Weissberg
et al.[
12] described seven patients with severe sepsis not suitable for surgery. Prompt clinical recovery post-PTD was reported in all patients with complete resolution of abscesses within 4–24 days without complications. Shim
et al.[
3] also reported the result of PTD in four patients with refractory lung abscesses; all patients defervesced promptly and all cavities closed over 6–12 weeks. The patients tolerated the tube drainage well and there were no side effects.[
3]
Another advantage of PTD is rapid clinical and radiological improvements in pyogenic lung abscesses, and thus, the avoidance of potential complications associated with conservative and prolonged treatment. Van Sonnenberg
et al.[
23] reported a 100% cure rate in 19 unresponsive patients treated with CT-guided PTD. The average duration of drainage was 9.8 days, while hemothorax was reported in only one patient. Ha and colleagues reported complete abscess resolution in four of six patients treated with small catheters; the mean drainage duration was 15.5 days.[
26] One of the remaining two patients showed a partial response and the other did not respond. The failure of PTD in the latter case was due to recurrent aspiration; no complications were related to the procedure itself.[
26]
On the other hand, in one study, the incidence of secondary surgical resection after primary drainage was 11% in 295 patients.[
19] This is close to twice the number seen among the 124 cases reviewed in this article, which was 6.5% (8/124); this indicates that PTD is becoming more effective, thus avoiding the need for more invasive procedures.
Although most studies demonstrated good results with PTD, it should be emphasized that the efficacy of this procedure is still being debated, and it is not always successful. Most recently, Yunus reported 19 cases with lung abscesses treated using CT-guided PTD.[
29] The success rate was 79% and the complication rate, 60%. In a cohort study, Hirshberg and colleagues attempted PTD in 11 patients; the procedure was technically successful in eight patients only, and five of these patients died.[
8] Factors that may lead to failure of PTD may include secondary lung abscess, co-morbid illnesses, virulent organisms, multiloculation, poor definition of the cavity, and a thickened wall cavity that may not collapse.[
4,
8]
Single percutaneous aspiration of abscess contents could also be therapeutically successful. In one study, after the failure of medical therapy, single percutaneous aspiration was performed in 10 patients.[
30] Nine of these responded and recovered completely, while the remaining patient required percutaneous drainage.[
30] In addition, percutaneous aspirate cultures were often diagnostic and informative, and hence, the treatment plan could be modified accordingly. Yang
et al. described 10 patients (43%) whose antibiotic regimen was changed based on the results of percutaneous aspiration culture and sensitivity tests.[
31] Seven out of 10 (70%) patients improved within 1–3 weeks with the new antibiotic coverage. It can therefore be concluded that aggressive interventional drainage can be of diagnostic as well as therapeutic value in managing lung abscesses.[
31–
34]
In summary, the overall success rate of PTD can reach 84% with a complication rate of 16% and associated mortality of 4% (which is much lower than that associated with surgery). This supports the efficacy and safety of PTD in the treatment of pyogenic lung abscesses.