An unusual case of fistula formation and thrombosis between arteriovenous graft and a native vein

Arteriovenous graft for hemodialysis vascular access is a widely used technique with many advantages. However, it has crucial complications with graft thrombosis and infection. We recently experienced an unusual case of arteriovenous graft complication involving graft thrombosis related to fistula formation between the graft and the natural vein with infection. We diagnosed this condition using Doppler ultrasound and computed tomography angiography. Successful surgical treatment including partial graft excision and creation of a secondary arteriovenous fistula using an inadvertently dilated cephalic vein was performed. The dialysis unit staff should keep this condition in mind and try to prevent this complication.

Successful Treatment of Prosthetic Graft Infection 7 Years after Ascending Aorta Replacement and Aortic Root Replacement with a Freestyle Stentless Valve / 日本心臓血管外科学会雑誌

A 62 year-old man presented with severe septic shock complicated by prosthetic graft infection, 7 years after aortic root replacement with a Freestyle stentless valve and graft replacement of the ascending aorta. We initially managed the patient with antimicrobial therapy for 2 months and subsequently surgery was performed, replacing the infected aortic graft with rifampicin-bonded prostheses, and added omentopexy. The infection was cured and has not recurred.

Which Graft must be Preferred in Firearm Injury of the Axillary Artery.

Aims: Interposition graft technique is used mostly in firearm wounds of axillary artery, because of excessive defect of the vessel. Autologous vein has been preferred in general application, even though there is a mild size discrepancy between native artery and autologous vein. However, in many series, prosthetic graft infection risk has been reported as low. Presentation of Case: I am presenting a patient with a gunshot wound to the right upper chest. As a first choice I preferred saphenous vein which was occluded by thrombosis at the post-repair third week in spite of anticoagulant therapy and was replaced with prosthetic graft which was patent at the eight month follow-up. Discussion: Although the theoretical risk of infection of prosthetic grafts, many previous reports have demonstrated that prosthetic grafts are nearly as safe as autologous grafts and they have high long-term patency rate. Conclusion: There is no point in insisting on autologous grafts in cases of the diameter discrepancy between native artery and autologous graft, prosthetic graft may be used more frequently in axillary artery trauma, and post-repair anticoagulants may be administered in the consequences of size discrepancy between the native artery and the graft.

The Clinical Application of Duplex Ultrasonography in Evaluating the Restenosis of Peripheral Arterial Bypass Graft Postoperatively / 天津医药

Objective To explore the clinical value of the duplex ultrasonography (duplex US) for evaluating the re-stenosis after peripheral arterial bypass grafting. Methods Eighty prosthetic grafts of sixty-three patients with femoral-pop-liteal arterial bypass grafting were follow-up regularly by duplex US. They were divided into non significant stenosis group (n=56), the significant stenosis group (n=15) and occlusion group (n=9) according to the tube diameter and arterial blood flow-ing parameters, which changed postoperatively. The diagnostic results were compared and analyzed between duplex US and digital subtraction angiography (DSA). The peak flow velocity of middle grafts (MG) to 40 cm/s was defined to evaluate risk of graft occlusion. Results The diagnostic coincidence rate of duplex US and DSA for grafts stenosis classification was 90%. The diagnostic sensitivity of duplex US to grafts stenosis was 91.7%, and the specificity was 92.9%. The positive pre-dictive value was 84.6%for grafts stenosis, and the negative predictive value was 96.3%, the false positive rate was 16.7%, and the false negative rate was 8.3%. The grafts occlusion rate was higher in MG<40 cm/s group than that of MG≥40 cm/s group. Conclusion There was a good consistency with Duplex US and DSA for the diagnosis of peripheral artery bypass graft restenosis. Duplex US showed characteristics of non-invasive, simple and easily accepted by patients.

A Case of Vascular Graft Infection by <i>Aspergillus </i>Causing Distal Embolism to the Foot / 日本心臓血管外科学会雑誌

A 77-year-old woman with previous aortic grafting for abdominal aortic and iliac artery aneurysms developed a blue toe in her left foot. Enhanced CT showed a high density area around the vascular graft of the left iliac artery, which partially protruded into the graft. Because of the elevated <i>β</i>-D glucan level, fungal infection of the vascular graft was strongly suspected. Her general condition precluded the graft removal. Instead, thrombectomy was performed. Microbial examination of the removed clot revealed infection by <i>Aspergillus fumigatus</i>. Voriconazole was administered for 3 months. The <i>β</i>-D glucan level was normalized. Only thrombectomy and Voriconazole administration can be an alternative in case with vascular graft infection by <i>Aspergillus</i>.

A Successfully Treated Surgical Case of Graft Duodenal and Colonic Fistula with Cardiopulmonary Arrest after Abdominal Aortic Graft Replacement / 日本心臓血管外科学会雑誌

A secondary aorto-enteric fistula can directly communicate with the gastroduodenal tract, colonic tract and the aorta in patients undergoing major surgery on the aorta, and this phenomenon is observed particularly often in patients who have undergone abdominal aortic graft replacement. We encountered a case of secondary aortoduodenal fistula and colonic fistula. The patient was a 60-year-old man who had previously undergone a graft replacement for an infra-renal abdominal aortic aneurysm. His present admission was due to episodes of gastro-intestinal hemorrhaging and he had also undergone an abdominal aortic graft replacement 2 months previously. The patient's bleeding was managed conservatively. A scar was observed in the duodenum based on the endoscopic findings. At 10 days after admission, abdominal computed tomography (CT) showed active bleeding from the graft in the third portion of the duodenum. We therefore diagnosed secondary aorto-duodenal fistula. Since this pathogenic state may lead to serious massive gastroduodenal hemorrhaging, both an accurate diagnosis and emergency operation are therefore essential to successful treatment. We immediately inserted an intra-aortic occlusion balloon catheter (IABO). Thereafter, another aorto colonic fistula was detected after laparotomy, for the first time. First, the old graft was removed and the direct closure of the duodenum was performed, followed by omentopexy, colostomy, colostoma and then the extra-anatomical revascularization between the left axillary and bilateral femoral arteries was carried out. Finally, an intestinal feeding tube was inserted. The patient fell into a state of cardiac arrest during the operation due to the uncontrolled active bleeding in spite of the presence of IABO. An emergency thoracotomy was thus performed in the left 4th intercostal region. The descending aorta was clamped, and then all of the planned procedures were performed in order. The postoperative course was eventful, however, the patient's lower thigh eventually had to be amputated due to ischemia of the clamped descending aorta. We encountered a case of graft duodenal and colonic fistula with cardio pulmonary arrest due to delayed diagnosis based on the endoscopic findings after abdominal aortic graft replacement. This case was successfully treated despite various difficulties in making a timely and accurate diagnosis.

Anterior Small Thoracotomy Drainage and Intermittent Lavage in 2 Cases of Prosthetic Graft Infection after Arch Replacement Surgery / 日本心臓血管外科学会雑誌

Prosthetic graft infection after arch replacement surgery is a serious complication that is often resistant to antibiotics. However, graft replacement is difficult and is very invasive. We performed anterior small thoracotomy drainage and intermittent lavage in 2 patients. First, the prosthetic graft was approached via a left third intercostal thoracotomy. After the ablation of infected tissues and cleansing with saline, drains were placed both proximally and distally to the vascular graft. An irrigation withdrawal drain was then implanted in the left thoracic cavity. After surgery, diluted povidone iodine solution, pyoktanin solution, and saline were used for pleural lavage. Case 1 : An 82-year-old man underwent arch replacement for a ruptured aortic arch aneurysm in November 2005. He suffered from high-grade fever from March 2008 and was referred to our hospital from another hospital with a diagnosis of vascular graft infection. A small anterior thoracotomy and drainage were performed on April 9. Pleural lavage with povidone iodine solution was performed 9 days after surgery, then was performed with saline from days 10-13 after surgery. The patient was discharged on postoperative day 30. Case 2 : A 58-year-old man complained of high-grade fever from March 16, 2009. He had undergone arch replacement for an aortic arch aneurysm in 1997. He consulted a physician and was referred to our hospital with a diagnosis of vascular graft infection. Methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA) was identified by blood culture. A small anterior thoracotomy and drainage were performed on March 24. Immediately after surgery pleural lavage was performed with pyoktanin blue solution changing to povidone iodine on postoperative day 10. Pleural lavage was continued until day 34, and the patient was discharged on postoperative day 64. In both cases, drainage and pleural lavage with antibiotic solutions improved the patients' general condition. The infections have not recurred since discharge. Small anterior thoracotomy for graft infection after arch replacement, in addition to being minimally invasive, can avoid the need for a second median sternotomy, and can provide an adequate view of the full length of the arch prosthetic graft.

FDG Uptake Pattern of a Prosthetic Graft without Infection on a PET/CT Scan

PURPOSE: A prosthetic graft infection is a rare but often disastrous complication during vascular surgery. Diagnosis of a prosthetic graft infection is not always easy, particularly with a low virulent bacterial infection or in a deeply placed graft in the retroperitoneal space. Recently, fludeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) has been proposed as a diagnostic modality for prosthetic graft infection. However, some reports have indicated that high FDG uptake occur in grafts without infections. This study analyzed FDG uptake patterns in prosthetic grafts of asymptomatic patients. METHODS: We reviewed 14,545 patients who had received PET/CT in a tertiary hospital between July 2007 and March 2010. Of them, 11 patients who had undergone previous bypass surgery with a prosthetic graft were identified. Four underwent an aortic bypass and the others received lower extremity bypass grafting. PET/CT images and patient clinical data were reviewed retrospectively. The maximum standardized uptake value (SUVmax, A) in the graft, the mean SUV (SUVmean, B) of the blood-pool, and the target-to-background ratio (T/B, A/B) were calculated. RESULTS: The mean duration between bypass grafting and the PET/CT scan was 21 months (range, 1~80 months). No clinical evidence of graft infection was observed in any of the patients. PET/CT revealed an uneven, diffuse FDG uptake pattern on the grafts, and the mean T/B was 2.0 (range, 0.9~4.6). T/B was greater than 2.0 in six patients (55%). CONCLUSION: A prosthetic graft without an infection can result in increased FDG uptake during PET/CT. A further prospective study is necessary to evaluate the usefulness of FDG PET/CT for diagnosing a prosthetic graft infection.

Clinical Feature of Iatrogenic Fistulas between Prosthetic Graft and Native Vein in CRF Patients

PURPOSE: Failure of hemodialysis access is the main medical problem in chronic renal failure patients. This resulted from complications such as thrombosis, infection, pseudoaneurysm, steal syndrome and so on. This study was undertaken in an attempt to describe the clinical characteristics and significances of dialysis failure due to iatrogenic fistula between prosthetic graft and native vein at puncture site. METHODS: During 5 years between Feb. 2005 and Feb. 2009, five Iatrogenic fistulas were identified in a retrospective review of 133 patients performed 220 times fistulography due to dialysis failure in PTFE (polytetrafluoroethylene) graft. RESULTS: Overall incidence is 3.8 % in PTFE graft cases. Mean age is 50 (28~75) years, male to female ratio 2:3. Median 1st patency period is 20 months (6~36). All iatrogenic fistula is usually located in not venous but arterial limb of forearm loop, combined with the stenosis in venous limb and anastomosis site. More than 70% venous anastmotic stenosis in 4 cases (80%) and diffuse stenosis of venous limb in 3 cases (60%), revised concomitantly either by patch angioplasty or ballooning. Medial follow-up period is 8 months (5~12), graft occlusion occurred in one case. CONCLUSION: All iatrogenic fistula usually occurs in not venous but arterial limb of forearm loop graft. Most iatrogenic fistula is combined with the stenosis in venous limb and anastomosis sites, must be revised concomitantly either by patch angioplasty or ballooning. Close assessment to superficial vein and graft is needed for early detection. Fistulography is the most useful diagnostic tool. Careful cannulation method is required to prevent the occurrence of iatrogenic fistula in chronic renal failure patients.

False Aneurysm in the Right Groin due to Disruption of a Knitted Dacron Prosthesis / 日本心臓血管外科学会雑誌

A 75-year-old man was admitted to our hospital with a pulsatile mass in the bilateral groin. He had received placement of a Y-shaped Cooley double velour knitted Dacron graft 20 years previously for arteriosclerosis obliterans. Computed tomography demonstrated an aneurysm near the distal anastomosis of the graft. Based on a clinical diagnosis of a non-anastomotic aneurysm, an operation was performed. When the right aneurysm was incised, it was found that the anastomosis of the graft to the common femoral artery was intact and that the graft itself had a defect, 1.5 cm in size near the distal anastomosis of the graft. The final diagnosis of the right groin aneurysm was a non-anastomotic false aneurysm due to prosthetic graft failure. The left groin aneurysm was a true aneurysm due to arteriosclerosis. After resection of the bilateral aneurysm, graft interposition with an expanded polytetrafluoroethylene (ePTFE) graft was successfully performed. Generally, arterial grafts below the groin are subject to high levels of mechanical stress, and graft failure is not uncommon. Vascular surgeons should keep in mind that graft failure is not rare in patients with long-standing prosthetic graft.