Data_Sheet_1_The Role of Hyperbaric Oxygen Therapy in Pneumatosis Cystoides Intestinalis—A Scoping Review.PDF

Pneumatosis cystoides intestinalis (PCI) is characterized by gas-filled cysts within gastrointestinal tract wall from esophagus to rectum, with preferential involvement of large and small intestine. PCI is rare with an estimated incidence of 0.03 to 0–2% in general population. PCI can be distinguished into idiopathic (15%) or secondary (85%) and the clinical picture ranges from completely asymptomatic to life-threatening intraabdominal complications. Although etiology of PCI appears to be multifactorial, the exact pathophysiology is poorly understood and two main theories have been proposed (mechanical and bacterial). Over the last decades, an enormous therapeutic armamentarium was considered in PCI's management, including hyperbaric oxygen therapy (HBOT). Treatment comprises conservative treatment in mild cases to surgery in highly symptomatic and complicated PCI. In the late 70s, HBOT started to be used in selected cases of PCI not responding to conservative measures. Since then, several case reports, case series, and reviews have been published in the literature with variable outcomes. The overall response rate and complete response were 92.1% (n = 82/89) and 65.2% (n = 58/89), respectively, with a median follow-up of 7 months. Furthermore, HBOT is extremely safe, with few reported complications in the literature when used for PCI. Nevertheless, a randomized, controlled, and double-blind clinical trial is unlikely to occur given the rarity of PCI, logistical issues of HBOT, and methodological considerations related to adequate blinding with a sham-controlled group. HBOT in combination with personalized diet and antibiotics may be beneficial for moderate to severe PCI in patients with no indication for emergency exploratory laparotomy. The purpose of this article is to synthesize the existing data, analyse results of previous studies, identify gaps in knowledge, and discuss PCI' management, including the proposal of an algorithm, with a special focus on HBOT.

肠气囊肿症（Pneumatosis cystoides intestinalis, PCI）以食管至直肠的胃肠道壁内出现含气囊肿为特征，好发于大肠与小肠。PCI属于罕见病，普通人群中的估计发病率为0.03%~0.2%。PCI可分为特发性（占比15%）与继发性（占比85%）两类，其临床表现从完全无症状到危及生命的腹腔并发症不等。尽管PCI的病因看似为多因素，但确切的病理生理机制仍未明确，目前已提出机械学说与细菌学说两种核心假说。近数十年来，PCI的临床治疗手段日趋丰富，其中包括高压氧治疗（hyperbaric oxygen therapy, HBOT）。治疗方案需依据病情严重程度分层选择：轻症患者可采用保守治疗，症状严重且合并并发症的患者则需接受手术干预。20世纪70年代末，高压氧治疗开始被应用于对保守治疗无应答的筛选PCI病例。自此之后，学界已发表多项病例报告、病例系列研究与相关综述，但其治疗结局存在一定异质性。现有数据显示，PCI患者接受高压氧治疗后的总体应答率与完全缓解率分别为92.1%（n=82/89）与65.2%（n=58/89），中位随访时间为7个月。此外，高压氧治疗用于PCI治疗时安全性极佳，文献中仅报道过极少数相关并发症。然而，鉴于PCI的罕见性、高压氧治疗的后勤保障难题，以及假治疗对照组实现充分盲法的方法学限制，开展随机对照双盲临床试验的可能性极低。对于无需急诊剖腹探查术的中重度PCI患者，高压氧治疗联合个性化饮食与抗生素或可带来临床获益。本文旨在整合现有研究数据、分析既往研究结果、明确当前认知空白，并探讨PCI的规范化诊疗方案——包括提出针对性的诊疗流程算法，重点聚焦高压氧治疗的临床应用。