This research examines the impact of internationalization on small and medium enterprise (SME) survival, and the direct and moderating effects of technology resources and research and development (R&D) alliances. Our survey examination of 1,612 Korean SMEs reveals that sales internationalization is associated with better survival prospects, suggesting that failure risk does not increase with cross-border sales. In addition, though technology resources provide no direct survival benefits, R&D intensity acts as a moderator in the internationalization-to-survival relationship. R&D alliances, on the other hand, are directly linked with survival but do not show a moderating effect. This supports the liabilities of newness and smallness view that external relationships can help counter survival threats but suggests that the accumulation of technology resources may be more important when firms seek international expansion.

Surgical clip migration and subsequent stone formation in the common bile duct is a rare but well-established complication after laparoscopic cholecystectomy. There are some suggestions about the mechanisms of the migration process, but the details are still unclear. We report here a case in which common bile duct stones were formed around surgical clips, and other clips were found to have penetrated into the common hepatic duct, which we believe were in the process of migration after laparoscopic cholecystectomy. The patient required a laparotomy to retrieve the bile duct stones due to the distal stricture, and another laparotomy was necessary to remove the penetrating clips, which were deeply embedded in the bile duct wall. Although a variety of endoscopic and percutaneous interventional procedures are available in this era of modern medical technology, it is sometimes impractical to apply these procedures in such cases as ours, and exploratory laparotomy is sometimes required to correctly treat the patient. This case shows that the metallic surgical clips can penetrate into the intact bile duct wall through serial maceration, and we believe that careful application of clips may be the only way to prevent their migration after laparoscopic cholecystectomy.

Afferent loop obstruction caused by enterolith formation is rare and cannot be easily treated with endoscopy because of the difficulty associated with the nonsurgical removal of enteroliths. A 74-year-old woman was admitted with fever and acute abdominal pain. Clinical features and imaging studies suggested afferent loop obstruction caused by an enterolith after Roux-en-Y hepaticojejunostomy. Percutaneous transhepatic biliary drainage was initially performed because of severe cholangitis with septic shock. The enterolith was located in the jejunal limb adjacent to the hepaticojejunostomy site. Cholangioscopic lithotripsy was performed through the percutaneous transhepatic route to the enterolith, and the fragments were moved into the efferent loop using scope push and saline flush methods. Here, we describe a case of afferent loop syndrome caused by an enterolith that developed after Roux-en-Y hepaticojejunostomy and was treated with percutaneous transhepatic cholangio-enteroscopic lithotripsy.

Pancreaticoduodenal artery (PDA) aneurysm and celiac artery (CA) stenosis are rare diseases in themselves. Interestingly, however, there are more cases documented in the literature in which these two disease entities occurred together than could be coincidental, and CA stenosis has been suggested as the provocative condition in developing PDA aneurysm. This study is aimed at examining the causal relationship between CA stenosis and PDA aneurysm by simulating the splanchnic circulation with an electric circuit. A patient with multiple PDA aneurysms and collaterals with CA stenosis was treated in our institution using hybrid techniques. The patient’s pre- and postoperative status was simulated using an electric circuit, and the two possible scenarios were tested for compatibility: the stenosis-first scenario vs. the aneurysm-first scenario. The simulation was performed in two ways: using Simulink® software (MATLAB® Release 2018b) and actual circuit construction on a breadboard. The stenosis-first scenario showed that as the CA stenosis progresses, the blood flow through PDA increases, favoring the development of an aneurysm and/or collaterals if the artery was already compromised by a weakening condition. On the other hand, the aneurysm-first scenario also showed that if the aneurysm or collaterals developed first, the aneurysm will steal the blood flow through the CA, causing it to collapse if the artery was already compromised by increased wall tension. Contrary to the common belief, this study showed that in patients suffering from concurrent CA stenosis and PDA aneurysm, either condition could develop first and predispose the development of the other. The simulation of splanchnic blood flow with an electric circuit provides a useful tool for analyzing rare vascular diseases that are difficult to provoke in clinical and animal studies.