Volume 10, Issue 4

Introduction Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is an innovative intraperitoneal drug delivery technique utilizing a nebulizer to aerosolize liquid chemotherapy agents under pressure, distributing them evenly throughout the peritoneal cavity to achieve therapeutic effects. As increasing clinical evidence supports the safety and efficacy of PIPAC as a promising treatment for peritoneal metastasis, optimizing nebulizer technology to enhance treatment outcomes has garnered significant research interest. Content Following initial investigations into the internal structure, mechanical properties, and optimization parameters of the original PIPAC nebulizer, researchers worldwide have focused on refining nebulizer design and exploring innovative applications of aerosolization devices, resulting in the development of several clinically applicable nebulizers with distinct characteristics. Summary This review aims to provide a comprehensive examination of the global advancements in PIPAC nebulizer development, the nebulizer alternative devices, evaluation parameters and methods, as well as future research directions, aiming to inform the development, optimization, and application of novel nebulizers for PIPAC, thereby contributing to the advancement of this promising therapeutic approach. Outlook Current methods for evaluating nebulizer performance are continually being refined, and the integration of nebulizers with other physical modalities holds great promise for further improving PIPAC outcomes.

Objectives In 2020, Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC) reached stage 2b of the IDEAL framework and a prospective international PIPAC database was launched in June 2020 by the International Society for the Study of the Pleura and Peritoneum (ISSPP). The ISSPP PIPAC database consists of six key elements, which are reported in an annual report. The ISSPP Registry Group decided to investigate data completeness within the ISSPP PIPAC Database. Methods Retrospective analysis of data completeness in the six key elements was performed between October 1st and 14th, 2024. This was complemented by an in-depth analysis of missing data in Response Evaluation, Complications, and Follow-up . Results Thirty centers, 950 patients, and 2777 PIPAC procedures were registered in the ISSPP database by October 2024. Sixteen of the 30 centers had included patients. Incomplete data were observed in four of the six key elements. Most centers (7/16) had incomplete data in Complications , followed by Response evaluation (5/16), and Follow-up (2/16). In depth analysis showed that, e.g., for complications, the date and type of the complication was registered in 88 and 89 %, respectively. Incomplete data in Response evaluation occurred mainly in the small group of patients evaluated by nonperitoneal regression grading score (non-PRGS, n=316), where no scoring was provided in 211 patients (72 %). Follow-up data, such as date of death or reasons for stopping PIPAC, were provided for 86 and 85 % of patients. Conclusions Overall data completeness of the ISSPP PIPAC Database was considered satisfactory at the present state, and the ISSPP Registry Group has launched several initiatives to further improve data completeness and quality, to provide solid data sets for future annual reports and other research.

Objectives Complicated pleural infections present significant challenges. Predominant causative microorganisms include the Streptococcus anginosus group (SAG) and Klebsiella pneumoniae (KP). However, limited data are available on the risk factors and outcomes associated with SAG-related pleural infection compared to KP-related pleural infection. Methods This retrospective study was conducted in patients who underwent pleural drainage due to complicated pleural infection at Kyungpook National University Hospital in South Korea between January 2011 and December 2023. Clinical characteristics, drug resistance profiles, and outcomes were compared between patients with SAG-related and KP-related pleural infections. Results A total of 432 patients were assessed. Among them, 161 (37 %) had positive pleural fluid cultures, with SAG (n=68, 42 %) and KP (n=34, 21 %) being the predominant pathogens. Thus, 102 patients with complicated pleural infection caused by SAG or KP were analyzed. SAG cases were associated with higher rates of chronic neurologic disease, lower rates of diabetes mellitus, prolonged symptom duration, elevated white blood cell counts, and positive gram stains on pleural fluid compared to KP cases. There were no significant differences observed between the two groups regarding radiological findings. SAG strains showed resistance rates exceeding 20 % to penicillin, erythromycin, tetracycline, and clindamycin, while remaining largely susceptible to commonly used third-generation cephalosporins, ampicillin, and fluoroquinolones. The in-hospital mortality rates were approximately 10 %, consistent across both groups. Conclusions SAG-related pleural infections showed distinct clinical features, including more frequent chronic neurologic disease, but in-hospital mortality was comparable to that of KP-related infections.

Objectives Peritoneal mesothelioma (PM) shares features with genitourinary (GU) malignancies, including histologic appearance, embryologic origin and genetic predispositions. However, data on their co-occurrence are limited. The study presents a case series of PM patients with associated GU malignancies and explores outcomes following cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). Methods A prospectively maintained CRS-HIPEC database from a tertiary referral center (2011–2024) was reviewed. Demographics, tumor characteristics and outcomes were compared between PM patients with and without GU malignancies (including gynecologic and urologic cancers). Results Among 237 CRS-HIPEC patients, 8/17 patients with PM were found to have another GU malignancy (median age 52.8, 62.5 % male). This included renal cell carcinoma, prostate cancer, ovarian tumors and cervical carcinoma. Most GU malignancies were diagnosed before PM (5/8), two were diagnosed post-CRS-HIPEC, and one synchronously. Three patients reported asbestos exposure; two had BAP1 mutations. Compared to those without GU malignancies, affected patients tended to have higher PCI (19.8 vs. 14.3) and poorer 3-year survival (62.5 vs. 100 %). Conclusions GU malignancy is common among PM patients undergoing CRS-HIPEC and could represent a higher-risk subgroup. These findings raise the hypothesis of a potential association between PM and GU malignancy. Shared origins, oncogenesis of similar cell types, environmental exposures or genetic predispositions may contribute and warrant further investigation.

Objectives Pseudomyxoma peritonei (PMP) is a rare peritoneal malignancy. BromAc ® is a novel therapeutic agent which has been developed to dissolve and facilitate the drainage of mucin as a palliative treatment for PMP; however, its effect is significantly reduced in patients with hard mucin. This study aimed to assess whether combining collagenase or cysteamine with BromAc ® would be more effective in dissolving hard mucin. Methods This preclinical human in vitro study examined the effect of adding collagenase to BromAc ® on hard mucin samples when incubated at 37 °C over 24 h. The effect of cysteamine alone and in combination with collagenase and BromAc ® was also examined as a supplementary arm of this study. Five experiments were conducted with appropriate controls. Human hard mucin samples were sliced into equal fractions using a sterile surgical scalpel, weighed and noted. The leftover solid mucin was weighed at 0, 1, 3, 5, and 24 h post-treatment. Results At 24 h post-treatment, all combinations with collagenase demonstrated almost 100 % dissolution of hard mucin. At 3 and 5 h post-treatment, only BromAc ® with collagenase at 250 μg/mL was found to be superior to BromAc ® alone. Combinations with cysteamine were not found to be effective. Conclusions This study provides promising evidence of the efficacy and synergistic effect of combining BromAc ® with collagenase to dissolve hard mucin. Further preclinical and clinical research should be undertaken to assess its safety and efficacy in the clinical setting.