vacuum pressure caused no further dimensional change; and absence of perfusion did not affect alveolar field dimension. Inflation-induced expansion was unaltered by methodology. In response to inflation, percent expansion was the same as recorded by all four alternative methods.

Isolated lung perfusion for pulmonary metastases

Isolated lung perfusion is an experimental surgical technique evaluated for the delivery of high-dose chemotherapy to improve 5-year survival after pulmonary metastasectomy. Extensive experimental work in animal models has demonstrated superior pharmacokinetics and efficacy compared with systemic therapy. Phase I clinical trials of isolated lung perfusion found a maximum tolerated dose**** of TNF-alpha, doxorubicin, cisplatin, and melphalan, whereas the combination of isolated lung perfusion with a complete metastasectomy was feasible. The combination of isolated lung perfusion and regional lung perfusion techniques needs further investigation.

Pharmacokinetics after Endovascular Lung Perfusion with Cisplatin

PURPOSE

Endovascular lung perfusion (ELP) is a technique designed to deliver high doses of cisplatin via the pulmonary artery for the treatment of lung tumors. The purpose of the current study was to evaluate variables that affect adduct formation.

MATERIALS AND METHODS

Thirteen swine underwent ELP. The first group (n = 6) underwent infusion of 150 mg cisplatin diluted to 0.5 mg/mL via a balloon occlusion catheter in the left pulmonary artery. Uptake was compared with that seen with systemic infusion. A second group (n = 7) underwent bilateral sequential infusion of the left pulmonary artery, followed by the right. Cisplatin (150 mg) was infused at one of three concentrations: 1 mg/mL (n = 5 lungs), 0.67 mg/mL (n = 5 lungs), or 0.5 mg/mL (n = 4 lungs). The Pearson coefficient was used to correlate uptake with infusion time, infusate concentration, animal weight, and initial mean pulmonary artery pressure.

RESULTS

In the first group, cisplatin uptake in the control lung was less than 8% of that in the study lung. Infusion times for both groups ranged from 3 minutes to 56 minutes. Increases in infusion time correlated with increased adduct levels (r = 0.831; P < .0001). Mean uptake at concentrations of 0.5, 0.67, and 1 mg/mL were 25.79, 12.43, and 13.12 fmol/mug, respectively. There was no significant correlation between pulmonary adduct levels and infusate concentration (r = 0.106; P = .72). Animal weight and initial mean pulmonary artery pressure were not correlated with adduct formation.

CONCLUSIONS

ELP with longer infusions of cisplatin may lead to greater adduct formation in pulmonary tissues. Changes in concentration of the infusate do not affect uptake of cisplatin. Hemodynamic parameters do not affect cisplatin uptake.

Isolated lung perfusion for the treatment of pulmonary metastases current mini-review of work in progress

Surgical resection of lung metastases is a widely accepted procedure but long-term results are disappointing with a 5-year survival rate of approximately 40%. Pulmonary metastasectomy is only indicated when complete resection can be achieved. A better survival is reported in patients with a single metastasis or a disease-free survival of more than 3 years. Intravenous chemotherapy has no major impact on survival because high-dose therapy is limited by systemic side-effects. Isolated lung perfusion has the advantage of both selectively delivering an agent into the lung while diverting the venous effluent. This allows the drug to be given in a significantly higher dose compared to intravenous therapy, while drug levels in critical organs are kept low enough to avoid significant morbidity. Isolated lung perfusion has proven to be effective for the treatment of lung metastases in animal models while the procedure is technically safe in humans. However, the real clinical value and survival benefit remain to be determined in ongoing clinical trials.The aim of this paper was to update the literature on isolated lung perfusion for the treatment of lung metastases. Furthermore, some proposals are made in order to improve the ultimate prognosis of these patients.