Gas Embolism After Hydrogen Peroxide Use During Spine Surgery: Case Report and Literature Review

Simultaneous gas embolism and pneumocephalus after paravertebral irrigation with hydrogen peroxide: A rare case report

INTRODUCTION

Gas embolism is a rare but fatal clinical emergency. Hydrogen peroxide (H2O2) can cause gas embolism when improperly used in closed cavities or for deep and large wound irrigation.

PRESENTATION OF CASE

A 31-year-old woman was diagnosed with lumbar-3 tuberculosis and paravertebral abscess and underwent emergency spinal surgery in a prone position. After removing the tuberculous pus, 200 mL of H2O2 (3 % v/w) was used to repeatedly irrigate the abscess cavity. Immediately after irrigation, the patient suffered cardiac arrest. During cardiopulmonary resuscitation, transesophageal echocardiography revealed that the right cardiac cavity was filled with a diffuse "Snowflake-Like" gas embolus, and cranial computed tomography showed a multi-point pneumocephalus in the frontal lobes. The patient eventually suffered brain death despite the return of spontaneous circulation after active resuscitation.

DISCUSSION

H2O2 can quickly release abundant oxygen and water upon contact with catalase. Oxygen bubbles enter the vascular lumen and cause mechanical obstruction of the right cardiac circulation. In addition, H2O2 and oxygen bubbles may migrate upwards and enter the intracranial tissue through the epidural space or subdural space, resulting in intracranial pneumatosis. Diagnosis and treatment of gas embolism are extremely difficult. Some suggestions are that H2O2 should not be used in closed cavities or on deep and large wounds due to the potential risk of fatal gas embolism.

CONCLUSION

The fatal complications of gas embolism and pneumocephalus rarely occur simultaneously in one patient, and we aim to highlight this potential risk of intraoperative H2O2 use in spinal surgery.

Endoscopic Ultrasound-Guided Drainage of Pancreatic Fluid Collections: Not All Queries Are Already Solved

Pancreatic fluid collections (PFCs) are well-known complications of acute pancreatitis. The overinfection of these collections leads to a worsening of the prognosis with an increase in the morbidity and mortality rate. The primary strategy for managing infected pancreatic necrosis (IPN) or symptomatic PFCs is a minimally invasive step-up approach, with endosonography-guided (EUS-guided) transmural drainage and debridement as the preferred and less invasive method. Different stents are available to drain PFCs: self-expandable metal stents (SEMSs), double pigtail stents (DPPSs), or lumen-apposing metal stents (LAMSs). In particular, LAMSs are useful when direct endoscopic necrosectomy is needed, as they allow easy access to the necrotic cavity; however, the rate of adverse events is not negligible, and to date, the superiority over DPPSs is still debated. Moreover, the timing for necrosectomy, the drainage technique, and the concurrent medical management are still debated. In this review, we focus attention on indications, timing, techniques, complications, and particularly on aspects that remain under debate concerning the EUS-guided drainage of PFCs.

Percutaneous Chemical and Mechanical Necrosectomy for Walled-Off Pancreatic Necrosis

PURPOSE

To test the hypothesis that percutaneous combined chemical and mechanical necrosectomy using a Malecot anchor drain and an Arrow-Trerotola percutaneous thrombolytic device (PTD) in patients with walled-off pancreatic necrosis (WOPN) is feasible, safe, and effective compared with a control group undergoing mechanical necrosectomy alone.

MATERIALS AND METHODS

In a retrospective analysis, patients with WOPN not amenable to endoscopic-guided cystogastrostomy placement were studied as case and control groups. The patients in the case group underwent percutaneous combined chemical (hydrogen peroxide 3%) and mechanical necrosectomy using a Malecot anchor drain and/or Arrow-Trerotola PTD from December 2020 to April 2022. The controls underwent mechanical necrosectomy alone without chemical necrosectomy. Clinical success was defined as complete resolution of the cavity on follow-up noncontrast computed tomography scans with subsequent drain removal.

RESULTS

Thirteen patients in the case group and 11 patients in the control group underwent percutaneous drain placement followed by percutaneous combined chemical and mechanical necrosectomy (case group) or mechanical necrosectomy only (control group) for WOPN. Drain placement and necrosectomy were technically successful in all patients studied. One patient in the case group developed postprocedural sepsis because of communication between the cavity and the splenic vein. Another patient in the case group developed bleeding from a branch of the pancreaticoduodenal artery on postnecrosectomy day 9, which was successfully embolized by interventional radiology. No pancreaticocutaneous fistula was reported at the 3-month follow-up. The clinical success rates in the case and control groups were 100% and 38.4%, respectively (P = .003).

CONCLUSIONS

Percutaneous combined chemical and mechanical necrosectomy is a feasible, safe, and effective treatment of WOPN.

Direct Endoscopic Necrosectomy: Timing and Technique

Walled-off pancreatic necrosis (WOPN) is one of the local complications of acute pancreatitis (AP). Several interventional techniques have been developed over the last few years. The purpose of this narrative review is to explore such methodologies, with specific focus on endoscopic drainage and direct endoscopic necrosectomy (DEN), through evaluation of their indications and timing for intervention. Findings indicated how, after the introduction of lumen-apposing metal stents (LAMS), DEN is becoming the favorite technique to treat WOPN, especially when large solid debris or infection are present. Additionally, DEN is associated with a lower adverse events rate and hospital stay, and with improved clinical outcome.