Daily medical education for confined students during coronavirus disease 2019 pandemic: A simple videoconference solution.

The outbreak of coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 infection has recently spread globally and is now a pandemic. As a result, university hospitals have had to take unprecedented measures of containment, including asking nonessential staff to stay at home. Medical students practicing in the surgical departments find themselves idle, as nonurgent surgical activity has been canceled, until further notice. Likewise, universities are closed and medical training for students is likely to suffer if teachers do not implement urgent measures to provide continuing education. Thus, we sought to set up a daily medical education procedure for surgical students confined to their homes. We report a simple and free teaching method intended to compensate for the disappearance of daily lessons performed in the surgery department using the Google Hangouts application. This video conference method can be applied to clinical as well as anatomy lessons.

Laparoscopic resection for T4 colon cancer: perioperative and long-term outcomes.

Laparoscopic resection has been considered a contraindication for T4 colorectal cancer. It is argued that it is a challenging and demanding procedure with high conversion rate, inadequate oncologic clearance and surgical outcomes. There are only a few data on short- and long-term operative results. This review aimed at assessing feasibility and operative and oncologic results of laparoscopic resection for T4 colorectal cancer.

Laparoscopic Colorectal Cancer Resection in High-Volume Surgical Centers: Long-Term Outcomes from the LAPCOLON Group Trial.

BACKGROUND: Strong evidence has confirmed the benefit of laparoscopy in colorectal cancer resection but remains a challenging procedure. It is not clear that such promising results in selected patients translate into a favorable risk-benefit balance in real practice. We conducted a multicenter national observational registry to assess operative and oncologic long-term outcomes following laparoscopic colorectal cancer resection. METHODS: All patients with laparoscopic colorectal cancer resection between 2001 and 2004 were included. Data were extracted from the prospective Italian national database of 10 high-volume centers (≥40 colorectal cancer laparoscopic resections per year). Surgical technique and follow-up were standardized. Survivals were analyzed by Kaplan-Meier method. RESULTS: We reported 1832 patients with colon (58.5%) and rectal cancer (41.5%). TNM stage was 0-I-II in 1044 patients (57%) and III-IV in 788 patients (43%). Surgery included a totally laparoscopic procedure in 1820 patients (99.3%). Conversion was 10.5%. Postoperative morbidity and 30-day mortality rates were 17 and 1.2%, respectively. Clinical anastomotic leakage rate was 8.3% (n=152). R0 resection was 95%. With a median follow-up of 54.2 months, cancer recurrence rate was 13.3%. At 5 years, cancer-free survival was 86.7%. Upon multivariate analysis, age (P=0.001) and TNM stage (P<0.001) were associated with cancer-free survival. Predictive factors of cancer recurrence were gender (P=0.029) and TNM stage (P<0.001). CONCLUSIONS: In high-volume centers and non-selective patients, laparoscopic colorectal resection for cancer achieves good operative results with satisfactory long-term oncologic results. Even in the laparoscopy era, age, gender, and TNM stage remain the most powerful predictor of oncologic outcomes.

Does pathologic response of rectal cancer influence postoperative morbidity after neoadjuvant radiochemotherapy and total mesorectal excision?

BACKGROUND: A pathologic complete response (pCR) can be observed in up to 25% of patients after preoperative chemoradiotherapy for rectal cancer and is associated with an improved long-term prognosis. However, few data are available regarding the effect of pCR on postoperative morbidity. This study aimed to assess the impact of the pCR on postoperative outcomes after laparoscopic total mesorectal excision (TME). METHODS: A prospectively maintained database (2006-2011) was reviewed for all consecutive patients (n = 143) undergoing laparoscopic TME for mid or low rectal cancer after neoadjuvant chemoradiotherapy. Postoperative data were compared for pCR-group and non-pCR-group. A pCR was defined as the absence of gross and microscopic tumor in the specimen, irrespective of the nodal status (ypT0). RESULTS: Thirty-three patients (23%) had a pCR. Median operating time was greatly shorter in the pCR-group (230 minutes, 180-360), compared with the non-pCR-group (240 minutes, 130-420, P = .02). Lymph node involvement was noted for 12% of the patients in the pCR-group and 33% of the patients in the non-pCR-group (P = .91). Clavien Dindo grade 3 and 4 complications (6% vs 22%, P = .04), infection related morbidity (47% vs 76%, P = .04), and clinical anastomotic leakage rates (9% vs 29%, P = .02) were lesser in the pCR group compared with the non-pCR group. Mean duration of hospital stay was lesser in the pCR-group (9 vs 12 days, P = .01). CONCLUSION: This study showed that Clavien Dindo grade 3 and 4 complications, including anastomosis leakage, and infection related complications rates were lesser in patients with pathologic complete response after RCT and laparoscopic TME for rectal cancer.

Type 2 diabetes mellitus as a risk factor for intestinal resection in patients with superior mesenteric vein thrombosis.

BACKGROUND & AIMS: The most serious complication of acute mesenteric vein thrombosis (MVT) is acute intestinal ischaemia requiring intestinal resection or causing death. Risk factors for this complication are unknown. To identify risk factors for severe intestinal ischaemia leading to intestinal resection in patients with acute MVT. METHODS: We retrospectively analysed consecutive patients seen between 2002 and 2012 with acute MVT in 2 specialized units. Patients with cirrhosis were excluded. We compared patients who required intestinal resection to patients who did not. RESULTS: Among 57 patients, a local risk factor was identified in 14 (24%) patients, oral contraceptive use in 16 (29%), and at least one or more other systemic prothrombotic condition in 25 (44%). Five (9%) patients had diabetes mellitus (DM), 33 (58%) had overweight or obesity, 9 (18%) had hypertriglyceridemia and 10 (19%) had arterial hypertension. Eleven patients (19%) underwent intestinal resection. DM was significantly associated with intestinal resection (P = 0.02) while local factors or prothrombotic conditions were not. Computed tomography (CT) scans performed at diagnosis found that occlusion of second order radicles of the superior mesenteric vein was more frequently observed in patients who underwent intestinal resection (P = 0.009). CONCLUSIONS: In acute MVT, patients with underlying DM have an increased risk of requiring intestinal resection. Neither local factors nor systemic prothrombotic conditions are associated with intestinal resection. When CT scan shows the preservation of second order radicles of the superior mesenteric vein, the risk of severe resection is low.

Erasable and reversible wrinkling of halogenated rubber surfaces.

Few surfaces can exist at rest in either wrinkled or unwrinkled states and switch reversibly between these states. Here, we report a new approach to creating reversibly wrinkling systems using the halogenation of rubber to induce a local increase in the glass-transition temperature within a thin layer at the surface. Such systems are obtained by the bromination of molded rubber films. By means of thermomechanical experiments and in situ observations, we show that microscopic wrinkles are produced by unstretching a stretched film below the glass-transition temperature of the brominated layer. These surface patterns are erased within seconds when the wrinkled layer is heated to above its glass transition and recovers its initial equilibrium dimensions. New wrinkles can be produced and erased repeatedly on the same surface. A model is proposed that takes into account the existence of a gradient in bromine content along the thickness of the modified layer. It describes the viscoelastic behavior of these brominated films and captures the temperature dependencies of the thickness of the glassy layer and of the wrinkle wavelength.

Increased intestinal absorption by segmental reversal of the small bowel in adult patients with short-bowel syndrome: a case-control study.

BACKGROUND: Segmental reversal of the small bowel (SRSB) is proposed in patients with short-bowel syndrome (SBS) as a rehabilitative therapy, but its effects on absorption have not been studied. OBJECTIVE: We aimed to determine intestinal macronutrient absorption and home parenteral nutrition (HPN) dependence in SBS patients with intestinal failure. DESIGN: We included in a retrospective study all consecutive patients who had an SRSB between 1985 and 2010 and underwent a study of macronutrient absorption. Patients were matched to SBS controls with the same digestive characteristics. Energy and macronutrient absorption were measured. The dependence on HPN was expressed by the number of infusions per week and by the calories infused daily divided by the basal energy expenditure multiplied by 1.5. RESULTS: Seventeen patients who had an SRSB were matched to 17 control patients. Intestinal absorption was higher in the SRSB group for total calories (69.5% compared with 58.0%), fat (48.4% compared with 33.2%), and protein (62.7% compared with 53.4%) (P < 0.05). Median oral autonomy was 100% ± 38.4% in the SRSB group, whereas it was 79% ± 39.6% in the control group (P < 0.05). The number of calories infused was lower in the SRSB group (500 ± 283 compared with 684 ± 541; P < 0.05), as was HPN dependence (33% ± 20% compared with 48% ± 38%; P < 0.05) at the time of the study. CONCLUSION: SRSB allows a gain in macronutrient absorption, which is associated with a lower HPN dependence. To our view, SRSB should be integrated in intestinal rehabilitative adult programs.

Long-term outcome after extensive intestinal resection for chronic radiation enteritis.

INTRODUCTION: Management of chronic radiation enteritis is often controversial, particularly due to the risk of short bowel syndrome. METHODS: One hundred and seven chronic radiation enteritis patients with short bowel syndrome were studied retrospectively between 1980 and 2009. Survival and home parenteral nutrition dependence rates were evaluated with univariate and multivariate analysis. RESULTS: The survival probabilities were 93%, 67% and 44.5% at 1, 5 and 10 years, respectively. On multivariate analysis, survival was significantly decreased with residual neoplastic disease (HR=0.21 [0.11-0.38], p<0.001), an American Society of Anesthesiologists score >3 (HR=0.38 [0.20-0.73], p=0.004) and an age of chronic radiation enteritis diagnosis >60 years (HR=0.45 [0.22-0.89], p=0.02). The actuarial home parenteral nutrition dependence probabilities were 66%, 55% and 43% at 1, 2 and 3 years, respectively. On multivariate analysis, this dependence was significantly decreased when there was a residual small bowel length >100 cm (HR=0.35 [0.18-0.68], p=0.002), adaptive hyperphagia (HR=0.39 [0.17-0.87], p=0.02) and the absence of a definitive stoma (HR=0.48 [0.27-0.84], p=0.01). CONCLUSION: The survival of patients with diffuse chronic radiation enteritis after extensive intestinal resection was good and was mainly influenced by underlying comorbidities. Almost two-thirds of patients were able to be weaned off home parenteral nutrition.

Effects of a multimodal management strategy for acute mesenteric ischemia on survival and intestinal failure.

BACKGROUND & AIMS: Acute mesenteric ischemia (AMI) is an emergency with a high mortality rate; survivors have high rates of intestinal failure. We performed a prospective study to assess a multidisciplinary and multimodal management approach, focused on intestinal viability. METHODS: In an Intestinal Stroke Center, we developed a multimodal management strategy involving gastroenterologists, vascular and abdominal surgeons, radiologists, and intensive care specialists; it was tested in a pilot study on 18 consecutive patients with occlusive AMI, admitted to a tertiary center from July 2009 to November 2011. Patients with left ischemic colitis, nonocclusive AMI, chronic mesenteric ischemia, and other emergencies were excluded. Patients received specific medical management: revascularization of viable small bowel and/or resection of nonviable small bowel; 12 patients received arterial revascularization. We evaluated the percentages of patients who survived for 30 days or 2 years, the number with permanent intestinal failure, and morbidity. Lengths and rates of intestinal resection were compared with or without revascularization, and in patients with early or late-stage disease. RESULTS: Patients were followed up for a mean of 497 days (range, 7-2085 d); 95% survived for 30 days, 89% survived for 2 years, and 28% had morbidities within 30 days. Intestinal resection was necessary for 7 cases (39%), with mean lengths of intestinal resection of 30 cm and 207 cm, with or without revascularization, respectively (P = .03). Among patients with early or late-stage AMI, rates of resection were 18% and 71%, respectively (P = .049). Patients with early stage disease had shorter lengths of intestinal resection than those with late-stage disease (7 vs 94 cm; P = .02), and spent less time in intensive care (2.5 vs 49.8; P = .02). CONCLUSIONS: A multidisciplinary and multimodal management approach might increase survival of patients with AMI and prevent intestinal failure.

Bilobar colorectal liver metastases: a new model for preclinical studies.

SUMMARY: This study aimed to develop a new model of colorectal liver metastases (LM) in the rat. Both single macroscopic and multiple bilobar microscopic LM were investigated, as this closely resembled the human situation, before right hepatectomy was performed for 'single' right LM. The single macroscopic LM was elicited by direct injection of DHD/K12 colorectal cancer cells under the capsule of the median liver lobe in immunocompetent BDIX rats. The bilobar micrometastases were elicited by intraportal injection of DHD/K12 cells. A preliminary protocol was conducted to assess the dose of cells required to inject in to the portal vein, using 10(6) , 2 × 10(6) and 3 × 10(6) DHD/K12 cells (n = 15 rats). The resultant protocol for the experimental model used intraportal injection of 10(6) DHD/K12 cells and direct injections of 0.5 × 10(6) , 10(6) and 1.5 × 10(6) DHD/K12 cells (n = 15 rats). For both protocols, BDIX rats were sacrificed at day 30 after injection. The preliminary protocol showed that intraportal injection of 10(6) DHD/K12 cells was associated with bilobar micrometastases of 0.8 mm mean diameter at day 30. The main protocol assessed that direct injection of 0.5 × 10(6) under the liver median lobe capsule and intraportal injection of 10(6) DHD/K12 cells were associated at day 30 with a single macroscopic metastasis confined to a liver lobe and bilobar micrometastases, without peritoneal carcinomatosis or lung metastasis. Thus we have developed a new experimental model of bilobar colorectal LM including both macro- and microscopic colorectal LMs, which mimics the human situation and which will be useful in preclinical studies.

Segmental reversal of the small bowel can end permanent parenteral nutrition dependency: an experience of 38 adults with short bowel syndrome.

OBJECTIVE: This study aimed to assess the results of segmental reversal of the small bowel (SRSB) in patients with short bowel syndrome (SBS) who were "permanently" dependent on parenteral nutrition (PN) and to identify possible prognostic factors for weaning. SUMMARY BACKGROUND DATA: SRSB is a nontransplant surgical option for patients with SBS who require long-term PN. Few studies have reported outcomes in humans. METHODS: : All patients who were permanently dependent on PN and underwent a SRSB between 1985 and 2010 for SBS were included. The data were retrospectively retrieved. RESULTS: Thirty-eight patients underwent SRSB. The median age was 55.5 years (range, 18-76). The median length of the small bowel remnant was 49 cm (20-140), including a reversed segment of 10 cm (6-15). The median follow-up was 57.7 months (1-304). At the 5-year follow-up, 17 patients had been weaned from PN (45%). In the remaining patients, PN dependency had decreased from 7 ± 1 to 4 ± 1 days per week. The survival rate was 84%. The prognostic factors for weaning were a short time between subtotal enterectomy and SRSB (P = 0.036), a longer than typical stay in the nutrition unit (P = 0.035), and an SRSB longer than 10 cm (P = 0.024). CONCLUSIONS: SRSB has a role as a conservative alternative to small bowel transplantation in patients with SBS permanently dependent on PN. With a segmental reversal of 10 to 12 cm, almost half of the patients can be expected to be weaned from PN.

The expression of the hypoxia markers CA9 and CXCR4 is correlated with survival in patients with neuroendocrine tumours of the ileum.

BACKGROUND/AIM: The hypoxia-inducible factor pathway regulates the expression of a diverse group of molecules such as CA9 and CXCR4. Our aim was to investigate the expression of these markers in a series of patients with an ileal neuroendocrine tumour (IET) at various stages of tumorigenesis. METHODS: The immunohistochemical expression of CA9 and CXCR4 was examined in 51 patients with a resected IET. A 'hypoxic score' was calculated, integrating the expression of both CA9 and CXCR4 (hypoxic score 0: absence of expression of both molecules; hypoxic score 1: expression of CXCR4 and/or CA9). Results were compared to histoprognostic factors (including tumour size, stage and grade, WHO and TNM classifications, presence of vascular or perineural invasion, presence of a fibrotic stroma and microvascular density) and to survival. RESULTS: All tumours were well differentiated. 69% of tumours were less than 25 mm. 46% of tumours largely infiltrated the intestinal wall (≥T3, subserosa and serosa) and 90% were classified as N1 and/or 63% as M1. 57% of tumours were of grade G1, 43% of grade G2. Grade G2 (p=0.004) and larger tumour infiltration (≥T4; p=0.03) correlated with lower survival. Hypoxic score 1 correlated with a greater tumour size (p=0.034), larger tumour infiltration (T3 or T4; p=0.001), grade G2 (p=0.046), presence of lymph node metastasis (p=0.0066) and with lower survival of patients (p=0.03). CONCLUSION: The hypoxia-inducible factors CA9 and CXCR4 were found associated to the malignant progression of neuroendocrine tumours of the ileum. Their expression may reflect higher tumour aggressivity.

Safety, feasibility, and short-term outcomes of single port access colorectal surgery: a single institutional case-matched study.

BACKGROUND: Feasibility of single port access (SPA) colorectal surgery has been established for various procedures from ileocecal resection to proctectomy. Nevertheless, its benefits compared to conventional laparoscopy still need to be assess. The aim of this study was to compare SPA to conventional colorectal laparoscopic surgery in a single institutional case-matched study. METHODS: From July 2009 to July 2010, 25 SPA colorectal resections were matched on main predictive risk factors of postoperative complications, in a one to two fashion, with patient having the same procedure for the same indication by conventional laparoscopy. RESULTS: Patient characteristics were comparable between both groups. SPA was successfully performed in 24 of 25 patients, with a need to conversion to standard laparoscopy in one case (4%). SPA was associated with a significantly shorter median operative time (130 vs 180 min, p = 0.04) and hospital stay (6 vs 7 days, p = 0.005). Postoperative morbidity rates were similar between the two groups (4% vs 16%, p = 0.25). CONCLUSION: SPA colorectal resection can be safely performed in selected patients with results comparable to those observed after conventional laparoscopic surgery. However, larger studies including randomized controlled trail are needed to demonstrate possible benefits of SPA colorectal resection over conventional colorectal laparoscopic surgery.

Mortality after colorectal cancer surgery: a French survey of more than 84,000 patients.

OBJECTIVES: This study aimed to identify risk factors of postoperative 30-day mortality (POM) after colorectal cancer resection. SUMMARY: Meta-analyses have failed to demonstrate any significant benefit of laparoscopy in terms of postoperative mortality. This could be explained by the lack of a large sample size. METHODS: All patients who underwent colorectal resection for cancer between 2006 and 2008 in France were included. Data were extracted from the French National Health Service Database. A multivariate analysis evaluating risk factors for POM was performed including the following factors: age, gender, tumor location, associated comorbidities, emergency surgery, synchronous liver metastasis, malnutrition, and surgical approach. RESULTS: During the 3-year period, a total of 84,524 colorectal resections for colorectal cancer were performed: 22,359 through laparoscopy (26%) and 62,165 through laparotomy (74%). From 2006 to 2008, laparoscopic approach rate increased from 23% to 29% (P < 0.001). POM was 5.0%: 2% after laparoscopy and 6% after laparotomy (P < 0.001). In multivariate analysis, 7 independent factors were significantly associated with a higher POM: age 70 years or more [P < 0.001, odds ratio (OR): 3.28; (3.00-3.59)], respiratory comorbidity [P < 0.001, OR: 3.16; (2.91-3.37)], vascular comorbidity [P < 0.001, OR: 2.66; (2.48-2.85)], neurologic comorbidity [P < 0.001, OR: 1.78; (1.51-2.09)], emergency surgery [P < 0.001, OR: 2.68; (2.48-2.90)], synchronous liver metastasis [P < 0.001, OR: 2.63; (2.41-2.86)], and preoperative malnutrition [OR: 1.33; (1.19-1.50)]. Laparoscopic surgery [P < 0.001, OR: 0.59; (0.54-0.65)] was independently associated with a significant decreased POM. CONCLUSIONS: This all-inclusive national study showed that POM after colorectal cancer surgery is significantly reduced in case of age less than 70 years, elective surgery, and absence of synchronous liver metastasis, malnutrition, respiratory, neurologic, or vascular comorbidity. Furthermore, it is suggested that a laparoscopic surgery is independently associated with a decreased POM. This result, observed at a national level, must be considered when choosing the best surgical approach for colorectal cancer treatment.

Predictors of tumor response after preoperative chemoradiotherapy for rectal adenocarcinomas.

The ability to predict response after chemoradiotherapy in rectal adenocarcinoma may allow selecting patients to whom less invasive surgical treatment could be proposed. Tumor hypoxia has been implicated in the mechanisms of resistance to chemoradiotherapy in several malignancies. The aim was to identify morphological criteria and molecular markers of hypoxia associated with chemoradiotherapy response. Clinicopathologic data from 61 patients (35 male, 60.5 ± 10 years) undergoing rectal cancer resection after neoadjuvant chemoradiotherapy were collected. Pretreatment biopsies, available for 40 patients, were immunostained for hypoxia markers (carbonic anhydrase 9, glucose transporter 1, chemokine receptor 4) and microvascular density determination. Mean tumor size was 2.7 ± 1.6 cm. Twenty-one patients (34%) were considered as responders, that is, having significant or complete primary tumor regression without lymph node metastasis. Compared to other patients, responders had significantly more often flat tumors with or without ulceration (57% versus 18%, P = .01) and less vascular and/or neural invasions (9% versus 65%, P < .0001) or tumor necrosis (9% versus 41%, P < .01), respectively. Regarding pretreatment biopsies, carbonic anhydrase 9 expression was significantly lower in responders (7% versus 46%, P = .012). This study showed that tumor necrosis as an overexpression of carbonic anhydrase 9 was an effective molecular marker of postchemoradiotherapy response. This might suggest a key role of hypoxia in resistance mechanisms of chemoradiotherapy in rectal adenocarcinoma. This study highlighted the importance of predictive criteria to chemoradiotherapy response in proposing to selected patients an alternative treatment (eg, local resection) to more radical surgery.

Redo surgery for failed colorectal or coloanal anastomosis: a valuable surgical challenge.

BACKGROUND: Redo surgery (RS) in patients with failed anastomosis is a rare procedure, and data about this surgery are lacking. The aim of this study was to examine the operative results and long-term outcomes of RS. METHODS: All patients who underwent RS between 1999 and 2008 were included. Data were analyzed from a prospective colorectal database. Failure of the procedure was defined as the inability to perform the RS or the inability to close the defunctioning stoma. RESULTS: Thirty-three patients (22 men) underwent the first surgery at a mean age of 53.4 years. Twenty-four had a colorectal anastomosis (CRA) and nine a coloanal anastomosis (CAA). The reasons for performing RS were stricture (n = 17), prior Hartmann procedure for complication on initial anastomosis (n = 6), chronic fistula (n = 5) or miscellaneous (n = 5). RS was impossible for 2 patients due to extensive adhesions. The mean operating time was 279 min (133-480) and the overall postoperative morbidity rate was 55%. The rate of anastomotic leakage and/or isolated pelvic abscess was 27%. After a mean delay of 3.9 months (0.3-16), 26 patients (79%) had a stoma closure. The mean number of stools per day was 3.2. The failure rates after new handsewn CAA and new stapled CRA were 33% (4/12) and 5% (1/19), respectively (P = .0385). The type of the former anastomosis influenced the success rate of restoring the intestinal continuity: failure rate after prior CAA was 56% and 8% after prior CRA (P = .0031). CONCLUSION: Redo surgery for failure of previous CRA or CAA is feasible but requires a demanding surgical procedure with high short-term morbidity.

Selective portal vein ligation and embolization induce different tumoral responses in the rat liver.

BACKGROUND: Portal vein ligation (PVL) and portal vein embolization (PVE) are used to enhance liver volume before hepatectomy for colorectal liver metastasis (LM). Impact of such techniques on tumor growth is not well known. This experimental study aimed to assess impact of PVE and PVL on LM growth in a murine model of colorectal LM. METHODS: Single macroscopic tumor was induced by injection of 0.5 × 10(6) DHD/K12 cells under the liver capsule of BDIX rats at day 0. Multiple microscopic tumors were obtained by intra-portal injection of 1 × 10(6) cells at day 7. At day 8, rats were divided in 3 groups: PVE group (selective 70% PVE), PVL group (selective 70% PVL); control group (sham laparotomy). Rats were sacrificed at day 37 (11 in PVE, 12 in PVL, and 10 rats in control groups). Liver volume and LM volumes were assessed. RESULTS: Nonoccluded liver volume was larger in the PVE and PVL groups vs control group (P < .0001 and P < .0001, respectively) but showed no difference in PVE vs PVL groups (P = .08). LM volume in the occluded liver was smaller in the PVE vs control groups (P = .006) and larger in the PVL vs control groups (P = .001). LM volume in the nonoccluded liver was larger in the PVE and PVL groups vs control group (P = .010 and P = .010, respectively) but showed no difference in PVE vs PVL groups (P= .878). CONCLUSION: Both PVL and PVE modify tumor growth, especially in nonoccluded lobe. These results could be of clinical importance in humans where both techniques are widely used.

Which magnetic resonance imaging findings accurately evaluate inflammation in small bowel Crohn's disease? A retrospective comparison with surgical pathologic analysis.

BACKGROUND: The aim was to evaluate the value of magnetic resonance imaging (MRI) findings in Crohn's disease (CD) in correlation with pathological inflammatory score using surgical pathology analysis as a reference method. METHODS: CD patients who were to undergo bowel resection surgery underwent MR enterography before surgery. The CD pathological inflammatory score of the surgical specimens was classified into three grades: mild or nonactive CD, moderately active CD, and severely active CD; fibrosis was also classified into three grades: mild, moderate, and severe. Mural and extramural MRI findings were correlated with pathological inflammatory and fibrosis grades. RESULTS: Fifty-three consecutive patients were included retrospectively. The mean delay between MRI and surgery was 24 days (range 1-90, median 14). The CD pathological inflammatory score was graded as follows: grade 0 (11 patients, 21%), grade 1 (15 patients, 28%), and grade 2 (27 patients, 51%). MRI findings significantly associated with pathological inflammatory grading were wall thickness (P < 0.0001), degree of wall enhancement on delayed phase (P < 0.0001), pattern of enhancement on both parenchymatous (P = 0.02), and delayed phase, (P = 0.008), T2 relative hypersignal wall (P < 0.0001), blurred wall enhancement (P = 0.018), comb sign (P = 0.004), fistula (P < 0.0001), and abscess (P = 0.049). The inflammation score correlated with the fibrosis score (r = 0.63, P = 0.0001). CONCLUSIONS: Our study identified MRI findings significantly associated with surgical pathological inflammation. These lesions are considered potentially reversible and may be efficiently treated medically. We also showed that fibrosis was closely and positively related to inflammation.

Selective portal vein embolization and colorectal liver metastases in rat: a new experimental model for tumor growth study.

BACKGROUND: Portal vein embolization (PVE) has been proposed to induce hypertrophy of liver before major resection. Because there are some concerns about the effect on tumor growth, experimental research is needed, requiring reliable small animal model. The aim was to assess technical feasibility of PVE model in rat and to report colorectal liver metastases (LM) tumor growth. METHODS: LM were induced in 40 rats by injecting DHDK12 cells into the left liver lobe. At d 7, a portography was performed through a laparotomy in 20 rats allowing the left PVE. Twenty rats without PVE served as control. All rats were sacrificed at d 30. Liver and tumor volume were calculated. RESULTS: Mortality rate was 20% (n=8). PVE was successful in 15/19 rats (79%). Compared with control rats, the left PVE induced both significant atrophy of the left lobe (3.5±0.8 versus 7.4±0.9 mm3, P<0.0001) and contralateral hypertrophy (5.8±1.1 versus 3.6±0.7 mm3, P<0.0001). LM tumor volume in the left liver was significantly decreased in PVE group compared to control, 124.4±95.7 mm3versus 231.1±90.1 mm3, P=0.008. CONCLUSION: PVE is feasible in rats with a 79% success rate. Significant hypertrophy of the remnant liver and atrophy of the embolized liver were noted suggesting the efficacy of PVE. LM tumor growth decreased significantly in the embolized lobe. Our model can be used for experimental studies evaluating tumor growth and effects of new drugs against LM in a situation that mimics the human situation before partial hepatectomy.