Data were submitted by haematologists from 63 hospitals. The total number of procedures reported was 19 259, comprising 13 147 combined procedures and 6112 aspirates. The number of procedures for each hospital for each year varied from 65 to 1567, with a mean of 306 and a median of 216. The percentage of patients having a trephine biopsy varied widely, from 12% to 100%, with a median of 67% and a mean of 68%.
In total, 16 adverse events were reported, representing 0.08% of all reported procedures. The adverse events were largely haemorrhage (11), with other complications being infection (two), persistent pain (two), and a serous leak persisting for six days in a patient with non-Hodgkin lymphoma and nephrotic syndrome. One of the patients who suffered haemorrhage also had reduced mobility for four weeks and persisting pain for two months. There were three very serious events, all haemorrhagic in nature.
The bleeding episodes occurred particularly among those patients who had undergone a combined procedure, with only one of 11 instances occurring after an iliac crest aspiration alone. The haemorrhage was into the buttock and thigh in three patients, retroperitoneal in two, and not specified in six. Ten of 11 patients had risk factors for haemorrhage, often multiple. These are summarised and compared with previous years in table 1.
Table 1 Risk factors for haemorrhage in patients who bled
The three very serious events are described in detail. An obese patient with essential thrombocythaemia who was on warfarin for a mechanical prosthetic valve had had an international normalised ratio of 3.5 five days before the procedure; this was not re-checked on the day of a combined aspirate and trephine biopsy. Five days after the procedure he reported that he could not walk. He was found to have a haemorrhage into his thigh and buttock, with an associated fall of haemoglobin concentration from 150 to 101 g/litre. His international normalised ratio was 9.9 (he had been taking paracetamol and other analgesics). He was not transfused but required five days of hospitalisation. A second patient had pain in the hip immediately after a combined procedure on the right posterior iliac crest. The pain persisted for three days and then spread to the right iliac fossa. She became acutely unwell, and was admitted to a high dependency unit with a retroperitoneal haemorrhage being shown on a computed tomography scan. She required inotrope and other circulatory support and high flow oxygen, but made a slow recovery without surgical intervention. Other than the diagnosis of a myeloproliferative disorder (MPD), there were no identifiable risk factors in this patient. The third very serious event was a retroperitoneal haemorrhage in a patient with no risk factors other than a diagnosis of chronic phase of chronic myeloid leukaemia. This haemorrhage led to blood transfusion, surgical drainage, postoperative ventilatory support and 11 days of hospitalisation, with slow wound healing over three to four weeks.
In addition to the three patients regarded as having suffered a very serious event, there were two patients with haemorrhage who required transfusion of red blood cells (one of whom had blood tracking down to the ankle with a 20 g/litre fall in haemoglobin concentration) and two who required platelet transfusion. Two of these patients had a hospital stay prolonged by one or two days.
In comparison with the haemorrhagic episodes, other complications were less serious. Two patients had persistent pain for several weeks. Two others, one with acute myeloid leukaemia (AML) and one with a poor prognosis myelodysplastic syndrome, developed local infection that responded readily to treatment. The patient with AML was obese and the procedure was difficult. The patient with nephrotic syndrome who suffered a serous leak required six days of hospitalisation with pressure dressings.
During 2003, in contrast to earlier years, there were no adverse events relating to breaking of needles.
In previous years, data have suggested that adverse events may be somewhat more likely with less experienced operators. This was not substantiated by the current data. Only a single procedure of the 11 biopsies that were followed by haemorrhage had been carried out by a senior house officer and that person had had a year’s experience. Most were carried out by staff grade or consultant haematologists who had had 10 to 20 years experience, and in some cases had performed more than a thousand procedures.