• Journal of Korean Neurosurgical Society
• /
• v.52 no.5
• /
• pp.501-504
• /
• 2012

Objective : To report our surgical experience using in situ end-to-side bypass for giant serpentine distal anterior cerebral artery aneurysm, unsuitable for microsurgical clipping. Methods : A 49-year-old woman presented with headache and intermittent loss of consciousness. The brain computed tomography scan revealed a partially calcified mass in the interhemispheric fissure. On cerebral angiography, that was giant ($30{\times}18mm$ sized), serpentine aneurysm originating from the A2 to A3 segment of the distal anterior cerebral artery (DACA). The aneurysm was trapped with clips, and the right A3 segment to left A3 segment of DACA, end-to-side in situ bypass was performed. Surgical result was favorable, with no newly developed ischemic event in the acute recovery period. Postoperative angiography showed total occlusion of the aneurysm and good patency, with preserved distal flow. Conclusion : Giant fusiform aneurysms of the DACA are extremely rare and can be particularly challenging to treat. End-to-side A3 : A3 bypass with aneurysm trapping could be a treatment modality for these locations.

• Journal of Chest Surgery
• /
• v.26 no.12
• /
• pp.950-954
• /
• 1993

Two patients with chronic Budd-Chiari syndrome resulting from segmental obstruction of the inferior vena cava underwent operation. There were 1 man and 1 woman. The obstructed segment was directly visualized by a transthoracic, transdiaphragmatic, retroperitoneal approach. In these two cases, severe segmental obstruction of the inferior vena cava was observed just above the right hepatic vein. These patients underwent successful retrohepatic cavoatrial bypass with a polytetrafloroethylene [PTFE] graft [ 16mm plain and 16mm ringed graft ]. There were no operative mortality and postoperative complication. These patients have been followed up for 6months and 36months without evidence of re-obstruction. When there is a severe stricture of the IVC with hepatic veins draining freely into the obstructed segment of the IVC, a dorsal cavoatrial bypass with a PTFE graft, preferably ringed, is the method of choice.

• Journal of Korean Neurosurgical Society
• /
• v.58 no.5
• /
• pp.467-470
• /
• 2015

A 74-year-old patient was diagnosed with a subarachnoid hemorrhage suspected from a dissecting aneurysm located at the lateral medullary segment of the posterior inferior cerebellar artery (PICA). Because perforators to the medulla arose both proximal and distal to the dissecting segment, revascularization for distal flow was essential. However, several previously reported methods for anastomosis, such as an occipital artery-PICA bypass or resection with PICA end-to-end anastomosis could not be used. Ultimately, we performed an in situ side-to-side anastomosis of the proximal loop of the PICA with distal caudal loops within a single artery, as a "closing omega," followed by trapping of the dissected segment. The aneurysm was obliterated successfully, with intact patency of the revascularized PICA.

• Journal of Chest Surgery
• /
• v.17 no.4
• /
• pp.691-697
• /
• 1984

After the real birth of vascular surgery occurred with the introduction of the first practical arterial prosthesis about 50 years ago, a variety of potential vascular graft had been tested and rejected. Polytetrafluoroethylene [Teflon, PTFE] was first used as a vascular prosthesis in 1957. Thereafter this pros-thesis was first used clinically in 1972 and has subsequently been widely applied as a small and medium sized vessel replacement because it is easy to use and readily available. There are numerous reports of good results about Polytetrafluoroethylene graft. We experienced the three cases of arterial bypass graft using polytetrafluoroethylene vascular pros-thesis. First, 21 years old female patient had suffered from Takayasus disease which affected the left subclavian artery and right subclavian-left axillary extra anatomical bypass graft as done. Second, 64 years old male patient had suffered from Leriche syndrome for 12 years and the left axillofemoral and femorofemoral extra anatomical bypass graft was done. Third, 34 years old male patient had suffered from recurrent Buergers disease which affected the left popliteal artery and the isolated popliteal artery segment bypass graft was done. Relatively satisfactory result was obtained in early post-operative period in all three cases.

• Journal of Chest Surgery
• /
• v.4 no.1
• /
• pp.35-42
• /
• 1971

This is a report on four cases of bypass for esophageal stricture due to gastro-esophageal carcinoma in the Department of Thoracic Surgery, Chonnam University Hospital. Bypass was performed intrathoracal esophago-jejunostomy by a segment of jejunum. Three patients received end to end anastomosis and the other one side to end esophagojejunostomy. Postoperative results were as follow; There was no swallowing disturbance with regular diet and the patients appear to be more comfortable by bypass than gastrostomy or jejunostomy. Postoperative condition of all the patients was satisfactory because other organs were intact. However, two patients expired in 12 months and 6 months after operation by wide metastasis and the other 2 cases are living now with regular diet in 4 months and 2 months after operation.

• Journal of Mechanical Science and Technology
• /
• v.15 no.9
• /
• pp.1302-1310
• /
• 2001

This paper introduces modeling and simulation results for pipeline inspection gauge (PIG) with bypass flow control in natural gas pipeline. The dynamic behaviour of the PIG depends on the different pressure across its body and the bypass flow through it. The system dynamics includes: dynamics of driving gas flow behind the PIG, dynamics of expelled gas in front of the PIG, dynamics of bypass flow, and dynamics of the PIG. The bypass flow across the PIG is treated as incompressible flow with the assumption of its Mach number smaller than 0.45. The governing nonlinear hyperbolic partial differential equations for unsteady gas flows are solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used for solving the steady flow equations to get initial flow values and the dynamic equation of the PIG. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. Simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of the PIG with bypass flow under given operational conditions of pipeline.

• Journal of Chest Surgery
• /
• v.15 no.4
• /
• pp.409-413
• /
• 1982

The incidence of syphilitic aortic aneurysm was decreased now a day. The predilection site of cardiovascular syphilis is the thoracic aorta, especially ascending portion. The form of syphilitic aneurysm is characterized by saccular or fusiform. We have experienced 58 year old female complained of intermittent left chest pain for these 2 years. Saccular aneurysm of 7 cm in diameter at the descending thoracic aorta just distal to the left subclavian artery was confirmed with aortogram, and etiologic lesion was suspected as syphilis by her strong positive finding of serum VDRL test. Excision of the aneurysm was done under temporary bypass with heparinized 10mm silicone bypass cannula, and 23 mm Dacron aortic prosthetic graft in 10 cm segment was replaced, and excised aortic segment was confirmed as syphilitic aneurysm on light microscopic examination. Postoperative hospital course was uneventful, and discharged 3 weeks after operation in good normotensive condition. The patient died of CVA 3 months after discharge at home.

• Journal of Korean Neurosurgical Society
• /
• v.46 no.1
• /
• pp.68-70
• /
• 2009

A case of large aneurysm arising from the distal end of an azygous A2 segment is presented. Multiple clip application inadvertently tore the aneurysmal neck, resulting in near avulsion of a right pericallosal artery origin. After an unsuccessful attempt to repair the avulsion, it was treated by occlusion of the origin of the pericallosal artery and an A4-A4 anterior cerebral artery in situ bypass without neurological deficits. The surgical technique and previous reports onside-to-side in situ bypass are discussed.

• Journal of Chest Surgery
• /
• v.27 no.4
• /
• pp.324-327
• /
• 1994

Resection and reconstruction of distal trachea or carina have posed tremendous technical challenges for surgeons. Successful outcome depends on thorough preoperative evaluation, careful anesthetic management,strict attention of surgical technique and postoperative care. We report a successful case of revision of tracheal stenosis using femoro-femoral bypass on a 13~year-old boy. The patient complained severe dyspnea about I month following right sleeve pneumonectomy. Preoperative CT scan and intraoperative bronchoscopy showed pin-point tracheal stenosis at a tracheo-bronchial anastomosis site about 1.2cm in length.At operation the lesion was severely adhesed and the lumen was nearly obstructed. The stenotic segment was resected and direct end-to-end anastomosis was done under femoro-femoral bypass for adequate oxygenation. The patient was discharged at postop. 16 days without specific complications and has continued to do well.

• Proceedings of the KSME Conference
• /
• 2001.06b
• /
• pp.241-246
• /
• 2001

This paper introduces modeling and solution for the dynamics of pipeline inspection gauge (PIG) flow in natural gas pipeline. Without of bypass flow, the dynamic behavior of the PIG depends on the different pressure between the rear and nose parts, which is generated by injected gas flow behind the tail of the PIG and expelled gas flow in front of its nose. With bypass flow, the PIG dynamics also depends on the amount of bypass flow across its body. The mathematical model are derived for unsteady compressible flow of the PIG driving and expelled gas, and for dynamics of the PIG. The bypass flow is assumed to be incompressible with the condition of its Mach number smaller than 0.45. The method of characteristic (MOC) and the Runge-Kutta method are used to solve the system governing equations. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. The simulation results show that the derived mathematical model and the proposed solution are effective for estimation the dynamics of the PIG with and without bypass flow under given operational condition.