Jeong-Kye Hwang

Malignancies after kidney transplantation: a 40-year single-center experience in Korea

Cancer is a well‐recognized complication of kidney transplantation (KT), but nearly almost all data have come from Western countries. The aim of this study was to determine the incidence, type, and risk factors of malignancy after KT in Korea. The 1695 patients who underwent KT between 1969 and 2009 were studied retrospectively. Results were compared with a cohort of patients without cancer from the same center. During the follow‐up period, 136 of 1695 patients developed 141 post‐transplant malignancies (PTM). The cumulative incidence of cancer at 1, 5, 10, 20, and 30 years was 0.64%, 2.42%, 7.89%, 21.49%, and 66.35% respectively. Stomach cancer was the most common PTM. Risk of Kaposi sarcoma, malignant lymphoma, skin cancer, cervical cancer, and renal cell carcinoma was more than 10‐times higher in KT recipients. Multivariate logistic regression analysis showed that cancers were clearly associated with recipients’ age, recipients’ gender, duration of graft function and follow‐up period. Our data suggest that most malignancies develop more frequently after KT, but the incidence of individual cancer is different from Western countries. A more vigorous cancer surveillance program should be adapted to risk associated with transplant recipients, especially older, female or long‐term follow‐up recipients or those with functioning grafts.

Clinical Importance of Intraoperative Cephalic Vein Distensibility as a Predictor of Radiocephalic Arteriovenous Fistula Maturation

Radiocephalic arteriovenous fistula (RCAVF) is the preferred vascular access, but the maturation failure rate is high. Poor vein distensibility is the main cause of maturation failure. There have been several studies regarding vein distensibility, but vein dilation protocol and the cut‐off value predicting maturation failure were inconsistent. We were doubtful that the vein distensibility had been appropriately evaluated, and sought to determine a more clinically applicable parameter. The cephalic vein was dilated via intraluminal hydrostatic pressure during the surgery and the vein size was measured. Maturation failure occurred in 30 patients (22.4%) and was more common in females and in patients who had a previous history of arteriovenous access formation (p = 0.0095 and p = 0.014). The intraoperative postdilation diameter, and the difference between pre and postdilation diameters differed between the two groups (p = 0.0004 and p = 0.0004). The cut‐off value of the postdilation diameter, which indicated a high probability of maturation success, was >4 mm, and the cut‐off value which indicated a higher probability of maturation failure; that is, the difference between the pre and postdilation diameter, was ≤2.2 mm. The degree of distensibility of the cephalic vein may be an important determinant of RCAVF maturation.

The incidence and risk factors for deep vein thrombosis after kidney transplantation in Korea: single-center experience.

The incidence of deep vein thrombosis (DVT) after kidney transplantation (KT) and the risk factors are still unknown in Korean patients. Determining the need for appropriate DVT prophylaxis is difficult when considering the low incidence of DVT in the Asian population. The aim of this study was to investigate the incidence of DVT occurring 3 months after KT, the DVT occurrence pattern, and risk factors in Korean patients.

Mechanical thromboprophylaxis is sufficient to prevent the lower extremity deep vein thrombosis after kidney transplantation

Purpose Deep vein thrombosis (DVT) is a severe and common complication that occurs after the major operation. Despite the commonality of DVT there is limited data on the incidence of DVT after kidney transplantation (KT). Furthermore, most studies have been retrospective in design and were conducted in western countries. The aim of this study was to evaluate the incidence of lower extremity DVT with mechanical thromboprophylaxis within 1 month of KT in Korea. Methods A total of 187 consecutive patients who underwent KT were included in this study. Patients used a graduated elastic stocking (n = 93) or an intermittent pneumatic compression device (n = 94) to prevent DVT. The frequency of DVT during the first month after KT was evaluated using serial color duplex ultrasound on postoperative days 7 ± 2, 14 ± 2, and 28 ± 3. All patients were tested for eight thrombophilic factors before KT. Results DVT occurred in four patients (2.1%) during the first month after KT. All DVT developed in the graduated elastic stocking group. Interestingly, none of the patients had the factor V Leiden mutation or the prothrombin gene 20210A mutation. Conclusion The incidence of DVT in this study was relatively lower than that of western populations. We did not encounter a factor V Leiden mutation or a prothrombin gene 20210A mutation in our study population. These findings suggest that inherited thrombophilic risk factors may be partially responsible for the difference in DVT incidence rates between different nationalities and/or ethnicities.

Incidence of deep vein thrombosis in the first month after kidney transplantation in Korean versus Caucasian populations

Deep vein thrombosis (DVT) in patients undergoing major surgery is a serious complication that can result in pulmonary embolism, pulmonary hypertension, or chronic venous insufficiency of the lower extremities (LEs). The incidence and risk factors for the development of DVT after general surgical procedures have been extensively documented in the literature [1,2]. However, studies analyzing the incidence of DVT in kidney transplant recipients (KTRs) are rare, and those that have been published report contradictory data. Thus, the true frequency of DVT in KTRs is unknown [3–6]. The 8th American College of Chest Physicians (ACCP) guidelines categorize KTRs as a moderate risk group and recommend routine thromboprophylaxis including anticoagulation [1]. The approximate risk of DVT in a moderate-risk group without thromboprophylaxis was reported to be 10-40% in the guidelines, though this was based on data derived mainly from a Caucasian population and may not be applicable to Korean KTRs. Indeed, one epidemiological study reported a significantly lower annual incidence of DVT in Korean populations compared to Caucasian populations [7]. The aim of this study was to evaluate the incidence of LE DVT within the first month after kidney transplant (KT) in Korean patients not receiving chemoprophylaxis.

Prevalence of the Factor XIII Val34Leu Polymorphism in Korean Patients with Deep Vein Thrombosis

OBJECTIVE According to recent reports, a common polymorphism resulting in Val to Leu substitution, located 3 amino acids (Val34Leu) upstream of the thrombin cleavage site of FXIII A, has been related to a lower incidence of deep vein thrombosis (DVT). And, a different expression pattern has been shown across nations and races. However, the frequency of FXIII polymorphism expression in Koreans has not been reported in normal individuals or DVT-patient groups. DESIGN Case-control study in Korean population. METHODS We investigated the distribution of factor XIII Val34Leu polymorphisms in Korean patients of DVT (50 cases) and Korean healthy controls (100 cases), using real-time polymerase chain reaction for single nucleotide polymorphism genotyping. RESULTS With regard to the frequency of the FXIII polymorphism in DVT patients and in the general control group, all 50 cases in the patient group and 100 cases in the control group were found to be Val34 homozygotes. CONCLUSIONS The Val34Leu polymorphism of FXIII was not found in Korean people, and compared with Caucasians, a noticeably low incidence of DVT was shown. Thus, the preventive effect of the Val34 allele of FXIII on the formation of thrombi was shown.

Low-Grade Endometrial Stromal Sarcoma with Inferior Vena Cava Extension: First Report in Korea

Low-grade endometrial stromal sarcoma (LGESS) with intravascular extension is very rare, with only 26 cases having been reported. We experienced a case of LGESS with inferior vena cava (IVC) extension. A 60-year-old female presented with left leg edema. She had a history of total hysterectomy, and was diagnosed of leiomyoma at that time. On imaging study, tumor masses were located around both common iliac veins (CIV), and within the CIV and IVC. The pelvic masses on both side and IVC mass were resected, and then the patient received adjuvant hormonal therapy and radiotherapy over the remnant pelvic masses. LGESS with IVC extension is difficult to distinguish from intravascular leiomyomatosis. LGESS is a malignant disease and commonly recurs, even in early stages. Accurate diagnosis, complete resection, proper adjuvant therapy and close follow-up are very important.

Hybrid Management for Supraceliac Aortic Aneurysm in a High-Risk Patient

To the Editor: An 84‐year‐old male was referred from a local clinic for an incidental thoracoabdominal aortic aneurysm (TAAA) presenting in a supraceliac aortic aneurysm (SCAA) with maximal diameter of 6.0 cm in spine magnetic resonance imaging. He had a medical history of hypertension and chronic obstructive pulmonary disease, and was a 30 pack‐years’ smoker. On physical examination, his vital signs were stable and abdomen was soft without pain and tenderness. Laboratory findings showed white blood cell count of 4840/μl, serum creatinine of 9 mg/L, erythrocyte sedimentation rate of 16 mm/h, and c‐reactive protein of 13.24 mg/L. There was no growth of any microorganism in blood culture. Both tuberculosis polymerase chain reaction and serum acid‐fast bacillus tests were negative. Pulmonary function test showed moderate obstructive lung disease. Computed tomography angiography (CTA) of aorta showed a saccular SCAA with maximal diameter of 6.0 cm, which arose from the posterior aspect of celiac axis level of aorta and enlarged posteriorly [Figure 1a]. The distance between the opening of SCAA and root of superior mesenteric artery (SMA) was 1.5 cm. Hence, we decided to perform a hybrid procedure with aorto‐celiac axis bypass with thoracic endovascular aortic repair under general anesthesia [Figure 1b‐1d]. We performed a cerebrospinal fluid (CSF) drainage perioperatively. Moreover, we performed peri‐aortic dissection and peri‐celiac axis dissection through a midline skin incision. After that, peri‐aortic tunneling with a prosthetic graft (ring‐reinforced polytetrafluoroethylene [PTFE] with diameter of 0.6 cm) through retropancreatic and retrorenal space was performed. And, a distal end of the graft was anastomosed to infrarenal aorta with Prolene #5‐0 (Ethicon, Cincinnati, OH, USA) by end‐to‐side method, and a proximal end of the graft was anastomosed to celiac axis with CV #7‐0 (Gore and Associates, Flagstaff, AZ, USA) by end‐to‐side method [Figure 1b]. After that, we exposed left femoral artery and inserted 6‐Fr sheath through puncturing it. We inserted a guidewire (0.035 Glidewire®; Terumo Medical Corporation, Somerset, NJ, USA) and an angiocatheter (5‐Fr pigtail; Cook Inc., Bloomington, IN, USA) into the aorta, and confirmed the opening of SCAA, root of SMA, and patent graft through an aortography [Figure 1c]. After that, we deployed a stent‐graft (2.8 cm in diameter and 12.0 cm in length; Zenith TX2; Cook Inc., Bloomington, IN, USA) from above the root of SMA to thoracic aorta through a stiff wire (Lunderquist®; Cook Inc., Bloomington, IN, USA; Figure 1d). And, we checked patent PTFE and stent‐graft without endoleak by aortography [Figure 1d]. At one week postoperatively, CTA showed type II endoleak. Moreover, the patient had no symptom. However, at six weeks postoperatively, CTA showed persistent and mild increased type II endoleak [Figure 1e]. Hence, we performed coil embolization (Interlock, Boston Scientific, Natick, MA, USA) in the root of celiac axis through PTFE graft [Figure 1f]. After that, endoleak was improved and the patient was uneventful.

Surgical Management of Symptomatic Adventitial Cystic Disease of the Popliteal Artery as a Cause of Deep Vein Thrombosis

To the Editor: A 67‐year‐old female was referred for persisted swelling in right leg despite of anticoagulation during 2 months for deep vein thrombosis (DVT) of the right popliteal vein (PV). Initial duplex ultrasonography of local clinic at 2 months ago showed the acute DVT of right PV with thrombus and dilated vein [Figure 1a]. She simultaneously complained tingling sensation and claudication in the right leg for several months. She had been on anticoagulation with warfarin (3 mg/d) for 2 months. Moreover, she denied history of hypertension and diabetes mellitus. On physical examination, vital sign was stable, and there was mild swelling in the right leg. However, there was no sign of infection and rest pain in right leg. Portable Doppler showed monophasic arterial flows in the right ankle. Laboratory findings showed prothrombin time international normalized ratio of 2.27, D‐dimer of 1.54 μg/ml, and C‐reactive protein of 0.22 mg/L. We checked computed tomography angiography (CTA), and it showed right popliteal artery (PA) focally occluded and PV totally collapsed by 3 cm‐sized and low‐density cystic mass. In addition, DVT was not detected and greater saphenous vein was patent in CTA [Figure 1b and 1c]. Hence, we thought DVT of PV might be resolved. We decided to perform cyst excision and interposition of PA with saphenous vein. Hence, we switched warfarin into low molecular weight heparin for 1‐week preoperatively. Under general anesthesia, the patient was positioned pronely for posterior approach. We performed S‐shaped skin incision on right popliteal area and exposed small saphenous vein (SSV). Fortunately, SSV was favorable for vein graft and was harvested. After that, PV, PA, and cyst were exposed. There were severe inflammation around PV and PA. Hence, we carefully dissected those lesions [Figure 1d]. PV was totally compressed by the cyst, and there was wall thickening in PV [Figure 1d]. We thought thrombus of PV might have been resolved. During excision of cyst, we detected communication between adventitia of PA and cyst [Figure 1d]. However, there was no communication between joint cavity and cyst. We performed arteriotomy and checked nearly occlusion with intimal hyperplasia in artery wall. So, we performed segmental resection of PA and interposition with a reversed ipsilateral SSV graft [Figure 1e]. After that, we checked patent graft and good distal arterial flows by portable Doppler. The resected cyst grossly contained transparent gelatinous material, and pathological examination showed cystic space formed between media and adventitia was containing mucoid material [Figure 1f]. At 1‐week postoperatively, CTA showed that graft was patent with good flow in distal arteries, and there was no remnant cystic lesion in popliteal area [Figure 1g and 1h]. After the surgery, the patient’s symptoms were improved. Anticoagulation was stopped at 1 month postoperatively. At 10 months’ postoperatively, CTA showed that graft was patent without recurrent stenosis of PA.