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4.3 Vascular and Peritoneal Access 4.3.1 Background Historically vascular and peritoneal access operations were most often provided by transplant teams and sometimes urologists in regional centres. However, the number of surgeons involved in transplantation did not keep pace with the requirement for access surgery save in a few centres. Junior staff, by default, often became the major source of surgical expertise, with limited training and consultant support. As dialysis was decentralised into District General Hospitals (DGH's), the need for access surgery was often underestimated. If local surgeons took on the responsibility, it would often be on a 'grace and favour' basis with no provisions for extra theatre time or sessional commitments. Also, although many DGH's had vascular surgical services, these surgeons were often not experienced in access for HD or PD and were reluctant to take on the extra commitment. 4.3.2 Interfacing Requirements to Available Specialities Combined renal/transplant units (autonomous transplanting centres) have the option for vascular access services to be provided by transplant surgeons. However, there are currently an insufficient number of transplant surgeons and vascular access in this setting is often poorly provided. Rationalisation to fewer, larger centres may provide the scope for more comprehensive support in these units but at the same time may leave those centres which lose transplantation vulnerable with respect to renal access support. Vascular surgeons have provided valuable renal access support over the years but their involvement has been patchy, partly because there were alternatives. As the speciality of vascular surgery develops, it is inevitable that renal services will look in the direction of this specialty for support. Following a number of approaches from personnel involved in renal transplantation the Council of the Vascular Surgical Society of Great Britain and Ireland (VSSGBI) circulated the following position statement in their June 2000 Newsletter: "The VSSGBI supports and encourages training in renal access work and its performance by consultant vascular surgeons. Not all trainees or vascular surgeons will aspire to these skills but the Society strongly endorses this area of work for vascular surgeons, recognising that there is an important need." It is likely that vascular surgeons working in large departments will be best fitted to provide renal support in the future provided the work is pooled rather than concentrated on one individual. Departments must be provided with enough theatre lists dedicated to renal support and have formal Service Level Agreements (SLA's). The Job Plan of replacement or additional vascular surgeons should ideally include renal support as a core element. The surgical trainees in these departments should receive dedicated training in vascular and peritoneal access. To achieve these aims, discussions need to continue between Specialist Advisory Committees of the Royal Colleges (SACs), the Specialist Workforce Advisory Group (SWAG) and Postgraduate Deans (see Appendix III). The recently published Health Technology Assessment (HTA) document 'Cost and Outcome Implications of the Organisation of Vascular Services' usefully deals with linkages between vascular surgeons and other services including renal (ref.75). In some centres, general surgeons and other surgical sub-specialities have provided support for renal services often on a single-handed basis. There will always be a need for local solutions to the problems of access provision. Interventional radiology has taken great strides in the last twenty years and a sub-group of radiologists now provide expertise in angiography, angioplasty (including stenting) and thrombolysis all of which are needed for renal support. Interventions with fistulae are often preceded by radiological imaging and the advantages are obvious when radiologists themselves can proceed to angioplasty or the insertion of central lines. Radiology departments however are all working to capacity with demands exceeding their ability to provide. Planned and fully resourced expansion of radiology departments will be required if they are to provide renal support. 4.3.3 Outreach Provision of Expertise The provision of outreach services in the context of Managed Clinical Networks may be relevant to the planning of renal surgical support (Section 5.8). There are precedents for visiting surgeons successfully providing vascular and peritoneal access services to renal centres without the expertise being available on site. Some visiting surgeons also attend assessment clinics where complex patients can be seen with their X-Rays to discuss the most appropriate operation. These arrangements similarly require dedicated theatre and anaesthetic time. 4.3.4 Service Level Agreements (SLA's) While individual units may audit and keep records of renal access procedures this information is not regularly pooled and there are no firm data on which to make recommendations about SLA's. However, in a busy autonomous renal unit serving 1 million population supporting 330 dialysis patients with an HD:PD ratio of 2:1 there is currently an annual demand for over 300 operations. Sometimes more than one procedure is carried out at each sitting. In 99/00 106 arteriovenous fistulae, 53 PD catheter insertions and 143 permanent central venous access lines were required (Greenwood R - personal communication). This service is provided by a local general surgeon, the local vascular surgery department and visiting transplant surgeons. The work occupies two theatre sessions per week backed up by 37 'emergency' theatre lists per annum. In a detailed analysis of workload in South Wales, Yorkshire and Newcastle (Appendix IV), it was estimated that for a population of 1 million there would be a requirement for 100 arteriovenous fistulae, 50 PD catheter insertions and 100 permanent central venous access line insertions per annum. The similarity of these figures would suggest that one theatre session will be necessary for approximately 120 patients on the dialysis programme. While some nephrologists retain skills in bedside insertion of catheters for PD and HD, their contribution is unlikely to affect greatly the level of demand for theatre based surgery as detailed above. 4.3.5 Quality Issues and Audit The preferred access in any HD patient is a native AVF which produces the highest flows, minimises sepsis and has the greatest longevity. The ideal would be that all HD patients have natural AVF's but all renal units fall short of this. Unfortunately so many veins have been damaged by blood sampling or cannulation that less than 50% are suitable for AVF's. Thus whilst 70% of AVF's are created at the wrists, no more than 50% are successful. While 30% can go on to have successful access at the elbow, 20% will be dependent on intravenous plastic cannulae tunnelled under the skin or PTFE tubing (grafts) inserted under the skin (Bakran A - personal communication). The availability of temporary and 'permanent' tunnelled cannulae for urgent venous access has been one of the factors leading to the liberalisation of acceptance of patients for dialysis. Their use in sick patients and in patients presenting late with ESRF, however, has had a negative impact on the number of natural AVF's. Since the life of tunnel catheters is less than natural AVF's, more repeat operations than in the past are inevitable. The numbers of temporary and tunnelled lines is often symptomatic of congestion in a service with inadequate surgical support. Perhaps not surprisingly the UK is lagging behind most of the large European countries with regard to the proportion of HD patients using natural AVF's. The Dialysis Outcomes and Practice Patterns Study (DOPPS) is a longitudinal study, currently ongoing, of haemodialysis patients in the USA, Japan and five European countries (UK, Germany, France, Italy and Spain) (ref.76). After two years data collection in one hundred facilities throughout Europe, results show that for relevant patients, 67% in the UK have functioning AVF's (ref.77). The figures for France, Germany, Italy and Spain are 77%, 84%, 90% and 82% respectively. The European (DOPPS countries) average is 80%. 47% of UK patients start haemodialysis with a functioning AVF, the majority of the remainder starting using tunnelled catheters. The percentages of patients starting HD with an AVF in France, Germany, Italy and Spain are 62%, 83%, 60% and 71% respectively. The European (DOPPS countries) average is 66%. One of the aims for future organisation of renal services should be to remedy this poor UK performance. Access operations should be carried out in a timely fashion to avoid emergency procedures in planned patients. The prevalence of AVF's and the number of planned patients who start dialysis with permanent access should be audited since their levels reflect the efficiency and effectiveness of the renal service. Link to National Service Standard 3  |