Postoperative complications and waiting time for surgical intervention after radiologically guided drainage of intra-abdominal abscess in patients with Crohn's disease.

BACKGROUND: In patients with active Crohn's disease (CD), treatment of intra-abdominal abscess usually comprises antibiotics and radiologically guided percutaneous drainage (PD) preceding surgery. The aim of this study was to investigate the risk of postoperative complications and identify the optimal time interval for surgical intervention after PD. METHODS: A multicentre, international, retrospective cohort study was carried out. Details of patients with diagnosis of CD who underwent ultrasonography- or CT-guided PD were retrieved from hospital records using international classification of disease (ICD-10) diagnosis code for CD combined with procedure code for PD. Clinical variables were retrieved and the following outcomes were measured: 30-day postoperative overall complications, intra-abdominal septic complications, unplanned intraoperative adverse events, surgical-site infections, sepsis and pathological postoperative ileus, in addition to abscess recurrence. Patients were categorized into three groups according to the length of the interval from PD to surgery (1-14 days, 15-30 days and more than 30 days) for comparison of outcomes. RESULTS: The cohort comprised 335 CD patients with PD followed by surgery. Median age was 33 (i.q.r. 24-44) years, 152 (45.4 per cent) were females, and median disease duration was 9 (i.q.r. 3.6-15) years. Overall, the 30-day postoperative complications rate was 32.2 per cent and the mortality rate was 1.5 per cent. After adjustment for co-variables, older age (odds ratio 1.03 (95 per cent c.i. 1.01 to 1.06), P < 0.012), residual abscess after PD (odds ratio 0.374 (95 per cent c.i. 0.19 to 0.74), P < 0.014), smoking (odds ratio 1.89 (95 per cent c.i. 1.01 to 3.53), P = 0.049) and low serum albumin concentration (odds ratio 0.921 (95 per cent c.i. 0.89 to 0.96), P < 0.001) were associated with higher rates of postoperative complications. A short waiting interval, less than 2 weeks after PD, was associated with a high incidence of abscess recurrence (odds ratio 0.59 (95 per cent c.i. 0.36 to 0.96), P = 0.042). CONCLUSION: Smoking, low serum albumin concentration and older age were significantly associated with postoperative complications. An interval of at least 2 weeks after successful PD correlated with reduced risk of abscess recurrence.

[In vitro study with techniques of imaging of the composition of urinary calculi]. / Estudio in vitro mediante técnicas de imagen de la composición de los cálculos urinarios.

Pre-treatment knowledge of the lithiasic composition can be useful to design the most appropriate therapeutic scheme for each kind of stone. The relationship between the stone's densitometry information provided by the different imaging techniques, conventional radiology (RX), computerized axial tomography (CAT) and dual energy radiographic densitometry (DO) is analyzed, as well as the elemental composition determined by the microanalysis of fragments obtained post-lithotrity using a scanning electronic microscope (SEM) associated to X-ray dispersion energy (XDE). 60 stones, 12 for each pure composition selected (calcium oxalate mono and dihydro, phosphocarbonate, magnesium ammonium phosphate and uric acid), were studied with XR, CAT and DO and were later subjected to lithofragmentation in vitro. Fragments analysis was carried out post-lithotrity with SEM associated to XDE. The X-ray does not allow to establish the composition of some calculi. CAT quantifies the mineral contents of the oxalocalcic and infective calculi and differentiates the uric acid from the other compositions because the mean density values are under 500 Hounsfield Units. DO evaluates the lithiasic content in phosphocarbonate salts which are structurally similar to bone hydroxyapatite.

[Extracorporeal lithofragmentation and of direct contact. Development of mathematical models for calculating the energy and predicting the fragmentation]. / Litofragmentación extracorpórea y de contacto directo. Desarrollo de modelos matemáticos para el cálculo de la energía y la predicción de la fragmentación.

The present experimental 'in vitro' study pursues the development of mathematical equations which, prior to lithofragmentation, would allow to estimate the amount of energy required and to predict the degree of fragmentation for each of the different sources of energy. A total of 114 calculi with 6 different compositions were analyzed by conventional X-rays (Rx), computerized axial tomography (CT) and dual X-ray densitometry (DO). Calculi were then fragmented using 4 different types of energy: electrohydraulic (LEH), piezoelectric (LEP), ultrasounds (US) and pulse laser (LAS). The correlation between imaging techniques parameters on the one side, and the amount of energy used and degree of fragmentation obtained on the other one, allow with a multiple linear regression analysis, both to develop mathematical equations to estimate the amount of energy required, and to predict the fragmentation rate.

[Comparative analysis of lithiasic fragmentation induced by extracorporeal and direct contact sources]. / Análisis comparativo de la fragmentación litiásica inducida por las fuentes extracorpóreas y de contacto directo.

An in vitro experimental study on stone fragmentation was conducted on 114 calculi analyzed by infrared spectrophotometry. Four energy sources were utilized: electrohydraulic, piezoelectric, ultrasound and pulsed laser. We analyzed stone susceptibility to fragmentation (particles < 3 mm), pulverization (particles < 1 mm) and stone fragility (amount of energy/mg of calculus fragmented into particles < 3 mm) for each type of energy source of each of the following 6 stone compositions: calcium oxalate monohydrate, calcium oxalate dihydrate, magnesium ammonium phosphate, phosphate carbonate, uric acid and phosphate oxalate. The calcium oxalate dihydrate calculi were the most susceptible to fragmentation and the infective calculi (magnesium ammonium phosphate and phosphate carbonate) were the most susceptible to pulverization. The piezoelectric energy showed the highest capacity for fragmentation and pulverization of calculi. Stone fragility depended on each stone type and the energy source utilized.

[The usefulness of dual-energy radiographic densitometry (DO) in establishing the composition of calculi]. / Utilidad de la densitometría radiográfica de energía dual (DO) en el establecimiento de la composición litiásica.

Dual-energy radiographic bone densitometry is utilized to determine the bone mineral content in patients with osteoporosis. The present in vitro experimental study investigated the usefulness of densitometry in determining stone composition and in evaluating the mineral and non mineral phases of the calculus. For the study we analyzed 114 calculi of 6 different chemical composition (calcium oxalate monohydrate, calcium oxalate dihydrate, magnesium ammonium phosphate, phosphate carbonate, uric acid and phosphate oxalate). The phosphate carbonate calculi had the highest mineral density, whereas the uric acid calculi had the lowest and contained more water. Although densitometry appears to be of little value in determining stone composition, it provides information on the mineral and non mineral phases of the calculus.