The value of 18F-FDG PET/CT for assessing the response to neoadjuvant therapy in locally advanced rectal cancer.

PURPOSE: Neoadjuvant radiochemotherapy (RCT) is an accepted treatment for locally advanced rectal cancer (LARC) that improves surgical outcomes. If a pathological complete response is achieved, conservative surgery can be considered. The objective of our study was to assess the reliability of (18)F-FDG PET/CT for evaluating the response to neoadjuvant RCT in LARC. METHODS: We prospectively studied 41 patients diagnosed with LARC and candidates for neoadjuvant RCT. PET/CT was performed before RCT and again 7 weeks later. A visual and semiquantitative analysis was carried out. The pathological response was classified according to the Mandard tumour regression grade (TRG). We analysed: (a) the relationship between TRG and the result of the posttreatment PET/CT scan, and (b) the correlation between the percentage of pathological response and the percentage decrease in SUVmax according to the response index (RI). RESULTS: The mean SUVmax of the rectal lesions at diagnosis was 13.6 and after RCT 3.96. The mean RI was 65.32 %. Sensitivity was 88.88 %, specificity 92.86 %, positive predictive value 96 %, negative predictive value 81 %. Of the 41 patients, 8 had TRG I (all negative PET/CT); 6 had TRG II (5 negative, 1 positive PET/CT); 16 had TRG III (13 positive, 3 negative PET/CT); 9 had TRG IV (all positive PET/CT); 2 had TRG V (all positive PET/CT). Of the 14 patients classified as responders (TRG I, II), 13 (92.86 %) had negative PET/CT. Of the 27 patients classified as nonresponders (TRG III-V), 24 (88.88 %) had positive PET/CT. Differences were statistically significant (p < 0.0001). The RI in responders was 79.9 % and in nonresponders was 60.3 %. Differences were statistically significant (p < 0.037). CONCLUSION: PET/CT is a reliable technique for assessing response to neoadjuvant RCT in LARC, with a view to considering more conservative surgical treatment. The combination of the visual and semiquantitative analysis increases the diagnostic validity of PET/CT.

Characteristics and prognosis of jejunoileal gastrointestinal stromal tumours (GISTs) in the era of imatinib: a comparative study with gastric GISTs.

BACKGROUND: Gastrointestinal stromal tumours (GISTs) located in the jejunum or ileum (JI-GIST) are considered worse prognosis compared to those of gastric (G-GIST) location. It has been suggested that this dogma should be revised. The aim of this study was to describe the characteristics of jejunoileal GISTs and its prognosis and to compare them with G-GISTs in the era of imatinib. METHODS: We retrospectively reviewed the clinical histories of all the patients diagnosed with GISTs between January 2000 and November 2016: Clinical and pathological data, as recurrence, metastatic state, disease-free survival (DFS) as well as overall survival (OS) rates of patients were reviewed. RESULTS: JI-GIST patients comprise 29 cases (37.7%). Compared to G-GIST, JI-GIST patients had undergone emergency surgery more frequently (37.9% vs. 10.4%, p = 0.007). According to the NIH-Fletcher classification, the low or very-low risk group represents 17.2% of JI-GISTs as opposed to 37.6% of G-GISTs (p < 0.005). When the AFIP-Miettinen system was used the low or very-low group represented 17.2% of JI-GISTs vs. 58.4% in the G-GISTs group (p < 0.001). Both local recurrence (24.1% vs. 12.5%, p < 0.05) and metastatic rate (34.5% vs. 22.9%, p < 0.05) were higher in the JI-GIST group than in G-GIST. 5- and 10-year DFS and 10-year OS rate were lower for JI-GIST (54.5% and 39.6% vs. 77.2% and 60.8%, and 57.9% vs. 65%, respectively, p < 0.05). CONCLUSIONS: The observed differences between both groups in DFS and OS rates at long term could be attributed to the effect of imatinib.

Incidental Gastrointestinal Stromal Tumors (GISTs) and Bariatric Surgery: A Review.

The number of bariatric procedures has increased notably, with incidental findings such as gastrointestinal stromal tumors (GISTs) being observed in 2%. The number of studies dealing with incidental findings during bariatric surgery (BS), especially GISTs, is scarce. This review aims to summarize the evidence about GIST diagnosis during BS, and to establish recommendations for the management and follow-up of these patients. A systematic literature search from January 2000 to March 2020 was performed. Retrospective cohort studies, case series, case reports, reviews, and conference abstracts were considered eligible. The present systematic review focused on a descriptive analysis of the data included in the articles selected. The calculated incidence was 0.65%. A change in operative plan was observed in 5% of the cases. In 98% of the cases, GISTs were gastric, with a mean size of 10.3 mm. The mitotic index was < 5 in 99%. Accordingly, all patients were classified as having a very low or low risk of recurrence. R0 resection was achieved in 100% of cases. The incidence of GISTs in patients with MO submitted to BS is considerably higher than in the general population. The diagnosis is related to the depth of preoperative work, the exhaustiveness of the intraoperative examination, and the meticulousness of the histopathological analysis. Although GISTs have a low risk of recurrence and it was previously unnecessary to modify the surgical technique, we recommend that bariatric surgeons are aware of the diagnosis and management of incidental GISTs.

Randomized clinical trial comparing laparoscopic and open surgery in patients with rectal cancer.

BACKGROUND: The laparoscopic treatment of rectal cancer is controversial. This study compared surgical outcomes after laparoscopic and open approaches for mid and low rectal cancers. METHODS: Some 204 patients with mid and low rectal adenocarcinomas were allocated randomly to open (103) or laparoscopic (101) surgery. The surgical team was the same for both procedures. Most patients had stage II or III disease, and received neoadjuvant therapy with oral capecitabine and 50-54 Gy external beam radiotherapy. RESULTS: Sphincter-preserving surgery was performed in 78.6 and 76.2 per cent of patients in the open and laparoscopic groups respectively. Blood loss was significantly greater for open surgery (P < 0.001) and operating time was significantly greater for laparoscopic surgery (P = 0.020), and return to diet and hospital stay were longer for open surgery. Complication rates, and involvement of circumferential and radial margins were similar for both procedures, but the number of isolated lymph nodes was greater in the laparoscopic group (mean 13.63 versus 11.57; P = 0.026). There were no differences in local recurrence, disease-free or overall survival. CONCLUSION: Laparoscopic surgery for rectal cancer has a similar complication rate to open surgery, with less blood loss, rapid intestinal recovery, shorter hospital stay, and no compromise of oncological outcomes.

Additional malignancies in patients with gastrointestinal stromal tumors (GIST): incidence, pathology and prognosis according to a time of occurrence-based classification.

BACKGROUND: The aim of the study is to clarify if a classification based on the time of occurrence of associated malignancies in GIST patients can help in the understanding of the clinical controversies observed in these patients. METHODS: We retrospectively reviewed all the patients diagnosed with GIST tumors between January 1999 and October 2016. They were divided into GIST patients associated with other tumors (A-GIST) and those not associated (NA-GIST). A-GIST patients were also divided into four types according to the proposed classification. RESULTS: Of 104 GIST patients, 32 (30.7%) (A-GIST group) had at least one additional primary malignancy. The most frequent location of the associated malignancy was the GI tract (26%). Compared to NA-GIST, A-GIST were more often asymptomatic with a lower risk of recurrence. The main cause of death in NAGIST was GIST itself, being associated tumors the main cause of death in A-GIST group. No differences were found in DFS and OS between A-GIST and NA-GIST. CONCLUSIONS: The use of the proposed classification classifies GIST patients with associated malignancies in different subtypes that differ substantially in terms of incidence, type of neoplasms associated, cause of the association and prognosis.

Utility of Basal Regional Oximetry Saturation for the Diagnosis of Acute Tubular Necrosis in the Early Postoperative Period Following Kidney Transplantation.

INTRODUCTION: Adequate perfusion and oxygenation to a renal graft after transplantation are essential for its viability. Regional renal oximetry (RSrO2) through near-infrared spectroscopy shows real-time oxygen content of the graft. METHODS: A prospective study was conducted. We enrolled consecutive patients undergoing renal transplant from deceased donors from January 2015 to February 2016. RSrO2 was continuously measured for 24 hours, analyzed, and correlated with other clinical data such as hemoglobin, mixed central venous oxygen saturation (ScvO2), blood pressure, central venous pressure, diuresis, and blood lactate. Severity disease scales, cold and warm ischemia times were also measured, as well as the pulsatility index (PI) and resistive index (RI) by Doppler-dúplex ultrasound (DUS) at 24 hours. A statistical analysis with IBM SPSS version 22 (IBM, Armonk, NY) using a Pearson correlation was carried out. RESULTS: RSrO2 could anticipate serious arterial and bleeding events showing a maintained decrease >10% from basal data. A significant correlation was found between RSrO2 with lactate at 8 and 24 hours (P = .005 and P = .000 respectively), as well as with initial diuresis at hour 3 (P = .010), initial ScvO2 (P = .010), Sequential Organ Failure Assessment (P = .015), and warm ischemia (P = .035). A significant correlation was also detected between cold ischemia, RI, and diuresis (P = .037 and P = .049 respectively). No correlation was found between RSrO2 and DUS data. CONCLUSION: RSrO2 is a useful tool for initial kidney transplant grafts monitoring and could give early warnings regarding bleeding and arterial thrombosis. RSrO2 is found to have a correlation with initial diuresis, blood lactate, and ScvO2. No matching data with Doppler was found.

Stapling Versus Hand Suture for Gastroenteric Anastomosis in Roux-en-Y Gastric Bypass: a Randomized Clinical Trial.

BACKGROUND: Different anastomotic techniques have been evaluated during a laparoscopic Roux-en-Y gastric bypass (RYGB); however, no techniques have proven to be better than any other regarding complications and the percentage of weight loss (excess weight loss (%EWL)), and there are few controlled prospective studies to compare them. METHODS: A randomized, prospective study was conducted in 238 patients undergoing RYGB for morbid obesity between July 2008 and September 2012 to compare the early and late postoperative complications between the two surgical techniques: gastrojejunal hand-sutured anastomosis (HSA) and circular-stapled anastomosis (CSA). Minimum follow-up was 24 months. RESULTS: The two groups of patients were similar for demographic data and preoperative comorbidities. There were no significant differences between the surgical techniques regarding %EWL at 3, 12, and 24 months. The patients with CSA had a greater frequency of postoperative gastrointestinal bleeding (GIB) (4.2 vs. 0%, p = 0.024) and surgical wound infection (11.1 vs. 3.4%, p = 0.025) than the patients with HSA, with no significant differences in the other early complications. There were no significant differences in either group for late complications (gastrojejunal anastomosis (GJA) stricture, marginal ulcer, GJA perforation, bowel obstruction, and eventration). No significant differences were observed in operative time, rate of reoperation and postoperative length of hospital stay. CONCLUSIONS: HSA and CSA were techniques with similar safety and effectiveness in our study. HSA had a lower rate of bleeding complications and surgical wound infection, although it does require greater experience in laparoscopic hand suturing.

Laparoscopic gastric bypass in the treatment of morbid obesity. Preliminary results of a new technique.

INTRODUCTION: Gastric bypass is one of the most commonly used surgical techniques for the management of morbid obesity. It is usually done as an open surgery procedure, and in recent years surgeons have begun to perform it via the laparoscopic approach. The aim of this paper is to describe our surgical technique for laparoscopic gastric bypass (LGBP) and present the short-term results. MATERIALS AND METHODS: Between January 2000 and January 2002 we operated on 50 patients with morbid obesity who met criteria for bariatric surgery. The patients had a mean age of 34 years and a body mass index (BMI) of 47. RESULTS: Conversion was necessary in 4 of the 50 patients (8%). Mean operating time was 181 min, with a difference of 60 min between the first 10 and last 10 cases. There was a 26% rate of complications, 14% of which were early (%<% 30 days) and 12% late (%>%30 days). Mean hospital stay was 4.5 days. CONCLUSION: LGBP is a technique with good short-term results as far as weight loss is concerned, although it has one of the most complex learning curves in laparoscopic surgery. Surgeons who regard gastric bypass as the technique of choice for the surgical management of morbid obesity should consider performing it via the laparoscopic approach.

Sexual dimorphism in clock genes expression in human adipose tissue.

BACKGROUND: This study was carried out to investigate whether sex-related differences exist in the adipocyte expression of clock genes from subcutaneous abdominal and visceral fat depots in severely obese patients. METHODS: We investigated 16 morbidly obese patients, eight men and eight women (mean age 45 ± 20 years; mean BMI 46 ± 6 kg/m(2)), undergoing laparoscopic gastric bypass surgery. Biopsies were taken as paired samples [subcutaneous and visceral adipose tissue (AT)] at the beginning of the surgical process at 11:00 h in the morning. Metabolic syndrome features such as waist circumference, plasma glucose, triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were also studied. The expression of clock genes (PER2, BMAL1, and CRY1) was measured by quantitative real-time PCR, Western blot, and immunohistochemical analysis. RESULTS: Gene expression was significantly higher in women than in men for the three genes studied in both ATs (P < 0.05). In visceral fat, these differences were more marked. (P < 0.001). Western blot analysis partially confirmed these results since statistical differences were observed for PER2 in both ATs and for CRY1 in subcutaneous adipose tissue. There were no differences in BMAL1 protein expression. Interestingly, clock gene expression level was correlated with LDL-C and HDL-C (P < 0.05). Moreover, we found significant associations with body fat mass in women and with age in men. CONCLUSIONS: Clock genes expression is sex dependent in human adipose tissue from morbidly obese subjects and correlates to a decreased in metabolic syndrome-related traits. These preliminary results make necessary to go deep into the knowledge of the molecular basis of the sexual dimorphism in chronobiology.