Arthroscopic assisted femoral tunnel drilling for the intra-articular anatomic cranial cruciate ligament reconstruction in dogs.

OBJECTIVE: To develop and test an arthroscopic aiming device for extra- to intra-articular femoral tunnel drilling emerging at the center of the femoral insertion of the cranial cruciate ligament (CrCL) in medium to large breed dogs. MATERIAL AND METHODS: Hindlimbs (n = 12) of six cadaveric dogs (≥ 20 kg bodyweight). One hindlimb from each cadaver was randomly chosen. On a standard medio-lateral stifle radiograph the caudo-cranial position of the CrCL center was measured and transferred onto an adjustable aiming device. After arthroscopic debridement of the CrCL the aiming device was hooked behind the lateral condyle and a 2.4 mm guide pin was placed from extra- to intra-articular. The intra-articular position of the resulting bone tunnel was evaluated radiographically as well as compared to the anatomic CrCl center of the contralateral hindlimb using 3D renderings. RESULTS: According to the postoperative radiographs all six drill tunnels were located at or near the CrCL center. The median absolute 3D error from the anatomical center of the CrCL was 0.6 mm (range: 0.2-0.9 mm). CONCLUSION: Precise anatomic placement of the femoral tunnel for intra-articular repair of the CrCL was achieved using an adjustable aiming device. CLINICAL RELEVANCE: The proposed technique will reduce femoral tunnel misplacement when performing intra-articular CrCL repair in dogs. In combination with the published technique for arthroscopic tibial tunnel drilling using a similar aiming device, the technical requirements for arthroscopic assisted tunnel positioning for anatomical graft replacement are available.

Ultrasonography alone can reliably locate parathyroid tumours and facilitates minimally invasive parathyroidectomy.

INTRODUCTION: Minimally invasive parathyroidectomy (MIP) is performed via a short incision (≤3cm). Previous studies have employed multiple imaging modalities including ultrasonography, sestamibi imaging and/or intraoperative parathyroid hormone assay. We present our eight-year experience of MIP using ultrasonography alone. METHODS: One hundred parathyroidectomies performed by a single surgeon between April 2004 and December 2012 were identified in a prospectively maintained database. All patients underwent ultrasonography including preoperative marking of the lesion by a single radiologist. No other localising diagnostic tests were performed. RESULTS: Of the 100 patients (69% female) who underwent parathyroidectomy, 93 had MIP. The median age of all cases was 58 years (range: 19-90 years). All patients exhibited an elevated parathyroid hormone level (median: 19pmol) in the presence of hypercalcaemia (median: 2.86mmol/l, range: 2.54-3.94mmol/l). Conventional surgery was indicated in seven patients owing to the need for concurrent thyroidectomy. The median operative time was 30 minutes (range: 10-130 minutes). Ultrasonography localised parathyroid tumour position correctly in 98% of patients who underwent MIP, and in 97% across both MIP and non-MIP groups. Postoperative complications requiring treatment included pancreatitis and symptomatic hypocalcaemia. Follow-up review at 6-8 weeks demonstrated that 86% of open cases (6/7) and 94% of MIP cases (87/93) were rendered normocalcaemic. CONCLUSIONS: Our study is the first to demonstrate that the sole use of ultrasonography including preoperative marking can localise parathyroid tumours correctly in 98% of cases suitable for MIP.

Reprinted article "Subintimal angioplasty of femoropopliteal artery occlusions: the long-term results".

The technique of subintimal angioplasty has been attempted on 200 consecutive femoropopliteal artery occlusions of median (range) length 11 (2-37) cm. The principle of the technique is to traverse the occlusion in the subintimal plane and recanalise by inflating the angioplasty balloon within the subintimal space. The technical success rate was 159/200 (80%) and was not significantly different for occlusions <10 cm (81%, n = 73), 11-20 cm (83%, n = 63) or >20 cm (68%, n = 23), p = 0.20. There were no deaths nor limb loss resulting from the procedure. The median (range) ankle-brachial pressure index increased from 0.61 (0.21-1.0) preangioplasty to 0.90 (0.26-1.50) postangioplasty. The actuarial haemodynamic patencies of technically successful procedures at 12 and 36 months were 71% and 58% respectively, the symptomatic patencies were 73% and 61%. A multiple regression analysis showed that smoking multiplied the risk of reocclusion by 2.70 (p < 0.001), each additional run-off vessel reduced the risk by 0.54 (p < 0.001) and the risk increased by 1.73 (p = 0.020) for every 10 cm of occlusion length. In conclusion, the technical success rate (80%) of subintimal angioplasty for femoropopliteal occlusions is unrelated to occlusion length and for all procedures, including technical failures, cumulative symptomatic and haemodynamic patencies of 46 and 48% can be achieved at 3 years. The factors influencing long-term patency were smoking, the number of calf run-off vessels and occlusion length.

Developments in subintimal angioplasty in the infrainguinal segment.

Since it was first described in 1990, subintimal angioplasty (SIA) has become an established percutaneous procedure for the treatment of symptomatic lower limb arterial occlusions. The concept of this technique is to create a dissection in the subintimal plane in order to cross an occluded intraluminal segment, then to re-enter the true lumen of the patent distal artery. Balloon dilatation of this subintimal channel results in a new extraluminal lumen that is free of atheromatous plaque. It is a safe and effective procedure with advantages over intraluminal angioplasty and open surgery, thereby increasing the scope of endovascular therapy to include complex infrapopliteal occlusions and high-risk patients with limb-threatening ischaemia who are unsuitable for surgical revascularization. It has good primary success rates, long-term outcomes and does not compromise future surgical revascularization, resulting in a paradigm shift in the management of lower limb ischemia with many centres adopting SIA as first-line therapy. This article aims to review the indications of SIA, variations and developments in the technique, outcomes and factors affecting patency, and complications associated with the procedure.

Subintimal angioplasty: meta-analytical evidence of clinical utility.

OBJECTIVES: The aim of this study was to determine accurate estimates of the success rate of subintimal angioplasty in terms of ability to recanalise occluded vessels, patency over time and limb salvage rates. DESIGN: A meta-analysis of published literature. MATERIALS: All studies reporting unique patient data published in English language between 1989 and 2008. METHODS: Separate meta-analyses were performed for immediate technical success, 12-month patency rates and 12-month limb salvage rates. Longer-term outcomes were analyzed in separate meta-analyses. Meta-regression was applied to determine whether any of these outcomes had improved over time. RESULTS: Pooled estimates for technical success, primary patency at 12 months and limb salvage at 12 months were 85.7% (95% confidence interval: 83.3%-87.7%, 2810 limbs), 55.8% (95% confidence interval: 47.9%-63.4%, 1342 limbs), and 89.3% (95% confidence interval: 85.5%-92.2%, 2810 limbs), respectively. Regression analysis demonstrated no significant change in outcomes over time. There was some evidence of publication bias, however, after adjusting for this there was little change in the pooled outcome estimates. CONCLUSIONS: This study demonstrates that the outcomes for subintimal angioplasty are good and that this method should be considered as an alternative to surgical bypass.

Below the knee angioplasty among diabetic patients.

The treatment of below knee arterial disease has undergone a gradual shift over the last few years to incorporate a greater proportion of endovascular treatments. Not only does this include patients who now have endovascular therapy rather than surgery, but also patients who in the past would have been offered supportive treatment only, due to factors such as being medically unfit for surgery, lacking sufficient donor vein for bypass grafting, or swelling. Diabetes mellitus is becoming increasingly common, potentially causing numerous comorbidities in patients. It tends to have a more distal pattern of peripheral vascular disease, presenting later and with generally high complication and failure rates following therapy (surgical or endovascular) and higher amputation rates. Given these comorbidities, the reduced morbidity and mortality of endovascular treatments may be beneficial in treating below-knee arterial disease. The success and complication rates of endovascular therapy vary between treatment for claudication and critical limb ischaemia, though success rates are improving and in some cases are comparable to the current gold standard of surgical bypass.

Revascularization strategies in below the knee interventions.

Until recently the role of endovascular revascularization in the infrapopliteal arteries was limited. Endo-vascular management including percutaneous transluminal angioplasty and subintimal angioplasty is now being considered as a primary alternative in critical limb ischaemia revascularization with a decreasing number of major amputations (above the ankle) performed. Endovascular treatment has been shown to have reduced morbidity and hospital stay compared to revascularization surgery with greater cost-effectiveness and better patient quality of life compared with major amputation.

Subintimal angioplasty of a crural vessel via an antegrade popliteal artery puncture.

Percutaneous retrograde puncture of the popliteal artery is a well-described technique and offers an alternative site for access to the peripheral vascular system. Antegrade popliteal artery puncture has only been described once in the literature. We present a case of subintimal angioplasty of a crural vessel occlusion using an antegrade popliteal approach. This report highlights that if other access is not possible due to unfavourable anatomy this approach is a technically feasible option.

Treatment of chronic mesenteric ischemia by subintimal angioplasty of an occluded superior mesenteric artery.

INTRODUCTION: Subintimal angioplasty is an established technique for the recanalisation of occluded vessels. It has been applied extensively to the peripheral arterial system but not the mesenteric vessels in mesenteric angina. REPORT: We report the first described case of recanalisation of a mesenteric vessel. The vessel has remained patent for five years with good symptomatic relief. DISCUSSION: Subintimal angioplasty could represent an alternative treatment to major surgery for occlusive disease of the mesenteric vessels.

Subintimal angioplasty in the management of lower limb ischaemia.

It is now almost 20 years since subintimal angioplasty (SIA) was pioneered. This cost-effective technique has over the past few years enjoyed a dramatic resurgence of interest and application, particularly after having been identified as a safe and practicable approach to vascular recanalisation in several international publications. Originally used in the femoropopliteal segment, its role has been extended to the treatment of infrapopliteal lesions, including the recanalization of the trifurcation and long tibial occlusions. Experienced centres have repeatedly reported primary success rates of around 90% in the infrainguinal vessels, as well as 1-year limb salvage rates as high as 85% to 90%, and 5-year primary assisted patency rates of 64% whilst not interfering with subsequent vascular surgery. Indeed SIA has not only proved to be very effective in lower limb ischaemia management, both for intermittent claudication and critical ischaemia, but in the last few years it has moved from the shadows and into the limelight of modern endovascular therapy.

The occurrence of arterio-venous fistula during lower limb subintimal angioplasty: treatment and outcome.

OBJECTIVES: To describe our experience with iatrogenic arterio-venous fistula (AVF) occurring during lower limb subintimal angioplasty, their management and the final clinical, radiological outcome. DESIGN: Retrospective review of case series from two centres, from a computerised database over a period of five years. MATERIAL: Twelve patients whose lower limb subintimal angioplasty was complicated by Iatrogenic AVF. RESULTS: The Majority of AVF occurred at the popliteal trifurcation vessels. And the incidence of this complication in our case series was 0.8%. This was managed with a variety of techniques-Coil embolisation, balloon tamponade, alternative dissection and stent placement. In one patient, the fistula was left open intentionally. All twelve patients had a successful angioplasty. The overall technical success rate for AVF ablation was eighty percent. CONCLUSIONS: AVF is a potential complication of angioplasty. The majority can be managed by endovascular means during the angioplasty procedure with good technical success.

Factors affecting patency of subintimal infrainguinal angioplasty in patients with critical lower limb ischemia.

BACKGROUND: Because subintimal angioplasty (SA) is a technique that can achieve recanalization of long arterial occlusions, it is considered an alternative to lower limb bypass operations. The aim of this prospective study was to identify the risk factors that affect patency of SA in patients suffering from critical limb ischemia (CLI). METHODS AND RESULTS: 51 consecutive infrainguinal SA were done in 46 patients suffered from CLI. The patients were followed-up with regular duplex scans up to 12 months post-intervention. Sex, atherosclerosis risk factors, and some technical details of the procedure (number of patent run-off vessels after the procedure, length and re-entry point of angioplasty) were examined as potential risk factors of patency, using survival analysis statistical techniques. The overall patency rate at 12 months post-intervention was 50%. According to Cox-regression analysis, the factors that affect patency were the number of run-off vessels and the length of occlusion. Patients with two or three run-off vessels had a hazard of occlusion of 0.30 (P = .027) compared to those who had one run-off vessel. The 12-months patency in patients with more than one run-off vessels was 81% vs. 25% in patients with one run-off vessel. Regarding the length of angioplasty, the hazard of reocclusion was 1.02 for every centimeter of occlusion (P = .049). CONCLUSIONS: The number of patent run-off crural vessels after the angioplasty and the length of occlusion are significant risk factors for reocclusion of infrainguinal SA in patients with CLI. Trying to recanalize more than one run-off vessels could raise the SA patency.

Cerebral protection during open retrograde angioplasty/stenting of common carotid and innominate artery stenoses.

BACKGROUND: This was a retrospective study of the effectiveness of open, retrograde angioplasty/stenting of supra-aortic arterial stenoses combined with transcranial Doppler-directed dextran therapy in preventing perioperative embolization. METHODS: Eight patients underwent angioplasty/stenting of the proximal common carotid (synchronous carotid endarterectomy (CEA) in six), while four underwent angioplasty/stenting of the innominate artery (synchronous CEA in one). Open exposure of the carotid bifurcation enabled temporary carotid clamping to protect the brain from procedural embolization. Dextran was administered to patients with a high rate of embolization on transcranial Doppler after the operation. RESULTS: No emboli were recorded in the cerebral circulation during the actual angioplasty procedure when the internal carotid artery was clamped. After operation three patients developed high-rate embolization and received dextran. No strokes or deaths occurred within 30 days of treatment. One patient developed symptoms and a recurrent stenosis greater than 50 per cent during follow-up and was treated by redo angioplasty. CONCLUSION: Retrograde angioplasty/stenting with or without synchronous CEA offers an alternative approach to treating patients with supra-aortic inflow disease.

Subintimal angioplasty in lower limb ischaemia.

Subintimal angioplasty has been around for 18 years but has become popular only in the last 2 to 3 years, following a number of publications from various centres in Europe and the USA. After its initial successes in the femoropopliteal segment, the techniques has been extended to the infrapopliteal segment. Recanalization of long tibial occlusions and the possibility of reconstituting the trifurcation has proved to be most useful in the treatment of patients with critical limb ischaemia. Primary success rates of between 80 and 90% can be expected in the infrainguinal and the infrapopliteal segment. Patencies of 64% at 5 years in the superficial femoral artery for claudication has been reported. Limb salvage rates have been consistently high at around 85 to 90% at 1 year. Subintimal angioplasty has proved to be a useful and inexpensive way to treat intermittent claudication. For critical limb ischaemia, it has proved to be very effective.

Techniques for the endovascular management of complications following lower limb percutaneous transluminal angioplasty.

OBJECTIVES: to determine the incidence of early complications following percutaneous transluminal angioplasty and to describe their management and outcome. MATERIALS: five hundred and fifty consecutive patients undergoing angioplasty of 648 limbs, containing 1053 anatomical segments during a two year period were reviewed retrospectively. RESULTS: early complications affected 109 segments (10%) in 92 limbs (14%) of 84 patients (15%). Of the 109 segments affected by early complications, 106 (97%) were managed by endovascular techniques with surgery being required on only three (3%) occasions. There were no deaths attributable to angioplasty. CONCLUSIONS: although early complications occur in 14% of limbs undergoing percutaneous transfemoral angioplasty, the majority (97%) can be managed by endovascular techniques.

Complications following peripheral angioplasty.

BACKGROUND: Peripheral angioplasty is increasingly the first choice intervention in patients with peripheral vascular disease. The aim of the current study was to audit prospectively all major complications, especially the requirement for emergency surgical intervention. PATIENTS AND METHODS: A prospective audit of outcome after peripheral angioplasty in 988 patients undergoing 1377 interventional procedures between 1 October 1995 and 30 September 1998 at which 1619 vessel segments were angioplastied. RESULTS: Major medical morbidity (bronchopneumonia, stroke, renal failure, myocardial infarction) complicated 33/1377 procedures (2.4%). Emergency surgical intervention was required after 31/1377 procedures (2.3%) with the commonest aetiologies being acute limb ischaemia and haemorrhagic complications. The amputation rate following angioplasty was 0.6% and no patient presenting with claudication or graft complications underwent amputation. The amputation rate following angioplasty for critical limb ischaemia was 2.2%. Overall, the risk of death and/or major medical complication and/or requiring emergency surgical intervention was 3.5%. The rate of complications was no different for subintimal as opposed to transluminal angioplasties. CONCLUSIONS: Peripheral angioplasty is associated with a low risk of major medical and surgical complications.

Subintimal angioplasty of native vessels in the management of occluded vascular grafts.

OBJECTIVES: to assess the results of subintimal angioplasty of native vessels in the presence of an occluded vascular bypass graft. DESIGN: retrospective case note review. MATERIALS: twelve patients presenting with symptoms of lower limb ischaemia who had previously undergone infra-inguinal bypass surgery and in whom the bypass graft had occluded. These patients were treated by attempting subintimal angioplasty of the occluded native vessels. RESULTS: there were seven technically successful procedures but after a median follow up of four weeks, only one case had persistent patency of the previously occluded segment. CONCLUSIONS: although subintimal angioplasty of occluded native vessels in the presence of an occluded bypass graft appears attractive, the results are disappointing.

Current status of carotid bifurcation angioplasty and stenting based on a consensus of opinion leaders.

OBJECTIVE: Carotid bifurcation angioplasty and stenting (CBAS) has generated controversy and widely divergent opinions about its current therapeutic role. To resolve differences and establish a unified view of CBAS' present role, a consensus conference of 17 experts, world opinion leaders from five countries, was held on November 21, 1999. METHODS: These 17 participants had previously answered 18 key questions on current CBAS issues. At the conference these 18 questions and participants' answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus, (prevailing opinion), or divided opinion (disagreement). RESULTS: Conference discussion added two modified questions, placing a total of 20 key questions before the participants, representing four specialties (interventional radiology, seven; vascular surgery, six; interventional cardiology, three; neurosurgery, one). It is interesting that consensus was reached on the answers to 11 (55%) of 20 of the questions, and near consensus was reached on answers to 6 (30%) of 20 of the questions. Only with the answers to three (15%) of the questions was there persisting controversy. Moreover, both these differences and areas of agreement crossed specialty lines. Consensus Conclusions: CBAS should not currently undergo widespread practice, which should await results of randomized trials. CBAS is currently appropriate treatment for patients at high risk in experienced centers. CBAS is not generally appropriate for patients at low risk. Neurorescue skills should be available if CBAS is performed. When cerebral protection devices are available, they should be used for CBAS. Adequate stents and technology for performing CBAS currently exist. There were divergent opinions regarding the proportions of patients presently acceptable for CBAS treatment (<5% to 100%, mean 44%) and best treated by CBAS (<3% to 100%, mean 34%). These and other consensus conclusions will help physicians in all specialties deal with CBAS in a rational way rather than by being guided by unsubstantiated claims.