Minutes of the Liverpool Society of Anaesthetists Meeting
15th Novemeber 2013
‘Anaesthesia for Separation of Conjoined Twins’
Dr Ann Black, GOSH, London
The meeting was opened by the President of the Society, Dr Janice Fazakerley, who asked all those members attending to have a period of silent reflection in recognition of the sad passing of Dr Peter Booker. She said she thought that this was an appropriate meeting for this tribute to happen, as many of his former colleagues were present.
Dr Fazakerley then introduced the speaker, Dr Ann Black, consultant paediatric anaesthetist from Great Ormond Street Hospital, London. Dr Black started her talk by describing the first set of conjoined twins whom she had met as a registrar in 1987. They were successfully separated and she showed a recent picture of them. These twins were the first in a personal series of twelve to date.
Dr Black then looked at the long history of conjoined twins, with perhaps the most famous being Chang and Eng Bunker who lived from 1811 to 1874 and were a regular feature of the touring Barnum Circus. Conjoined twins occurred with an incidence of between 1:50-100,000 pregnancies. 60% of these twins die perinatally, and the incidence of live births is approximately 1:200,000, with a ratio of 3 females to every male.
Dr Black described where twins were most commonly joined, with 40% at the chest (thoracopagus), 32% at the abdomen (omphalopagus), 19% at the pelvis (pyopagus) and 2% joined at the head (craniopagus). She described the circumstances were anaesthesia may be required for these twins. This may be as part of the work up for ultimate separation, in particular for imaging; for separation of the twins, and finally if separation is not possible, then for any routine procedures during their lives.
Dr Black looked at the experience at Great Ormond Street up to 2002, which had been laid out in a paper by Spitz and Kiely (BJS 2002, 89, 1188-1192). This had looked at seventeen sets of twins, of which five did not undergo surgery. Seven sets underwent emergency surgery, of which only four infants survived. Finally, five sets had elective surgery for separation of which eight babies survived. The optimal management of these twins is delivery by Caesarean Section, transfer to a paediatric centre, and planned for surgery at about 3 months of age. The experience to date was of thirty five twins, of which twenty four had undergone surgery.
Dr Black talked about the process of planning of surgery for separation. This started in the antenatal period with the parents and continued postpartum with investigation and preparation for a timely separation and any further surgery which may subsequently be required. Planning is vital and Dr Black gave the example of thoracopagus twins. 90% of these twins will share some pericardium and some may have intra-cardiac abnormalities, which are usually associated with a poor outcome. Therefore thorough investigation and preparation is vital for successful surgery.
Dr Black looked at the vast numbers of people that are required when undertaking this type of surgery because these operations can take many hours with several different teams of surgeons, as well as all the other multiple support staff. She stressed the importance of having an anaesthetic plan which could be generated by attending the general planning meetings, picking a suitable team and discussing details pre-operatively. This included who exactly was looking after which twin, and the order of things to be done. She looked at the particular issues of administering anaesthesia to conjoined twins which required two anaesthetic teams in a very confined work space. Because two sets of all equipment are needed, colour coding was often used to designate for which twin a particular piece of equipment was being used. The particular problems of this type of surgery included the risk of massive blood loss and prolonged anaesthesia. She stressed the importance of proper preparation, pacing and communication for a successful day and night in the operating theatre. She also commented about the interest, not only within the hospital, but also with a wider audience such as the press and how this was managed at Great Ormond Street.
In the final section, she looked at some cases in which she had taken part. The first case involved moving the whole team to Dubai to separate ischiopagus twins which had a successful outcome. The next case was about the management of craniopagus twins who required a three stage operation to separate the various parts of the skull and used tissue expanders to ensure sufficient skin cover. The main challenge with these children was to prevent rises in intracranial pressure postoperatively because of issues with venous drainage when surgery is performed in one stage.
Dr Black concluded her talk by saying that these are always challenging cases that required clear planning and excellent communication between multi-disciplinary teams which led to good outcomes in many.
The vote of thanks was given by Dr Nive Kelgeri, consultant anaesthetist from Alder Hey Hospital. The meeting concluded at 8.15 pm.
Liverpool Society of Anaesthetists
26th November 2013