Empyema

All patients between 2007 and 2022 undergoing esophageal resections and reconstruction with a gastric conduit that developed an anastomotic leakage in the postoperative course were included in this study. An anastomotic leakage had to be verified by (CT-) contrast swallow, upper endoscopy (EGD), or by an intraoperatively observed dehiscence of the esophagogastric anastomosis. The data were collected retrospectively from medical files including ICU reports, OP notes, and discharge letters as well as from radiographic and endoscopic reports. The information was gathered from the University Hospital Regensburg’s institutional archive and database (SAP Version 7.50).
Demographical data such as age, gender, and body weight as well as the medical history were recorded. Data regarding neoadjuvant treatment, surgery, and complications in the postoperative course including the management of the anastomotic leakage were obtained for statistical evaluation. Patients were included in the eVAC cohort, if at least one complete cycle of eVAC therapy (3–4 days) was performed. Other treatment modalities such as placement of fully covered self-expanding metal stents (fcSEMS), external drainage tubes, or initial watch-and-wait therapy could be part of the overall treatment concept in the eVAC cohort, given, that eVAC therapy was applied for at least one full cycle. A surgical revision for drainage and lavage of the thoracic cavity was defined as complementary treatment in the eVAC and non-eVAC group, given, that an empyema or intrathoracic abscess/fluid collection was not amenable for interventional/endoscopic drainage. eVAC was performed using the Eso-SPONGE device (B. Braun SE; Melsungen, Germany) placed endoscopically in the thoracic cavity or intraluminal. A negative pressure gradient of − 125 mmHg was applied on the eVAC using V.A.C. ULTA system (3 M Deutschland GmbH). fcSEMS from TaeWoong Medical (Niti-S Esophageal Stent, Taewoong Medical, Gyeonggi-do, South Korea) and M.I. Tech, (Hanarostent, M.I. Tech, Seoul, South Korea) were used (diameter 20–22 mm, length 110–140 mm). The decision to use additional treatment modalities in the eVAC group, e.g., fcSEMS, was an individual decision in each case, based on the clinical appearance of the anastomotic leakage as well as on its development over the course of time and the experience of the treating surgeon/endoscopist.
A failure of treatment, defined by either formation of a cervical esophagostomy or death (30- and 90-day mortality) was the primary outcome parameter. Furthermore, as secondary outcomes, the cumulative hospital- and ICU-stay were recorded.

We limited the database searches to studies published from 2003 onwards, as the first PCV was introduced globally in 2000 and one of our inclusion criteria was its use at least for three years or more post-introduction. We further applied limits to exclude randomized controlled trials, case-control studies, case reports, and case series studies, as the impact of a vaccination programs is evaluated with post-licensure observational studies [7 ,8 ]. We also restricted the searches to English language publications. The inclusion criteria for this review were: post-licensure observational studies reporting on incidence rates, rate ratios, or percent difference and comparing the outcomes of hospitalised pneumonia, all-cause empyema, all-cause mortality, or pneumonia mortality in any time period before to at least three years after the introduction of either PCV10 or PCV13 into the NIP, allowing more time for indirect and total effects to occur [9 (link)]. Full details of the inclusion and exclusion criteria are available in the Online Supplementary Document. We include studies in settings where PCV10 or PCV13 were the first PCV to be introduced into the NIP or where PCV7 was first introduced and subsequently replaced by either PCV10 or PCV13. We excluded studies if the population did not include children 0-9 years, if less than 50% of the catchment population received PCV in the post-PCV period, or if they compared only the PCV7 period to PCV10 or PCV13 period (Table S1 in the Online Supplementary Document). Two reviewers independently extracted the data and any disagreements were resolved through discussion.
We used the Effective Public Health Practice Project (EPHPP) quality assessment tool for quantitative studies [10 ] to assess the level of risk of bias for each study, as well as to evaluate their internal validity of each study was evaluated considering eight methodological – selection bias of study participants, study design, confounders, blinding, data collection methods, withdrawals of study participants, intervention integrity, and analysis. The protocol is available upon request from the authors.
We did not conduct meta-analyses due to the heterogeneity between studies and case definitions of pneumonia outcomes (case definitions are shown in Table S2 in the Online Supplementary Document). Study results were stratified by age group, world bank country income status, time since PCV introduction, and PCV valency.