A number of vascular complaints may be amenable to treatment by minimally invasive or interventional radiological procedures, and Dr Chu can offer this option to you if it is appropriate and safe to do so. Minimally invasive treatments offer the advantage of reduced hospital stay (ranging from day case to 2-3 days), no big wounds (most are performed through a skin puncture [“percutaneously”] with a needle) and therefore quicker return to work and normal activities, and most can be performed with a local anaesthetic.
The disadvantage of these procedures in general is that long term results aren’t as good as open surgery so that re-intervention rate is usually higher. But this can usually be achieved with a repeat percutaneous intervention, and if there is a complication from the minimally invasive procedure or the latter is no longer possible, then open surgery can be considered. Dr Chu can expeditiously and skilfully offer both options when required.
Interventional procedures are performed under Xray image guidance in a specially equipped and stocked catheter laboratory or angiogsuite. A special dye – radiocontrast, containing iodine, is injected into the artery to outline the blood vessel. This procedure is called an angiogram. If the angiogram identifies a narrowing or blockage in the artery, if appropriate, Dr Chu may cross the lesion and open it up with a balloon catheter (“balloon angioplasty”). If there is residual narrowing or re-coil after balloon angioplasty, a metallic strut (“stent”) may be required to keep the artery open.
The radiocontrast dye can cause allergic reactions – particularly if you have a past history of iodine allergy, and also damage the kidneys particularly if you are diabetic, have underlying kidney disease or dehydration. Dr Chu should be informed if you have any of these pre-existing problems or history of iodine (or contrast) allergy so that certain precautions can be undertaken prior to the angiogram. Other potential complications from interventional procedures include bleeding from the puncture site, perforation of blood vessels, blockage of downstream blood vessels, and infection at the puncture site. Overall rate of complications is less than 1%. Amputation risk from interventional procedures is estimated to be less than one in 3000.
CAROTID ANGIOPLASTY & STENT
An alternative to open surgery for stroke prevention (carotid endarterectomy) is the minimally invasive option of carotid angioplasty and stenting. This involves a local anaesthetic and sedation, angiogram of the carotid artery through an arterial puncture in the groin, then ballooning and stenting of the narrowing in the carotid artery in the neck. A filter or capture device (“cerebral protection device”) is used upstream from the point of ballooning to capture any particulate material released from the narrowing, preventing them from travelling to the brain and causing a stroke. Patients are usually discharged the following day on a strong aspirin equivalent called clopidogrel to keep the blood thin. Side effects and risks are similar for all angiograms, except that procedure-related stroke is a specific risk.
Current trial results comparing open surgery with angioplasty and stenting for stroke prevention have demonstrated that open surgery is a safer option in terms of lower stroke and death risk. The minimally invasive option is therefore reserved for exceptional circumstances where surgery is considered to be difficult or dangerous. This includes re-narrowing of a previously operated artery, a narrowing very high in the neck, if there has been previous radiation therapy in the neck, or if you have very severe heart disease making anaesthesia for surgery hazardous.
REPAIR OF AORTIC ANEURYSM
Aortic aneurysms needing repair due to size or symptoms, may undergo open repair or if suitable, a minimally invasive repair – endoluminal stent graft repair. The latter technique requires a suitable anatomy for the stent graft to be successful, and this is determined by Dr Chu based on a detailed CT scan of the abdomen.
At least 70% of all aortic aneurysms are suitable for this repair. The graft is typically composed of three overlapping pieces, introduced via the arteries in the groin, and deployed under Xray guidance. The graft has a metal skeleton covered with an impervious synthetic lining, which forms the new channel for blood to flow through once deployed inside the aneurysm. This then depressurises the aneurysm and reduces the risk of the weakened walls from rupturing to less than 1%.
The procedure carries all the risks associated with an angiogram and angioplasty, but also risk of stent graft infection, and in 10-20% of people, a further intervention is required on follow-up to maintain a seal of the stent graft and keep the aneurysm sac depressurised. About 1% of patients may require conversion to the open operation.
Compared to open surgical repair of an aortic aneurysm, the endoluminal stent graft technique has significantly reduced hospital stay (3-5 days compared to 7-10 days), significantly less need for transfusion and intensive care admission, quicker recovery overall (2-3 weeks compared to 2-3 months), and reduced peri-procedural death and heart attacks.
In males there is no risk to potency with the stent graft repair. On the other hand, you must be prepared to continue with lifelong follow-up of the graft due to the need for re-intervention and very small risk of rupture.