Biomedical subjects
Matthew Matson
Publications and source records attributed to Matthew Matson.
Factors influencing cure by transsphenoidal selective adenomectomy in paediatric Cushing's disease.
OBJECTIVE: Early diagnosis and effective treatment of paediatric Cushing's disease (CD) is necessary to minimise associated morbidity. Accepted first-line treatment is selective transsphenoidal microadenomectomy (TSS), which can be technically difficult, and cure rates vary considerably between centres. In our paediatric CD patient group we have assessed the possible factors which may influence cure by TSS. SUBJECTS AND METHODS: From 1983-2004, 27 paediatric patients (16 males, 11 females; mean age+/-s.d., 13.1+/-3.2 yr; range, 6.4-17.8 yr) with CD were managed in our centre and underwent TSS. Sixteen patients (59%), seven males and nine females (mean age+/-s.d., 14.2+/-2.5 yr; range, 8.2-17.8 yr), were cured (post-operative serum cortisol < 50 nM). Eleven patients, nine males and two females (mean age+/-s.d., 11.5+/-3.6 yr; range, 6.4-17.8 yr) had post-operative cortisol levels above 50 nM (2-20 days), with mean serum cortisol levels at 09:00 h of 537 nM (range 269-900 nM) indicating a lack of cure. These 11 patients received external beam pituitary radiotherapy (RT). One patient with a pituitary macroadenoma had a post-operative cortisol level of < 50 nM but 0.8 yr later showed an elevated cortisol and residual disease. RESULTS: The patients cured by TSS alone were significantly older than those not cured (P = 0.038; Student's t test). All patients had CT/MRI pituitary imaging: 14 were reported to have microadenomas and one macroadenoma, while 12 were reported as normal. Bilateral simultaneous inferior petrosal sinus sampling (BSIPSS) with i.v. corticotropin-releasing hormone (CRH) administration was introduced as a pre-operative investigation in 1986 and was performed in 21 patients (78%), on BSIPSS, 16 (76%) had evidence suggesting pituitary adrenocorticotropic hormone (ACTH) secretion (central to peripheral (IPS:P) ACTH ratio after CRH of > or = 3.0) and 16 (76%) showed lateralisation of ACTH secretion (IPSG of > or = 1.4). There was concordance between the BSIPSS finding and the position of the microadenoma at surgery in 17/21 (81%) patients. Of the 16 patients showing lateralisation of ACTH secretion, 12 (75%) were cured by TSS. Of the four without lateralisation of ACTH, suggesting a midline lesion, 3 (75%) were cured by TSS. Post-operative pituitary hormone deficiencies in the patients cured by TSS were: pan-hypopituitarism 1/16, isolated growth hormone deficiency (GHD) (peak GH on glucagon/ITT < 1-17.9 mU/l) 9/16 and diabetes insipidus 3/16. CONCLUSION: Over a 21-year period selective adenomectomy by TSS cured 59% of all paediatric CD patients, with higher age favouring cure. Introduction of BSIPSS resulted in the demonstration of a high rate of lateralisation of ACTH secretion consistent with the surgical identification of the adenoma, and therefore appears likely to have contributed to the higher surgical cure rate.
Contrast nephropathy in lower limb angiography.
AIM: This study examines the occurrence of contrast nephropathy in a series of 302 consecutive lower limb angiogram and angioplasty procedures. METHODS: Serum creatinine measurements, 1 and 3 days after the procedures, were used to identify cases of contrast nephropathy, defined as a 25% increase above initial creatinine. These cases were reviewed retrospectively. A total of 267 patients had 224 diagnostic, and 78 interventional lower limb angiographic procedures. Of these, 46% had pre-existing renal impairment (creatinine >118 micro mol/l), of whom 11% were on dialysis - dialysis patients were excluded from analysis of changes in creatinine. Repeat creatinine measurements were taken after 191 procedures. RESULTS: Contrast nephropathy occurred after 15 procedures: of whom 9 died, and 6 recovered. Of these patients, 11 were taking potentially nephrotoxic drugs and 9 had renal impairment. Precautions to avoid contrast nephropathy were taken in only 2 cases. Of the 9 deaths, 6 were associated with severe underlying disease processes, but 3 occurred directly as a result of contrast nephropathy. Contrast nephropathy has an incidence of 8% in this series: the incidence in acute limb-threatening ischaemia is double that for other cases. Death from renal failure is relatively rare, with an incidence of 1%. In uncomplicated angiography or angioplasty, where admission is not prolonged by a need for further treatment, the condition has no mortality. CONCLUSIONS: Accepted precautionary measures should be observed, and alternatives to conventional angiography should be considered - particularly where there is pre-existing renal impairment and other co-morbidity.
Renal artery dissection after blunt abdominal trauma: a rare cause of acute cortical necrosis.
Renal artery injury is an uncommon complication of blunt abdominal trauma. We present a case of a 19-year-old man who developed acute cortical necrosis in a congenital single kidney after a motorcycle accident. On initial presentation, he had signs of splenic injury and required immediate laparotomy and splenectomy. His renal function deteriorated, and he became dialysis dependent. Computed tomography followed by percutaneous angiography showed a dissection of a single renal artery causing the formation of a large pseudoaneurysm. A second angiogram showed an increase in the size of the pseudoaneurysm. We performed a laparotomy and attempted in situ vein graft repair of the renal artery. A wedge biopsy specimen taken at laparotomy revealed acute cortical necrosis, and plain radiographs showed cortical calcification. Renal artery dissection and pseudoaneurysm formation are rare events after blunt trauma. Iatrogenic damage is the most common cause of pseudoaneurysm. Traumatic pseudoaneurysms have a poor prognosis without prompt surgical intervention. Renal arterial damage may occur after blunt trauma, and early imaging and intervention are essential to salvage renal function.
Mechanical thrombectomy of occluded hemodialysis native fistulas and grafts using a hydrodynamic thrombectomy catheter: preliminary experience.
The purpose of this study was to evaluate the efficacy and safety of a new hydrodynamic percutaneous thrombectomy catheter in the treatment of thrombosed hemodialysis fistulas and grafts. Twenty-two patients (median age: 47 years; range: 31-79 years) underwent mechanical thrombectomy for thrombosed hemodialysis fistulas or polytetrafluoroethylene (PTFE) grafts. In all cases, an Oasis hydrodynamic catheter was used. Five patients had native fistulas and 17 had PTFE grafts. Six patients required repeat procedures. All patients with native fistulas and 15 of the 17 with PTFE grafts also underwent angioplasty of the venous limb following the thrombectomy. Major outcome measures included technical success, clinical success, primary and secondary patency, and complication rates. Twenty-eight procedures were performed in total. The technical success rate was 100% and 90% and clinical success was 86% and 76% for native fistulas and grafts, respectively. The primary patency at 6 months was 50% and 59% for fistulas and grafts, respectively, and the secondary patency at 6 months was 75% and 70% for fistulas and grafts, respectively. Two patients died of unrelated causes during the follow-up period. The Oasis catheter is an effective mechanical device for the percutaneous treatment of thrombosed hemodialysis access. Our initial success rate showed that the technique is safe in the treatment of both native fistulas and grafts.