Seong Wook Hong

Antiallodynic effects of vitamin C and vitamin E in chronic post-ischemia pain rat model

Background Recent research has shown that reactive oxygen species (ROS) play a significant role in the development and persistence of neuropathic pain through central sensitization via N-methyl-D-aspartate (NMDA) receptor activation. In the present study, we examined whether the intraperitoneal administration of vitamins C and E alone or together could alleviate mechanical allodynia in a chronic post-ischemia pain (CPIP) rat model. Methods Vitamins C and E were administered intraperitoneally to 48 male Sprague Dawley rats once per day for 3 days before hindpaw ischemia-reperfusion (I/R) injury was induced. On the third day, the CPIP rat model was produced by inducing ischemia in the left hindpaw by applying an O-ring for 3 h, followed by reperfusion. Three days after reperfusion, hindpaw mechanical allodynia was assessed by measuring the withdrawal response to von Frey filament stimulation. The rats were sacrificed immediately after behavioral testing to determine the phosphorylated NMDA receptor subunit 1 (pNR1) and extracellular-signal-regulated kinases (pERK) levels in the spinal cord. Results When the antioxidant vitamins C and E were administered intraperitoneally to CPIP rats, I/R injury-induced mechanical allodynia was attenuated, and pNR1 and pERK levels were decreased in the rat spinal cord. Additionally, the co-administration of both vitamins had an increased antiallodynic effect. Conclusions The reduced phosphorylated NR1 and ERK levels indicate that vitamins C and E inhibit the modulation of spinal cord neuropathic pain processing. Co-administration of vitamins C and E had a greater antiallodynic effect.

Effects of early vital capacity maneuver on respiratory variables during multivessel off-pump coronary artery bypass graft surgery

Objectives:Despite avoiding cardiopulmonary bypass, similar degrees of pulmonary impairment compared with on-pump coronary artery bypass surgery have been demonstrated in patients undergoing off-pump coronary artery bypass graft surgery (OPCAB) compared with on-pump coronary artery bypass surgery. To investigate the effects of an early vital capacity maneuver (VCM) on intrapulmonary shunt (Qs/Qt), oxygenation, and pulmonary outcome in OPCAB. Design:Prospective, randomized, controlled, double-blind clinical trial. Setting:Cardiothoracic operating room and intensive care unit (ICU) of a university hospital. Patients:Fifty patients scheduled for OPCAB were randomized to treatment with VCM or none. Interventions:After sternotomy, VCM was performed by inflating the lungs to 40 cm H2O and holding this pressure for 10 seconds. Measurements and Main Results:Qs/Qt, Pao2/Fio2 (P/F) ratio, and dynamic and static pulmonary compliances were measured before induction of anesthesia (T0), 15 minutes after tracheal intubation (T1), during Y-graft construction (T2), 15 minutes after completion of grafting (T3), 15 minutes after sternal closure (T4), and 3 hours after arrival at the ICU (T5). Qs/Qt was lower and P/F ratio was higher in the VCM group at T2 through T5. Pulmonary compliances were also higher in the VCM group at T4 and T5. Patients in the VCM group were extubated earlier. Conclusions:The beneficial effects of an early VCM on Qs/Qt persisted into the period of ICU care, with an improvement in P/F ratio and preserved pulmonary compliances, leading to a shorter time to extubation.

Abnormal Origin of the Left Subclavian Artery from the Left Pulmonary Artery in a Patient with Double Outlet Right Ventricle

Anomalous aortic origin of the left subclavian artery (LSCA) from the left pulmonary artery (LPA) is a rare congenital cardiac malformation. We describe a case of LSCA from the LPA via ductus arteriosus in association with a double-outlet right ventricle, which never has been reported previously in Korea.

Target-controlled infusion of remifentanil for conscious sedation during spinal anesthesia

Background The aim of this study was to define the optimal target concentration of remifentanil which effectively achieves conscious sedation without significant vital sign changes and side effects during spinal anesthesia. Methods Sixty patients underwent spinal anesthesia with 0.5% hyperbaric bupivacaine (8-16 mg), and were infused with a target controlled infusion (TCI) of remifentanil at 1.0 ng/ml (group R10, n = 15), 2.0 ng/ml (group R20, n = 15), 3.0 ng/ml (group R30, n = 15), and 3.5 ng/ml (group R35, n = 15). Observers assessment of alertness/sedation (OAA/S) scale, the bispectral index (BIS), anxiety levels and infusion rate of remifentanil were monitored during the operation. Results OAA/S scale was significantly lower in groups R30 (3.96) and R35 (3.34) than groups R10 (4.31) and R20 (4.26). Incidence of intraoperative respiratory depression events, post operative nausea and vomiting were significantly higher in group R35 than the other groups. There were no significant differences in BIS, anxiety level and incidences of recall of the operative procedure among the groups. Conclusions We conclude that the TCI of remifentanil at 3.0 ng/ml produces an effective sedation and anti-anxiety effects without significant side effects during spinal anesthesia.

Effect of arterial oxygen tension during reperfusion on myocardial recovery in patients undergoing valvular heart surgery

Background Valvular heart surgery (VHS) utilizing cardiopulmonary bypass (CPB) is inevitably associated with ischemic-reperfusion injury, which is known to depend on oxygen tension during reperfusion. The aim of this study was to evaluate the effect of arterial oxygen tension during reperfusion on myocardial recovery in patients undergoing VHS. Methods Fifty-six patients undergoing isolated VHS were randomly exposed to an oxygen fraction of 0.7 (hyperoxic group, n = 28) or 0.5 (normoxic group, n = 28) during reperfusion. All patients received an oxygen fraction of 0.7 during CPB. In the normoxic group, the oxygen fraction was lowered to 0.5 from the last warm cardioplegia administration to 1 minute after aortic unclamping, and was then raised back to 0.7. Hemodynamic data were measured after induction of anesthesia, weaning from CPB, and sternum closure. The frequency of cardiotonic medications used during and after weaning from CPB, and the short-term outcomes during the hospital stay were also assessed. Results The frequency of vasopressin and milrinone use during weaning from CPB, but not norepinephrine, was significantly less in the normoxic group. The post-operative cardiac enzyme levels and short-term outcomes were not different between the groups. Conclusions Normoxic reperfusion from the last cardioplegia administration to 1 minute after aortic unclamping in patients undergoing VHS resulted in significantly less frequent use of vasopressin and inotropics during weaning from CPB than hyperoxic reperfusion, although it did not affect the post-operative myocardial enzyme release or short-term prognosis.

Computed tomography-guided cervical selective transforaminal epidural block for a patient with bilateral anatomical variations of vertebral artery -a case report-.

A 56-year-old woman complained of radiating pain to the left arm. She was diagnosed with left-sided foraminal stenosis at the C5-6 level. The neurosurgeon requested a left C6 cervical selective transforaminal epidural block (CSTE). Cervical MRI showed a left-sided large tortuous vertebral artery (VA) at the C5-6 level. Before performing CSTE, a CT angiogram was carried out and showed bilateral tortuous VAs. To minimize adverse events, CSTE was performed with non-particulated steroids and under CT guidance. Following the procedure, the patients symptoms were relieved completely. Although complication rates of CSTE are generally low, if it occurs, disastrous situation could be. Additionally, if the patient has anatomical variations, the possibility of a complication occurring is greatly increased. It is therefore important to determine whether the patient has any anatomical variations of the VA before performing procedures such as CSTE, and to ensure that needle placement is correct during the procedure and an appropriate drug, such as a non-particulated steroid, is selected.

Treatment of radiation-induced cystitis and vulvodynia via a ganglion impar block using a lateral approach under computed tomography guidance: a case report

Adjuvant radiation therapy (RT) after colorectal cancer surgery can prevent local recurrence, but has several side effects. Precise injection of drugs into the affected areas is complicated by radiation-induced fibrosis of soft or connective tissue. A 48-year-old woman experienced severe intractable perineal pain, dysuria, urinary urgency, and frequent urination after rectal cancer surgery and adjuvant RT, and was diagnosed with radiation-induced cystitis and vulvodynia. Her symptoms persisted despite two fluoroscopy-guided ganglion impar blocks. Fluoroscopy revealed atypical needle tip positioning and radiolucent dye distribution, presumably due to radiation-induced fibrosis in the target region. We performed two computed tomography (CT)-guided ganglion impar blocks by using a lateral approach, which allowed more accurate po-sitioning of the needle tip. Her pain visual analog score decreased from 9 to 3, and she recently resumed sexual intimacy. CT guidance is a viable alternative to fluoroscopy guidance when performing ganglion impar blocks in fibrotic areas.

Non-Anastomotic Rupture of a Woven Dacron Graft in the Descending Thoracic Aorta Treated with Endovascular Stent Grafting

The intrinsic structural failure of a Dacron graft resulting from the loss of structural integrity of the graft fabric can cause late graft complications. Late non-anastomotic rupture has traditionally been treated surgically via open thoracotomy. We report a case of the successful use of thoracic endovascular repair to treat a Dacron graft rupture in the descending aorta. The rupture occurred 20 years after the graft had been placed. Two stent grafts were placed at the proximal portion of the surgical graft, covering almost its entire length.

Treatment of Large Arteriovenous Malformation in Right Lower Limb

A 10-year-old boy with arteriovenous malformation (AVM) of the right lower limb was scheduled for an amputation of the affected limb. Limb amputation was necessary because of the ineffectiveness of previous sclerotherapy and the rapid progression of AVM causing pain and heart failure. Right hip disarticulation was considered the best option to improve his quality of life. To prevent congestive heart failure and uncontrollable hemorrhage during surgery, the disarticulation was done under a partial cardiopulmonary bypass. The patient underwent surgery successfully without complications.

Extra cardiac tumor misdiagnosed as a left atrial myxoma

Cardiac tumors, which are characterized by very a low prevalence of approximately 0.02% based on pooled data, can cause considerable morbidity and mortality due to cardiac conduction abnormalities, embolization of the tumor fragment or associated thrombus, or intra-cardiac obstructions [1]. Primary cardiac tumors are usually benign in adults, with only 20-25% cases being reported as malignant, and myxoma is the most common cardiac neoplasm, accounting for nearly 50% of cases of cardiac tumors. Myxomas most commonly originate in the left atrium; however, sarcomas may also present as a left atrial (LA) mass, and may be mistaken for a myxoma, preoperatively. For myxomas, surgical resection is adopted as a curative treatment, and transesophageal echocardiography (TEE) is currently the most powerful cardiovascular monitoring technique available in the perioperative medicine setting; it plays a vital role in the assessment of cardiac surgical plans and in anesthetic management [2]. Herein, we report the case of a patient with a malignant extra cardiac tumor that was misdiagnosed as an LA myxoma; in this case, intra-operative TEE played a pivotal role in facilitating the completion of the resection during cardiac surgery. A 3 cm mass or thrombus-like lesion within the LA cavity was detected incidentally, upon chest computed tomography (CT) in a 51-year-old woman (Fig. 1A). A subsequent transthoracic echocardiographic examination (TTE) also revealed the presence of an echogenic mass, with characteristic features of a myxoma in the left atrial appendage (LAA), and concomitant mild mitral valve regurgitation, but normal ejection fraction (59%). An operation, involving median sternotomy under the general anesthesia, including minimally invasive techniques and a cardiopulmonary bypass (CPB), was performed with the aim of resecting the presumed LA myxoma. The anesthetic management proceeded uneventfully, with 0.5% sevoflurane, and continuous infusion of fentanyl with rocuronium was administered. Prior to CPB initiation, the TEE examinations detected a mobile mass between the LAA and left pulmonary vein, which confirmed the echocardiographic findings of the preoperative TTE examinations (Fig. 1B). The surgery aimed to remove the mass, with concomitant mitral valvuloplasty; the excised mass (2 × 2 cm in size) was gelatinous and mobile, and was attached to the wall between the LAA and left upper pulmonary vein. However, after rewarming and repairing the left atriotomy, the post-CPB TEE examinations revealed that the tumor was still present within the LA cavity (Fig. 1C). After discussion with the surgeons, the mass was inspected once more via a left atriotomy; however, visual inspection did not indicate any tumor within the cavity. Conversely, the TEE revealed that the mass was still located in the LA. It was concluded that the mass was of an extra-cardiac origin; subsequently, re-weaning from the CPB was performed uneventfully. The patient awoke 4 hours after arriving at the intensive care unit, with no neurological deficits; she was discharged uneventfully on POD 15. A postoperative chest CT only revealed mural thrombi at the anterior aspect of the LA; however, the LAA was not observed. Conversely, the postoperative TTE did not reveal any mass in the LA cavity, and an ejection fraction of 46% was recorded. Histopathological analysis indicated an undifferentiated epithelioid sarcoma, which appeared to be a malignant fibrous histiocytoma (MFH) upon microscopy. The metastatic workup was negative, and the patient subsequently underwent chemotherapy. Fig. 1 Computerized tomography of the chest revealed a cardiac mass (T) at the anterior portion of the left atrium (A). Transesophageal echocardiographic, midesophageal two-chamber view prior to the initiation of cardiopulmonary bypass. The mass (★) ... Preoperatively, most cardiac masses are considered to be benign, and thus, a diagnosis of sarcoma is often made during or after surgery, based on the tumor characteristics or pathology. Furthermore, almost all malignant tumors occur preferentially on the right side of the heart; however, we report a case of a primary cardiac sarcoma in the left atrium, mixed with cardiac myxoma. Some echocardiographic characteristics may help differentiate an MFH from an atrial myxoma; of these, one of the most common features is the site of its origin. Atrial myxomas are usually attached to the fossa ovalis, but may arise from the mitral or tricuspid valves, or even the right atrium [3]. Conversely, MFHs commonly originate near the pulmonary veins or the LAA. Moreover, the attachment of an MFH to the endocardium is typically broad-based, thus differentiating them from typical atrial myxomas, which are commonly attached via a stalk or a pedicle [4]. In the present case, upon TEE examination prior to CPB, the mass was observed in the LAA, extending from the left upper pulmonary vein. A more observant diagnosis, based on the TEE findings at this point, might have reduced the unnecessary expenses. In this case, the mass in the LA cavity that was identified by TEE examination after CPB was considered to be a primary cardiac tumor originating from the epicardium. Therefore, the mass that was removed was only a small portion of the tumor that invaded the LAA. After rewarming, another search was conducted for the remnant mass through a left atriotomy, however, no tumor was found within the cavity. This might also be explained by the extra-cardiac origin nature of the mass. Irrespective of the cause or location of the tumor, a comprehensive TEE examination during cardiac surgery remains the best method for detecting intra-cardiac tumors, and can provide the surgeon with the information needed to finalize the surgical plan and to evaluate the successful excision of the cardiac mass and achieve minimal damage to adjacent structures during excision [5]. This case confirms that tumors of extra-cardiac origin may also occur, and hence, this possibility should be considered when the location or shape of the mass lesion is unusual on pre- CPB TEE examinations, or when remnant mass-like lesions are noted on post-CPB TEE examinations during LA myxoma surgeries.