Oklu, Rahmi

Abstract Ruptured wide‐neck aneurysms (WNAs), especially in a setting of coagulopathy, are associated with significant morbidity and mortality. It is shown that by trapping a sub‐millimeter clinical catheter inside the aneurysm sac using a flow diverter stent (FDS), instant hemostasis can be achieved by filling the aneurysm sac using a novel biomaterial, rescuing catastrophic bleeding in large‐animal models. Multiple formulations of a biomaterial comprising gelatin, nanoclay (NC), and iohexol are developed, optimized, and extensively tested in vitro to select the lead candidate for further testing in vivo in murine, porcine, and canine models of WNAs, including in a subset with aneurysm rupture. The catheter‐injectable and X‐ray visible versions of the gel embolic agent (GEA) with the optimized mechanical properties outperform control groups, including a subset that receive a clinically used liquid embolic (Onyx, Medtronic), with and without aneurysm rupture. A combinatorial approach to ruptured WNAs with GEA and FDS may change the standard of medical practice and save lives.

AbstractSaccular aneurysms (SAs) are focal outpouchings from the lateral wall of an artery. Depending on their morphology and location, minimally invasive treatment options include coil embolization, flow diverter stents, stent‐assisted coiling, and liquid embolics. Many drawbacks are associated with these treatment options including recanalization, delayed healing, rebleeding, malpositioning of the embolic or stent, stent stenosis, and even rupture of the SA. To overcome these drawbacks, a nanoclay‐based shear‐thinning hydrogel (STH) is developed for the endovascular treatment of SAs. Extensive in vitro testing is performed to optimize STH performance, visualization, injectability, and endothelialization in cell culture. Femoral artery saccular aneurysm models in rats and in pigs are created to test stability, efficacy, immune response, endothelialization, and biocompatibility of STH in both ruptured and unruptured SA. Fluoroscopy and computed tomography imaging consistently confirmed SA occlusion without recanalization, migration, or nontarget embolization; STH is also shown to outperform coil embolization of porcine aneurysms. In pigs with catastrophic bleeding due to SA rupture, STH is able to achieve instant hemostasis rescuing the pigs in long‐term survival experiments. STH is a promising semisolid iodinated embolic agent that can change the standard of medical practice and potentially save lives.

Tumors of the lung, including primary cancer and metastases, are notoriously common and difficult to treat. Although surgical resection of lung lesions is often indicated, many conditions disqualify patients from being surgical candidates. Percutaneous image-guided lung ablation is a relatively new set of techniques that offers a promising treatment option for a variety of lung tumors. Although there have been no clinical trials to definitively compare its efficacy to those of traditional treatments, lung ablation is widely practiced and generally accepted to be safe and effective. Especially encouraging results have recently emerged for cryoablation, one of the newer ablative techniques. This article reviews the indications, techniques, contraindications, and complications of percutaneous image-guided ablation of lung tumors with special attention to cryoablation and its recent developments in protocol optimization.

Lower urinary tract symptoms (LUTS) due to benign prostatic hypertrophy (BPH) are a very common problem in men ranging from mild urinary symptoms to recurrent urinary tract infections or renal failure. Numerous treatment options are available ranging from conservative medical therapies to more invasive surgical options. Prostate artery embolization (PAE) has emerged as a novel treatment option for this common problem with clinical efficacy comparable to the current surgical gold standard, transurethral resection of the prostate (TURP). PAE offers fewer complications and side effects without a need for general anesthesia or hospitalization. This review discusses the indications for prostate artery embolization in addition to LUTS, patient evaluation in patients with LUTS, PAE technique and clinical results, with an emphasis on efficacy and safety.

Regenerative medicine is an emerging field that centers on the restoration and regeneration of functional components of damaged tissue. Tissue engineering is an application of regenerative medicine and seeks to create functional tissue components and whole organs. Using 3D printing technologies, native tissue mimics can be created utilizing biomaterials and living cells. Recently, regenerative medicine has begun to employ 3D bioprinting methods to create highly specialized tissue models to improve upon conventional tissue engineering methods. Here, we review the use of 3D bioprinting in the advancement of tissue engineering by describing the process of 3D bioprinting and its advantages over other tissue engineering methods. Materials and techniques in bioprinting are also reviewed, in addition to future clinical applications, challenges, and future directions of the field.

AbstractEmbolization is a catheter‐based minimally invasive procedure that deliberately occludes diseased blood vessels for treatment purposes. A novel silk‐based embolic material (SEM) that is developed and optimized to provide tandem integration of both embolization and the delivery of therapeutics is reported. Natural silk is processed into fibroin proteins of varying lengths and is combined with charged nanoclay particles to allow visibility and injectability using clinical catheters as small as 600 μm in diameter at lengths >100 cm. SEMs loaded with fluorochrome labeled bovine albumin and Nivolumab, which is among the most used immunotherapy drugs worldwide, demonstrate a sustained release profile in vitro over 28 days. In a porcine renal survival model, SEMs with labeled albumin and Nivolumab successfully embolize porcine arteries without recanalization and lead to the delivery of both albumin and Nivolumab into the interstitial space of the renal cortex. Mechanistically, it is shown that tissue delivery is most optimal when the internal elastic membrane of the embolized artery is disrupted. SEM is a potential next‐generation multifunctional embolic agent that can achieve embolization and deliver a wide range of therapeutics to treat vascular diseases including tumors.

AbstractHepatocellular carcinoma (HCC) is the fastest-growing cancer worldwide, causing significant morbidity and mortality. Surgical resection, ablation, or transplantation is the best treatment option for patients with HCC. However, only about one-fifth of patients are suitable for such primary curative treatments due to underlying liver disease or rapid extension of the tumor. Image-guided locoregional therapies may prove an important alternative in this scenario, particularly transarterial radioembolization (TARE) with yttrium-90 (Y-90). Based on many studies, TARE can be considered a curative treatment option for patients with early-stage HCC, a bridge to transplantation, and a method for downstaging tumors to give patients with unresectable HCC a chance to potentially receive a curative treatment. TARE can be also combined with other treatment modalities to provide a better quality of life in patients when compared with systemic therapy in patients with unresectable HCC. Here, we discuss the use of TARE in the approach to HCC patients who are in early, intermediate, or advanced stages.

Preoperative planning is critical for success in the surgical suite. Current techniques for surgical planning are limited; clinicians often rely on prior experience and medical imaging to guide the decision-making process. Furthermore, two-dimensional (2D) presentations of anatomical structures may not accurately portray their three-dimensional (3D) complexity, often leaving physicians ill-equipped for the procedure. Although 3D postprocessed images are an improvement on traditional 2D image sets, they are often inadequate for surgical simulation. Medical 3D printing is a rapidly expanding field and could provide an innovative solution to current constraints of preoperative planning. As 3D printing becomes more prevalent in medical settings, it is important that clinicians develop an understanding of the technologies, as well as its uses. Here, we review the fundamentals of 3D printing and key aspects of its workflow. The many applications of 3D printing for preoperative planning are discussed, along with their challenges.