Fusion of the planes of the liver: an anatomic entity merging the midplane and the left intersectional plane

BACKGROUND: Alignment of the gallbladder fossa and the round ligament may be associated with an almost unknown portal vein branching anomaly. STUDY DESIGN: Ultrasonographic imaging allowed detection of this anomaly, which we characterized as fusion of the planes of the liver. When appropriate, additional specific radiologic examinations were performed (CT scanner supplemented with a three-dimensional reconstruction, a biliary cartography, or an angiography). Surgical consequences were studied from this series and from the literature. RESULTS: Seven patients (0.5%) had the following criteria: 1) round ligament, gallbladder fossa, and termination of the portal vein occurring in the same plane; 2) typical portal vein branching, including a right posterior branch, left branches, and a main medial branch terminated by the Rex's recessus; 3) two main hepatic veins without a significant middle hepatic vein; and 4) absence of the horizontal part of the left hepatic duct. Fusion of the planes may have been involved in two cases of iatrogenic bile duct injury and contraindicated a tumor resection and a right-liver donation. A review of the literature revealed that lack of recognition of the fusion of the planes led to a high proportion of surgical iatrogenic injury. Fusion of the planes could result from incomplete development of the central part of the liver, in agreement with embryologic knowledge. CONCLUSIONS: Knowledge of the fusion of the planes by hepato-biliary surgeons is important. This anomaly may lead to serious complications if it remains undetected during liver resection or bile duct surgery.     

Renal Cell Carcinoma Associated with Tumor Thrombus in the Inferior Vena Cava: Surgical Strategies

The purpose of this study was to evaluate strategies used for surgical management of renal cell carcinoma with a tumoral thrombus extension in the inferior vena cava (IVC). From January 2000 to December 2001, urological and vascular surgeons jointly undertook surgical treatment on 10 patients with renal cell carcinoma and tumor thrombus in the IVC. There were five women and five men, with a mean age of 60.2 years. The limit of thrombus extension, classified according to the Neves and Zincke system, was level I (renal) in one patient, level II (infrahepatic) in one, level III (retrohepatic) in three, and level IV (atrial) in five. Exposure was achieved by chevron bilateral subcostal laparotomy associated with sternotomy in three patients, bilateral subcostal laparotomy in six, and median sternolaparotomy in one. Radical nephrectomy associated with caval thrombectomy was performed in all patients. Cardiopulmonary bypass was used in four of the five level IV patients. The fifth patient was contraindicated for cardiopulmonary bypass. Transesophageal echography (TEE)-guided endoluminal occlusion of the unobstructed infradiaphragmatic IVC was performed in patients with level III thrombus. Clamping of the IVC was performed in patients with levels I and II thrombus. All procedures were assisted by continuous TEE surveillance. No intraoperative gas or tumor emboli were detected by TEE. The mean number of red blood cell units transfused during the course of hospitalization was 9.7 (range 2-22, median 9). One patient died of multiple organ failure on the day 28 after the procedure. The mean duration of hospitalization was 16 days. The mean duration of follow-up was 9.7 months. During follow-up, two of the remaining nine patients died due to tumor recurrence. Tumor recurrence was also detected in one of the seven surviving patients. Surgery for renal cell carcinoma with tumor thrombus in the IVC must be carried out in a specialized facility with the assistance of TEE surveillance and, in some cases, cardiopulmonary bypass. Operative treatment improves the prognosis of renal cell carcinoma with tumor thrombus in the IVC. In patients with level III thrombus, TEE-guided endoluminal occlusion of the unobstructed infradiaphragmatic IVC simplifies surgical management by obviating the need for exposure of the retrohepatic and supradiaphragmatic IVC.Presented at the Seventeenth Annual Meeting of the Société de Chirurgie Vasculaire de Langue Française, May 29-31, 2002, Liege, Belgium.     

Human tonsil implants xenotransplanted in SCID mice display broad lymphocytic diversity and cellular activation profile similar to those in the original lymphoid organ

BACKGROUND: Models consisting of human immune cells in suspension transferred to severe combined immune deficient (SCID) mice have been invaluable for studying immune response, autoimmunity, and lymphomagenesis. The dissemination of human cells within the mouse body hampers immune functionality with time and favorites the development of human graft vs. mouse host (GvH) disease. To circumvent these limitations we surgically implanted tonsil pieces subcutaneously in SCID animals (hu-ton-SCID mice). Recall humoral responses was elicited and animals did not suffer from signs of GvH disease. A detailed cell subset and cell activation analysis of implants has not yet been reported. METHODS: Implants from 86 hu-ton-SCID mice were evaluated by immunohistochemistry and flow cytometry analyses to assess human lymphoid cell subpopulation surviving with time after implantation, and to evaluate status of human cell activation. Results: B cells persist over 3 months in implants. The proportion of class and type-specific Ig+ cells varied between implants, but as a whole IgG+ cells were more abundant than IgA+, and IgM+ cells, and kappa+ cells predominated over lambda+ cells. The mean proportions of these cells resemble those in the original tonsil. Fine analysis of CD19+ B cells demonstrated no expansion of activated (CD5+, CD23+, CD69+) B cells in implants compared with tonsils, and a decrease of CD19+CD77+ B cells corresponding to a centroblastic phenotype, which is consistent with the disappearance of follicular structure in implants. Double positive CD20+CD27+ memory B cells were detected in implants by immunohistochemistry. T cell CD4+CD8-/CD4-CD8+ ratios were about 4 in implants, that is similar to those in tonsils, and there was no expansion of CD3+CD4+CD8+ and of CD3+CD4-CD8- T-cell subpopulations. T cells activation markers (CD25, CD69) were similarly expressed in implants and tonsils, and implants contained cells with a memory T cell phenotype (CD45RO). Finally cells within implants depicted a low rate of proliferation when assessed by Ki-67 expression levels. Conclusions: Compared with original tonsils, tonsil implants in hu-ton-SCID mice lose the germinal center architecture, which is correlated with the decrease of CD77+ B cells, but conserve T and B cell subpopulation diversity, notably memory cells. In addition, implant T and B cells are not differently activated when compared with those in original tonsils and do not proliferate extensively. These observations indicate indirectly absence of GvH reaction at the cellular level in this model. Collectively, the detailed implant cellular characterization in the hu-ton-SCID model provides a strong rationale for the use of this model in the study of human recall antibody response.     

Immediate postoperative refeeding in orthopedic surgery is safe

The purpose of this retrospective study was to investigate the morbidity of immediate postoperative refeeding after orthopedic surgery. We included all the 1077 patients who underwent orthopedic surgery between January and December 2003 at our military teaching hospital. General anesthesia was performed in 37% of the patients (n = 398), 24% (n = 259) had combined general and regional anesthesia, and 39% (n = 420) had isolated regional anesthesia (spinal anesthesia and/or peripheral regional anesthesia). After surgery, each patient was allowed free access to solid and liquid food immediately after discharge from the postanesthetic care unit. Although no systematic nausea and vomiting prophylaxis was performed, only 7% (n = 75) of the patients had postoperative nausea and vomiting during the first 48 h. Moreover, neither deglutition trouble nor aspiration syndrome was observed during that period. Our results suggest that immediate postoperative refeeding after orthopedic surgery is safe, does not increase postoperative nausea and vomiting, and probably increases the comfort of patients.     

The outcome of prenatally diagnosed renal tumors

PURPOSE: We assessed the incidence of perinatal morbidity and evaluated the outcome in children with prenatally diagnosed renal tumors in a retrospective multicenter study. MATERIALS AND METHODS: A review of the records of patients from 20 institutions identified 28 children with prenatally diagnosed renal tumors. Prenatal findings, clinical charts, and radiological, surgical and pathological reports were reviewed in this study. RESULTS: There were 26 congenital mesoblastic nephromas and 2 Wilms tumors. One or more complications were identified in 20 of the 28 cases (71%) during the perinatal period. Polyhydramnios was observed in 11 fetuses (39%), 2 presented with hydrops fetalis and 7 presented in acute fetal distress requiring emergency cesarean section, of which 1 died in utero before delivery. Median gestational age of the 27 neonates born alive was 35 weeks (range 29 to 39), including 13 (46%) who were pre-term (less than 34 weeks of gestation). Complications at birth included hemodynamic instability in 3 newborns, of whom 2 underwent emergency surgery, respiratory distress syndrome in 8 (30%) and hypertension in 6 (22%). Surgical complications occurred in 7 patients (26%), including tumor rupture in 1 and intraoperative bleeding with postoperative death in 1. At a median followup of 42 months (range 2 to 105) 26 of the 27 children were in complete remission. CONCLUSIONS: Fetal renal tumors have an excellent oncological outcome but a high risk of perinatal complications. Prenatal diagnosis should allow planning the delivery at a pediatric tertiary care center to avoid a potentially life threatening condition in neonates in the first hours of life.     

Cystic renal cell carcinomas in adults. Is preoperative recognition of multilocular cystic renal cell carcinoma possible?

PURPOSES: We correlated clinicopathological and imaging features of multilocular cystic renal cell carcinoma (MCRCC) to propose preoperative criteria for therapeutic modalities. MATERIALS AND METHODS: A total of 24 RCCs with a chiefly cystic component were identified from 1993 to 2002. In each case histological slides and available imaging studies were retrieved. Two tumor groups were defined, namely MCRCC and clear RCC with cystic change (CRCC) by intrinsic growth or necrotic degeneration. Radiological correlation using computerized tomography and magnetic resonance imaging was performed considering criteria such as an expansile nodule, cyst wall thickness and septa. RESULTS: On imaging MCRCC presented as a multilocular cystic mass lacking an expansile nodule, and with regular thin cyst wall and septa. On pathological study MCRCC presented as complex, multilocular cystic carcinoma with septa covered by low nuclear grade clear renal tumor cells without a grossly expansile nodule. They were staged pT1 with a free clinical course. In contrast, CRCC was identified on imaging with an expansile nodule (5 mm or greater), thick, irregular cyst wall and septa. On pathological study CRCC was characterized by a grossly expansile nodule in the septa and/or cyst wall. Nuclear grade and TNM stage were higher in CRCC. CONCLUSIONS: Preoperative recognition of MCRCC is possible using strict computerized tomography and/or magnetic resonance imaging criteria. The current study confirms the low malignant potential of MCRCC. Nephron sparing surgery should be proposed when MCRCC is suspected.     

Quantification methods were developed for selection bias by predictability of allocations with unequal block randomization

BACKGROUND AND OBJECTIVE: A selection of patients for a controlled clinical trial may be biased because of prior knowledge of the treatment. With randomized blocks of known or guessed lengths, some allocations can be predicted with certainty. Previously described methods determine the proportion of predictable cases for blocks of equal lengths. It may be useful to make a calculation for unequal blocks as well to find a method that reduces this predictability. STUDY DESIGN AND SETTING: Quantification methods are developed for series of two and three unequal blocks, using the probability of identifying a long block when it comes before a short one if it starts with a sequence incompatible with the content of a short block. Results are compared with the recently described maximal allocation procedure. RESULTS: Predictability is not always reduced by unequal blocks and is even worse in some cases, compared to equal blocks. Predictability is not necessarily decreased with the maximal allocation procedure. CONCLUSIONS: Before choosing an allocation method, it is important to quantify the predictability of possible options to reduce selection bias. Several practical recommendations are formulated for choosing methods, taking this risk of bias into account.     

Hui and Walter's latent-class reference-free approach may be more useful in assessing agreement than diagnostic performance

BACKGROUND AND OBJECTIVE: Hui and Walter developed a latent class approach to assess the accuracy of a diagnostic procedure when no reference test is available. Our objective was to compare sensitivity and specificity estimates obtained with this reference-free approach and standard approaches, and to examine how and why they differed on a computerized tomography (CT) scan case study. STUDY DESIGN AND SETTING: We compared two sets of sensitivity and specificity estimates from four radiologists independently assessing tumoral and lymph node extension of 85 lung cancer patients with preoperative thoracic CT scan, those obtained relative to pathology findings from surgical specimens (reference set), and those derived from Hui and Walter's approach. RESULTS: The two sets of estimates significantly and markedly differed from each other. From simulations, we found that small-sample bias in Hui and Walter's estimates could be a major factor in explaining this difference. Furthermore, errors in pathology findings could account for part of this difference. Finally, our analyses revealed that the latent classes may differ intrinsically from the reference classes as defined from pathology findings and may have a different interpretation. CONCLUSION: Diagnostic parameters estimated with respect to latent classes may be more useful in providing a complete assessment of interobserver agreement than in assessing diagnostic performance.     

Trypanosomiasis relapse after melarsoprol therapy, Democratic Republic of Congo, 1982-2001

Recently, a high proportion of patients with late-stage Trypanosoma brucei gambiense trypanosomiasis, who had been treated with melarsoprol in some disease-endemic areas, subsequently relapsed. To determine whether the frequency of postmelarsoprol relapses increased over time, we reviewed data from 2,221 trypanosomiasis patients treated with melarsoprol during this period in Nioki, Democratic Republic of Congo, from 1982 to 2001. The frequency of relapses was 5.6%(31/553), 6.8%(35/512), 4.5%(18/398), 11.4%(34/299), and 5.0%(17/343) for those treated from 1982 to 1985, 1986 to 1989, 1990 to 1993, 1994 to 1997, and 1998 to 2001, respectively. The higher frequency of relapses in 1994 to 1997 was associated with an incremental dosage regimen of melarsoprol. In multivariate analysis, after adjustment for treatment regimen, sex, residence, and trypanosomes in cerebrospinal fluid, postmelarsoprol relapses did not increase in Nioki, perhaps because 1) little drug pressure exists; 2) subtherapeutic doses have rarely been administered; 3) little potential exists for the preferential transmission of melarsoprol-resistant strains.