Automatic preoperative 3d model registration in laparoscopic liver resection.

PURPOSE: : Augmented Reality (AR) in Laparoscopic Liver Resection requires anatomical landmarks and the silhouette to be found on the laparoscopic image. They are used to register the preoperative 3D model obtained from CT segmentation. The existing AR systems rely on the surgeon to 1) annotate the landmarks and silhouette and 2) provide an initial registration. These non-trivial tasks require surgeon attention which may perturb the procedure. We propose methods to solve both tasks, hence registration, automatically. METHODS: : The landmarks are the lower ridge and the falciform ligament. We solve 1) by training a U-Net from a new dataset of 1415 labelled images extracted from 68 procedures. We solve 2) by a novel automatic coarse-to-fine pose estimation method, including visibility-reasoning within an iterative robust process. In addition, we propose to divide the ridge into six anatomical sub-parts, making its annotation and use in registration more accurate. RESULTS: : Our method detects the silhouette with an error equivalent to an experienced surgeon. It detects the ridge and ligament with higher errors owing to under-detection. Nonetheless, our method successfully initialises the registration with tumour target registration errors of 22.4, 14.8 and 7.2 mm for 3 clinical procedures. In comparison, the errors from manual initialisation are 30.5, 15.1 and 16.3 mm. CONCLUSION: : Our results are promising, suggesting that we have found an appropriate methodological approach.

Influence of the echocardiographic score and not of the previous surgical mitral commissurotomy on the outcome of percutaneous mitral balloon valvuloplasty.

OBJECTIVE: To evaluate prior mitral surgical commissurotomy and echocardiographic score influence on the outcomes and complications of percutaneous mitral balloon valvuloplasty. METHODS: We performed 459 complete mitral valvuloplasty procedures. Four hundred thirteen were primary valvuloplasty and 46 were in patients who had undergone prior surgical commissurotomy. The prior commissurotomy group was older, had higher echo scores, and a tendency toward a higher percentage of atrial fibrillation. RESULTS: When the groups were compared with each other, no differences were found in pre- and postprocedure mean pulmonary artery pressure, mean mitral gradient, mitral valve area, and mitral regurgitation. Because we found no significant differences, we subdivided the entire group based on echo scores, those with echo scores < or =8 and those with echo scores >8 the mitral valve area being higher in the < or =8 echo score group 2.06+/-0.42 versus 1.90+/-0.40 cm2 (p=0.0090) in the >8 echo score group. CONCLUSION: Dividing the groups based on echo score revealed that the higher echo score group had smaller mitral valve areas postvalvuloplasty.

[Epidemiology of end-stage kidney failure in the Ile-de-France: a prospective cooperative study in 1998]. / Epidémiologie de l'insuffisance rénale terminale en Ile-de-France: enquête coopérative prospective en 1998.

A prospective epidemiological study was conducted from January 1 to December 31, 1998 in the Ile-de-France district to determine the incidence and the prevalence of end-stage renal disease (ESRD) and the characteristics of the patients. All nephrology and dialysis units of the Ile-de-France district participated in the study. The total number of ESRD patients requiring maintenance dialysis was 1155 (including 86 kidney graft failures and 29 children) for a total population of 10.7 millions inhabitants, or 108/10(6)/year. The incidence of new ESRD patients was 100/10(6)/year. The mean age of first-dialyzed, adult patients was 59.8 +/- 16.8 years, with 21.6% aged > or = 75 years. Vascular renal diseases accounted for 22.5% and diabetic nephropathy for 20.6%. As a whole, 36.5% of patients were referred to the nephrologist less than 6 months before starting dialysis. In the latter, the median duration of hospitalization was 28 days, compared to only 3 days in patients cared for by the nephrologist for at least 6 months. Prevalence of patients on maintenance dialysis in the Ile-de-France district grew from 417 to 433/10(6) from the beginning until the end of year 1998, an increment of 3.8%, with an increase in the number of patients treated out-center by self-care hemodialysis or peritoneal dialysis.

Epidemiology of end-stage renal disease in the Ile-de-France area: a prospective study in 1998.

BACKGROUND: The objective of this study was to determine the incidence and prevalence of end-stage renal disease (ESRD) requiring maintenance dialysis in the Ile-de-France district (Paris area), and the characteristics of patients at start of dialysis. METHODS: This is a prospective epidemiological study with the cooperation of all dialysis facilities of the Ile-de-France district (population 10.7 million inhabitants as of March 1999). All consecutive ESRD patients who started dialysis from January 1 to December 31 1998, with demographic and clinical characteristics, and of the total number of patients on dialysis with their distribution according to dialysis modality were recorded. RESULTS: The total number of ESRD patients in 1998 was 1155, including 29 (2.5%) children aged < or =17 years and 86 (7.4%) returns to dialysis following kidney graft failure. Incidence of first-dialysed patients was 100 per million population (p.m.p.) and overall incidence, including returns from transplantation, was 108 p.m.p. The mean age of first-dialysed adult patients was 59.8+/-16.8 years, with 21.6% aged > or =75 years. Patients with vascular renal disease were 22.5% and those with diabetic nephropathy 20.6%. As a whole, 36.5% of patients were referred to the nephrologist < or =6 months before start of dialysis, including 32.2% referred < or =1 month before starting. Prevalence of cardiovascular disease was nearly twice as high in patients referred <6 months of starting dialysis than in those who benefited from effective nephrological care for >3 years in the predialysis period. By multivariate analysis, this difference persisted after adjustment for age and other confounding covariates. The total number of patients on maintenance dialysis increased from 417 to 433 p.m.p. (a yearly 3.8% increase) from the beginning to the end of 1998. CONCLUSION: This recent epidemiological study in a large French urban area indicates an annual incidence of 100 new ESRD patients p. m.p., with a high proportion of older, vascular and diabetic patients. Overall incidence, including returns from transplantation, reached 108 p.m.p. Cardiovascular disease was significantly less frequent in patients who received nephrological care for > or =3 years prior to start of dialysis than in late referred patients, underlining the benefits of early nephrological management of renal patients.

[Incidence of end-stage renal disease in Ile de France: a prospective epidemiological survey]. / Incidence de l'insuffisance rénale terminale en Ile de France: enquête épidémiologique prospective.

OBJECTIVES: To evaluate incidence and prevalence of patients with end-stage renal disease (ESRD) treated with maintenance dialysis in the Ile de France district in 1998. METHODOLOGY: Prospective epidemiologic inquiry with the cooperation of the 91 nephrology departments and dialysis facilities of the Ile de France district (total population: 10,695,300 inhabitants in March 1999), from January 1st to December 31st, 1998. Evaluation of the demographic and clinical characteristics of the 1155 patients accepted on maintenance dialysis in 1998, and recording of the total number of dialyzed patients at the beginning and at the end of the same year. RESULTS: The total number of ESRD patients was 1155, including 29 (2.5%) children aged < or = 17 years and 86 (7.4%) returns to dialysis following kidney graft failure. Incidence of ESRD in first-dialyzed patients was 100/million/year and overall incidence, including returns from transplantation, was 108/million/year. Mean age of the 1040 adult first-dialysis patients was 59 +/- 16.8 years, with a proportion of those aged > or = 75 years of 21.6%. Patients with vascular renal disease were 22.5% and those with diabetic nephropathy 20.6%. As a whole, 36.5% of patients were referred to the nephrologist < 6 months of starting dialysis. Prevalence of patients on supportive dialysis increased from 417 to 433 per million inhabitants (a 3.8% increase) from the beginning to the end of 1998, with the proportion of patients treated with self-care dialysis or peritoneal dialysis rising by 10%. From January 1995 to January 1999, prevalence of dialysis-treated ESRD patients rose by nearly 4% per year as a mean. CONCLUSION: Incidence of ESRD patients requiring maintenance dialysis in the Ile de France district reached 100/million in 1998, an increment of 4% per year over the past 4 years. The increase in incidence results from the increasing number of older patients, parallel to the ageing of general population, these patients having a high comorbidity mainly due to diabetes and atherosclerosis. Prevalence of dialysis-treated patients was 433/million population at the end of 1998. It rose at a similar rate as did incidence, although with a growing proportion of out-center dialysis.

Incidence of atherosclerotic arterial occlusive accidents in predialysis and dialysis patients: a multicentric study in the Ile de France district.

BACKGROUND: An abnormally high mortality from atherosclerotic cardiovascular (CV) accidents has long been reported in patients on maintenance haemodialysis (HD). However, incidence of atherosclerotic CV accidents had not been so far assessed in predialysis patients. In order to evaluate the respective influence of uraemia and the dialysis procedure, we compared incidence of atherosclerotic accidents before and after initiation of HD in a large population of patients. STUDY DESIGN: A total of 748 patients (411 male) were included in a retrospective study based on anamnestic data of patients living on maintenance haemodialysis in March 1993 in nine dialysis units of the Paris area. Incidence of first myocardial infarction (MI) or cerebral infarction (CI) was calculated by reference to the number of years of exposure to the risk both before and after initiation of HD in the various age groups. RESULTS: Overall, 103 first atherosclerotic accidents were recorded, including 10 CI (7 in males) and 93 MI (68 in males). Of the latter, 39 occurred before and 54 after start of HD, at a mean (+/-SD) age of 62.4+/-9.9 and 63.7+/-11.1 years respectively. The annual incidence of MI in males was 8.0, 19.5 and 28.3/1000 patient-years, before and 18.8, 21.6 and 29.9 patient-years after start of HD in the age groups 45-54.9, 55-64.9 and > or = 65 years respectively, compared to figures of 3.4, 7.5 and 10.4/1000 subject-years in the corresponding age groups in the general French population. CONCLUSION: Incidence of atherosclerotic CV accidents is nearly three times higher in uraemic patients than in the general population in the same age range in both genders. The fact that incidence and age at onset of first MI was similar in predialysis and in dialysed patients suggests that the uraemic state per se is a main determinant of such accelerated atherosclerosis.

[Single balloon versus Inoue balloon in percutaneous mitral balloon valvuloplasty. Short-term results and complications]. / Balãco Unico versus balão de Inoue na valvoplastia mitral percutânea por balão. Resultados imediatos e complicações.

PURPOSE: To assess short-term results and complications of percutaneous mitral balloon valvuloplasty (PMBV) performed with Inoue balloon (IB) and single low profile balloon (SB). METHODS: We performed 390 PMBV procedures, 29 with IB and 337 with SB. There were no differences in age, sex, echocardiographic score distribution and echocardiographic mitral valve area (MVA). RESULTS: We performed 29 complete procedures with IB and 330 of 337 in SB group. Comparing IB and pre and pos-PMBV data we obtained: mean pulmonary artery pressure (MPAP) 36 +/- 15 and 39 +/- 14 mmHg, p = 0.2033, mean mitral gradient 17 +/- 6 and 20 +/- 77 mmHg, p = 0.0396 and MVA 0.9 +/- 0.2 and 0.9 +/- 0.2 cm2, p = 0.8043 and pos-PMBV:MPAP 25 +/- 8 and 28 +/- 10 mmHg, p = 0.2881, gradient 5 +/- 3 and 5 +/- 4 mmHg, p = 0.2778 and MVA 2.2 +/- 0.2 and 2.0 +/- 0.4 cm2, p = 0.0362. Mitral valve (MV) was competent in 26 patients in IB and in 280 in SB group and we had +/4 mitral regurgitation in 3 patients in IB and in 57 in SB group (p = 0.3591) pre-PMBV respectively and pos-PMBV there was also no difference in MV competence (p = 0.7439). CONCLUSION: Both techniques were effective. Hemodynamic data were also similar although MVA was greater in IB group after PMBV.

Baläo único versus baläo de inoue na valvoplastia mitral percutânea por baläo: resultados imediatos e complicaçöes / Single balloon versus inoue balloon in percutaneous mitral balloon valvuloplasty: short-term results and complications

Objetivo - Avaliar os resultados imediatos e complicaçöes da valvoplastia mitral percutânea por baläo (VMPB), com o baläo de Inoue (BI) e com o baläo único (BU). Métodos - Dentre 390 procedimentos utilizaram-se o BI em 29 procedimentos e o BU de baixo perfil em 337. Näo houve diferença na idade e sexo nos 2 grupos. O grupo BI era menossintomático (p=0,0015). Não houve diferença na distribuição do escore ecocardiográfico e da área valvar mitral (AVM) pré-VMPB. Resultados - Quando compararam-se os 2 grupos entre si, os resultados nos grupos BI e BU foram, respectivamente: pré-VMPB para pressäo pulmonar média (PPM) ..."fórmula"...Só houve complicaçöes no grupo BU. Conclusäo - As duas técnicas foram eficientes. Os resultados hemodinâmicos foram semelhantes, embora a AVM pós-VMPB do grupo do BI foi maior.

Hyperhomocysteinemia is associated with atherosclerotic occlusive arterial accidents in predialysis chronic renal failure patients.

Hyperhomocysteinemia has been shown to constitute an independent risk factor for premature occlusive arterial disease. Moderate hyperhomocysteinemia is present in chronic uremic patients, who often develop premature atherosclerosis, but no direct evidence of an association between the occurrence of atherosclerotic cardiovascular accidents (CVAs) and hyperhomocysteinemia has yet been reported in such patients. We serially determined total plasma homocysteine (Hcy) levels in a cohort of 93 consecutive chronic renal failure, undialyzed patients (57 males, 36 females) with creatinine clearance (Ccr) < 50 ml/min.1.73 m2 and age > or = 50 years at start of follow-up, together with serial assessment of Ccr and blood lipid parameters. From January 1989 to December 1995, 24 patients (group 1) experienced myocardial infarction (18 cases, 13 males) or cerebral infarction (6 cases, 3 males) while the remaining 69 (group 2) remained free of CVAs. Patients in groups 1 and 2 did not differ with respect to age (66 +/- 1.8 vs. 65 +/- 1.1 years, mean +/- Se) or serum creatinine (227 +/- 24 vs. 251 +/- 36 mumol/l) at onset of a CVA (group 1) or at the end of follow-up (group 2). The mean Hcy level was significantly higher in group 1 (20.7 +/- 1.6 vs. 12.8 +/- 0.5 mumol/l, p < 0.0001), as was the proportion of patients with Hcy in excess of 14 mumol/l, the upper limit in healthy controls (83 vs. 30%, p < 0.0001). Logistic regression analysis identified Hcy as an independent risk factor for CVA, with an odds ratio of 11.4 (95% confidence interval 3.5-37.7), which remained significant after adjustment on other variables. We conclude that an elevated Hcy level is associated with a risk of occlusive arterial accidents in patients with chronic renal failure and that hyperhomocysteinemia contributes to the accelerated atherosclerosis complicating chronic uremia.

Incidence and risk factors of atherosclerotic cardiovascular accidents in predialysis chronic renal failure patients: a prospective study.

BACKGROUND: Accelerated atherosclerosis resulting in an abnormally high incidence of coronary and cerebrovascular occlusive accidents has been repeatedly reported in dialysis patients, but incidence and risk factors of such complications in chronic renal failure (CRF) predialysis patients are debated. METHODS: We prospectively assessed the incidence of first myocardial and cerebral infarction episodes in a cohort of 147 CRF patients (99 male) followed from January 1985 to December 1994. Relevant clinical and laboratory risk factors for atherogenesis were determined at yearly intervals. They included blood pressure, smoking, blood lipids, fibrinogen, and homocysteine which were compared in patients with (CVA+) or without (CVA-) occurrence of cardiovascular (CV) atherosclerotic accidents. RESULTS: Incidence of CV accidents was nearly three times higher in CRF patients than in the French general population in both genders. In particular, incidence of myocardial infarction in male patients aged 45-55, 55-65 and > 65 years was 7.6, 18.2, and 27.8/1000 patient-years, respectively, compared to 3.4, 8.9, and 10.4/1000 subject-years in the general population. Although age and degree of renal failure at onset of CV events or at end of follow-up did not differ between CVA+ and CVA- groups, cigarette smoking (24.5 [SD 24.3] vs 8.2 [14.7] pack-years, P < 0.0001) and systolic blood pressure (159 [19] vs 148 [19] mmHg, P < 0.001) were markedly higher in CVA+ patients. Similarly, mean plasma HDL-cholesterol was lower, whereas LDL-cholesterol, triglycerides, apoB, Lp(a), fibrinogen, and homocysteine levels all were significantly higher in CVA+ than in CVA- patients. Multivariate Cox analysis identified cigarette smoking, systolic pressure, HDL cholesterol, and fibrinogen as independent risk factors for developing CV accidents. CONCLUSIONS: Incidence of atherosclerotic CV complications is abnormally high in predialysis CRF patients, suggesting that the uraemic state per se is associated with atherogenesis. As several of the identified clinical and metabolic risk factors for such accidents are potentially remediable by specific therapeutic interventions, prophylactic measures should be initiated long before start of renal replacement therapy.

Pregnancy in women with reflux nephropathy.

Reflux nephropathy is one of the most prevalent renal diseases and a leading cause of chronic renal failure in women-of childbearing age. To evaluate the issue and possible complications of pregnancy in women with reflux nephropathy, we retrospectively analyzed fetal and maternal outcome in 158 women who had 375 pregnancies between 1965 and 1994. The overall fetal death rate was 10.2% and tended to decrease in the 1985 to 1994 decade as compared to the preceding period (8.4% vs. 12.6%). The relative risk of fetal death was 4.8 times greater hypertension was present at conception than in normotensive patients. Fetal death rate was also higher in patients with impaired renal function that in those with serum creatinine < 0.11 mmol/liter at conception (36.7% vs. 7.7%, P < 0.0001). Urinary tract infection accounted for frequent morbidity but seldom resulted in fetal mortality. Maternal renal disease was unaffected by pregnancy, excepted for 4 of the 21 patients with pre-existing renal failure who exhibited an irreversibly accelerated course after pregnancy. We conclude that pregnancy is essentially successful and uneventful in patients diagnosed with reflux nephropathy who have normal blood pressure and preserved renal function, whereas the fetal prognosis is more compromised and there is a risk of accelerated progression of maternal renal disease when serum creatinine concentration is in excess of 0.22 mmol/ liter. This suggests that women with reflux nephropathy should preferably conceive before having reached that stage of renal failure.

Age and gender-related incidence of chronic renal failure in a French urban area: a prospective epidemiologic study.

OBJECTIVE: To determine the age- and gender-related incidence of chronic renal failure in a French urban area. METHODS: Prospective study of adult patients newly identified as having established, chronic renal failure defined by serum creatinine (Scr) > or = 200 mumol/l, with the cooperation of all nephrology and dialysis units in the Ile de France district (10,660,000 inhabitants) during a 1-year period. RESULTS: 2775 patients (1780 males, 995 females) were referred with Scr > or = 200 mumol/l between July 1991 and June 1992, an overall incidence of 260/million population. 847 had advanced renal failure (Scr > or = 500 mumol/l) and 541 patients (19.5%) were > or = 75 years of age. The age-related incidence was 92, 264, 523 and 619/million population in the age groups 20-39, 40-59, 60-74 and > or = 75 years old, respectively. The annual incidence was twice as high in males than in females up to 75 years and three times as high in patients > or = 75 years (1124 vs 356/million population). Based on the proportion of patients reaching end-stage renal failure within one year of referral, the minimal estimation of the need for supportive therapy is 81/million/year. CONCLUSIONS: This epidemiological study in a large French urban area indicates an incidence of 260 patients per million population annually referred to nephrology units for chronic renal failure defined by Scr > or = 200 mumol/l, with a marked preponderance of males and a dramatic increase of incidence with age in both genders.

Influence of pregnancy on the course of primary chronic glomerulonephritis.

According to some nephrologists, pregnancy has damaging effects on renal function in primary glomerulonephritis, but the evidence is conflicting. We evaluated the effect of pregnancy on the occurrence of end-stage renal failure (ESRF) in 360 patients with various histological forms of primary glomerulonephritis but with normal renal function (serum creatinine < or = 0.11 mmol/L) at presentation. In actuarial analyses, overall ESRF-free survival did not significantly differ between women who became pregnant after clinical onset of renal disease (n = 171) and those who did not conceive (n = 189). Furthermore, in a case-control study pregnancy did not emerge as a risk factor for progression to ESRF (odds ratio 1.15 [95% CI 0.61-2.18]), whereas the type of glomerulonephritis and hypertension were major determinants. We conclude that pregnancy does not affect the course of renal disease in patients who have normal renal function at conception.