INTRODUCTIONThe key to treatment of a thrombosed dialysis graft is restoration and maintenance of function as long as possible. The objective of this study was to compare the outcomes of pharmacomechanical thrombolysis and surgical thrombectomy in the treatment of thrombosed haemodialysis grafts.

MATERIALS AND METHODSDuring a 3-year period, 108 patients with 114 thrombosed dialysis grafts were referred to our institute for treatment. Fifty thrombosed dialysis grafts underwent pulse-spray catheter thrombolysis using recombinant tissue plasminogen activator (rt-PA) with angioplasty, and 64 thrombosed dialysis grafts underwent surgical thrombectomy. The procedural success rates, complications and average patency times and patency rates were compared between the 2 procedures. P values less than 0.05 were considered to be statistically significant.

RESULTSThere were no statistically significant differences between the pharmacomechanical thrombolysis group and the thrombectomy group in the procedural success rates (94% and 93.8%, P = 0.15) or average patency times (6.24 months and 6.30 months, P = 0.17). The primary and secondary patency rates at 12 months were 28.0% ± 8.4% and 54.3% ± 7.8% for the thrombolysis with angioplasty group, and 30.0% ± 6.3% and 57.0% ± 4.8% for the thrombectomy group, respectively (P = 0.65 and P = 0.49, respectively). There were no procedural-related major complications.

CONCLUSIONOur study found no differences in outcomes between patients treated with pharmacomechanical thrombolysis and surgical thrombectomy for thrombosed haemodialysis grafts. Pharmacomechanical thrombolysis can be considered as an alternative treatment for dialysis graft thrombosis.

Aged ; Arteriovenous Shunt, Surgical ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Thrombectomy ; methods ; Thrombosis ; drug therapy

Sutures may cause endothelial trauma and occlusion. The vascular clip system (VCS) clip applier may minimize endothelial injury. Fourteen carotid arteries of nine adult rabbits were transected and re-anastomosed with either #7-0 polypropylene (Group I, n=8) or VCS clips (Group II, n=6). The animals were sacrificed at 1, 3, 8, 14, and 30 days postoperatively. The operation time and bleeding amount were checked for each anastomosis. Carotid angiograms, photography, H&E staining and scanning electron microscopy (SEM) were performed. Fibrin and thrombus, inflammatory cell infiltration, endothelial disruption, luminal distortion, fibrosis, and wall thickening were compared. The luminal diameter was greater in group II. There were minimal differences in thrombosis, wall thickening and fibrosis between the two groups. However, fibrin, inflammatory cell infiltration, multinucleated giant cell formation, endothelial disruption, and luminal distortion were greater in group I. On SEM, group I showed trans-mural penetration. In contrast, group II showed suture margin eversion and no transmural penetration. Stenosis was greater in group I than in group II on carotid angiogram. The operation time was shorter in group II than in group I, i.e. 5+/-1.4 min vs. 11+/-3.8 min, respectively. The current data showed similar or superior results with VCS clips in comparison to conventional suturing with polypropylene.
Angiography ; Animal ; Arteriovenous Shunt, Surgical/*instrumentation/methods ; Carotid Arteries/pathology/*surgery/ultrastructure ; Microscopy, Electron, Scanning ; Rabbits ; Surgical Stapling/*instrumentation/methods

BACKGROUNDThe resection and reconstruction of the hepatic artery is often required in radical surgery for hilar cholangiocarcinoma. In this study, we report our experience in performing arterioportal shunting as an alternative for the arterial reconstruction.

METHODSFour patients with hilar cholangiocarcinoma underwent extended left hepatectomy and caudate lobectomy combined with en bloc resection of the hepatic artery and arterioportal shunting with restriction of the arterial caliber. The efficacy of arterioportal shunting was assessed by computed tomography angiography (CTA).

RESULTSAll the four patients recovered uneventfully without any complications. CTA showed a patent shunt and normal liver regeneration. No signs of portal hypertension were found at one year of follow-up.

CONCLUSIONSArterioportal shunting with restriction of the arterial caliber appears to be a feasible and safe alternative for the microvascular reconstruction after hepatic artery resection in radical surgery for hilar cholangiocarcinoma.

Arteriovenous Shunt, Surgical ; methods ; Bile Duct Neoplasms ; surgery ; Cholangiocarcinoma ; surgery ; Female ; Humans ; Male ; Middle Aged ; Portal Vein ; surgery ; Treatment Outcome

Arteriovenous Shunt, Surgical ; Blood Vessel Prosthesis ; Blood Vessels ; pathology ; Humans ; Neoplasms ; blood supply ; pathology ; surgery ; Vascular Surgical Procedures ; instrumentation ; methods ; Vena Cava Filters

INTRODUCTIONOne complication of autogenous arteriovenous fistula (AVF) for haemodialysis is the formation of a venous aneurysm.

CLINICAL PICTUREThe clinical picture is typically an expanding aneurysm leading to skin atrophy and ulceration with the risk of rupture and infection. Aneurysm also reduces the potential cannulation area.

TREATMENTThe cases described here used a surgical 'remodelling' technique involving complete skeletonisation of the venous aneurysm, reduction of lumen diameter and retention of vein wall using a Hegar dilatator to remodel a new fistula.

OUTCOMESix patients were treated using this method and the arterior venous shunt (AVS) was used for haemodialysis the following day. No recurrent aneurysm developed.

CONCLUSIONRemodelling of aneurysmal AVF is an effective and low-risk option for managing this kind of complication, allowing direct access for haemodialysis.

Aneurysm ; etiology ; surgery ; Arteriovenous Shunt, Surgical ; adverse effects ; Catheters, Indwelling ; Humans ; Postoperative Complications ; Renal Dialysis ; adverse effects ; methods ; Vascular Surgical Procedures

To evaluate the feasibility and accuracy of contrast-enhanced ultrasonography (CEUS) for the measurement of hemodialysis access recirculation (AR) and access flow rate (Qa), a two pump system was used to simulate access and dialyzer flow. AR and Qa under different conditions, such as reversal connection of dialysis lines and the needle orientation, were compared with each other. The value of access flow and recirculation flow were calculated based on the formulas introduced in this paper, and the correlation and consistency between true flow rate and calculated values were analyzed. The measured R correlated well with true value of flow rate (r = 0.57, P = 0.038, Qa > Qb; r = 0.95, P = 0.001, Qa < Qb). The Bland-altman test showed good agreement between the calculated value based on CEUS and true values. The CEUS can be used as a new advanced technology for AR and Qa measurement.
Arteriovenous Shunt, Surgical ; Blood Flow Velocity ; Computer Simulation ; Contrast Media ; Humans ; Kidney Failure, Chronic ; blood ; therapy ; Models, Biological ; Monitoring, Physiologic ; instrumentation ; Regional Blood Flow ; Renal Dialysis ; methods ; Ultrasonography

INTRODUCTIONAn arteriovenous fistula (AVF) is the preferred method for haemodialysis in patients with end-stage renal failure. Previous studies have shown value in attempting percutaneous transluminal angioplasty (PTA) to salvage AVFs that fail to mature, but they are relatively small in size and mainly reported in Western populations. We reviewed our data of PTA in non-maturing AVFs to establish whether this technique is translatable to our local multiethnic population.

MATERIALS AND METHODSWe retrospectively reviewed the medical records and procedural images of 105 patients who had PTA for non-maturing AVFs performed at our department from January 2008 to January 2011. Technical success was defined as ≤30% residual stenosis after angioplasty. Clinical success was defined as at least 1 successful haemodialysis session within 4 weeks after PTA.

RESULTSAll 105 patients underwent angioplasty for at least 1 haemodynamically significant stenosis. Six (5.7%) had additional embolisation of accessory veins. Technical success was achieved in 95.2% of cases. The clinical success rate was 76.2%. Primary patency rates at 3, 6 and 12 months were 83%, 45% and 28%, respectively. Secondary patency rates at 3, 6 and 12 months were 90%, 79% and 70%, respectively. The minor complication rate was 18.1%. No major complications were encountered. An average of 1.7 interventions per access-year was required to maintain AVF patency. Patients with a preoperative vein size >2.0 mm and age <55 years were more likely to achieve clinical success, although not statistically significant.

CONCLUSIONPTA is a viable option to help salvage non-maturing AVFs in a multiethnic Asian population.

Angioplasty ; methods ; Arteriovenous Shunt, Surgical ; Constriction, Pathologic ; therapy ; Embolization, Therapeutic ; Female ; Humans ; Kidney Failure, Chronic ; therapy ; Male ; Middle Aged ; Renal Dialysis ; Reoperation ; Retrospective Studies ; Singapore ; Veins

BACKGROUNDHilar cholangiocarcinoma is a malignant tumor that is difficult to cure. The aim of this study was to observe the effects of flow-controlled partial portal vein arterializations (PPVA) on liver regeneration after hepatectomy in minipigs with chronic obstructive jaundice.

METHODSEight minipigs were made into chronic obstructive jaundice models. United semi-hepatectomy, which imitates extended radical surgery for treatment of hilar cholangiocarcinoma, was then performed. The eight minipigs were randomly divided into groups A and B (n = 4 minipigs each). PPVA was performed in Group A but not in Group B. The effects of flow-controlled PPVA on live regeneration after hepatectomy were observed for 30 days after hepatectomy.

RESULTSThe portal vein PO(2) at the immediate time point and on postoperative day 30 was higher in Group A ((47.33 ± 2.43) and (48.50 ± 4.44) mmHg) than in Group B ((35.38 ± 4.06) and (35.55 ± 2.55) mmHg respectively, all P < 0.01). The mitotic index of liver cells on postoperative days 14 and 21 was higher in Group A (12.55% ± 2.85% and 15.25% ± 1.99% respectively) than in Group B (6.85% ± 2.10% and 11.88% ± 1.15% respectively, all P < 0.05). The regeneration rate of residual liver on postoperative days 14 and 21 was higher in Group A (24.56% ± 6.15% and 70.63% ± 9.83% respectively) than in Group B (11.96% ± 5.43% and 44.92% ± 7.42% respectively, P < 0.05 and P < 0.01 respectively).

CONCLUSIONFlow-controlled PPVA can promote liver regeneration after hepatectomy and prevent liver failure in minipigs with chronic obstructive jaundice.

Acepromazine ; therapeutic use ; Animals ; Arteriovenous Shunt, Surgical ; methods ; Atropine ; therapeutic use ; Female ; Hepatectomy ; methods ; Jaundice, Obstructive ; surgery ; Ketamine ; therapeutic use ; Liver Regeneration ; physiology ; Portal Vein ; surgery ; Swine ; Swine, Miniature

OBJECTIVE: To determine the efficacy and outcome of percutaneous treatment in restoring the function of failed native arteriovenous fistulas (AVFs) where pulse-spray pharmacomechanical thrombolysis was used as the primary mode of therapy. MATERIALS AND METHODS: From June 2001 to July 2005, 14 patients who had thrombosis of native AVFs underwent percutaneous restoration following 20 episodes of thrombosis. These included 6 repeated episodes in one forearm AVF and two episodes in another forearm AVF. All patients except one were treated with urokinase injection utilizing the pulse-spray technique and had subsequent balloon angioplasty. One patient was treated by percutaneous angioplasty alone. We retrospectively evaluated the feasibility of percutaneous treatment in restoring the function of the failed AVFs. The primary and secondary patencies were calculated by using a Kaplan-Meier analysis. RESULTS: Both technical and clinical success were achieved in 15 (75%) of 20 AVFs. Four of the five technical failures resulted from a failure to cross the occluded segment. One patient refused further participation in the trial through a brachial artery access following failure to cross the occluded segment via an initial retrograde venous puncture. There were no major precedure related complications observed. Including the initial technical failures, primary patency rates at six and 12 months were 64% and 55%, respectively. Secondary patency rates at six and 12 months were 71% and 63%, respectively. CONCLUSION: Pulse-spray pharmacomechanical thrombolysis for treatment of the thrombosed AVFs is safe, effective and durable. This procedure should be considered as an option for the management of failed AVFs prior to surgical intervention.
Treatment Outcome ; Treatment Failure ; Thrombosis/*etiology/*prevention & control ; Thrombolytic Therapy/*methods ; Renal Dialysis/*adverse effects ; Pulse Therapy, Drug ; Middle Aged ; Male ; Humans ; Fibrinolytic Agents/*administration & dosage ; Female ; Arteriovenous Shunt, Surgical/*adverse effects ; Aged ; Adult

Endovascular procedures are becoming the standard type of care for the management of hemodialysis vascular access dysfunction. As with any type of medical procedure, these techniques can result in procedure-related complications, although the expected number of complications is low. The clinical extent of these complications varies from case to case. Management of these cases depends on the clinical presentation. Major complications such as vein rupture, arterial embolism, remote site bleeding or hematoma, symptomatic pulmonary embolism and puncture site complications necessitating treatment require major therapy. Minor complications such as non-flow compromising small puncture site hematoma or pseudoaneurysms require little or no therapy. It is essential that the interventionist be prepared to manage these complications appropriately when they arise.
Veins ; Stents ; Rupture, Spontaneous ; Retrospective Studies ; Renal Dialysis/*methods ; Postoperative Complications/therapy ; Middle Aged ; Male ; Humans ; Female ; Extravasation of Diagnostic and Therapeutic Materials/therapy ; Embolism/therapy ; *Arteriovenous Shunt, Surgical ; Aged ; Adult