Comparative analyses between the early postoperative results after major liver resections of colorectal and noncolorectal cancer liver metastases

Background: Liver resections (LR) are an obligatory element in the multimodal treatment scheme of colorectal cancer liver metastases (CRCLM). Nowadays still there are debates about the benefit of any aggressive surgical approach in noncolorectal cancer liver metastases (NCRCLM) because many authors report desperately high rates of early specific post-resection complications (SPRC) followed by unsatisfactory long term results.Aim: Comparative analyses between the SPRC after major liver resections (MLR), i.e. ≥ 2 segments of CRCLM and NCRCLM for confirming or denying the hypothesis of higher risk in the group of NCRLM.Material and methods: A total of 331 MLR of benign and malignant tumors were performed between 01.01.2007 - 31.12.2014 in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital Sofia. Radical resections received 143 CRCLM patients and 58 NCRCLM patients, both synchronous and metachronous. The design of the study was `a single center` and `retrospective`. The perioperative data of these 201 patients were analyzed and finally 59 cases of CRCLM (Group 1) and 36 cases of NCRCLM (Group 2) were included in the study. All the metastases were metachronous and no significant differences in demography, comorbidity, liver function, ASA group, neoadjuvant chemotherapy and surgery specificity were detected between the two groups. Cases that were indicated for MLR were those under 65 years of age, with preserved liver function, without serious pulmonary and cardiac concomitant diseases, and estimated as ASA group ≤ III. Data about SPRC were collected and analyzed. Results: The entire early postoperative mortality rate was 3.2% (3 fatal outcomes) - 1/59 (1.7%) in group 1 and 2/36 (5.5%) in group 2. The cause of death was liver failure, sepsis and pulmonary embolism. The rate of SPRC was significantly higher in group 2, affecting 16/36 patients (44.4%) while only 18 out of all the 59 patients (30.5%) in group 1 suffered specific complications. However only 5.1% and 8.3% of the SPRC necessitated reoperations in group 1 and group 2 respectfully. The comparative analysis denied any prognostic value for the early SPRC played by the time of metastases detection, adjuvant chemotherapy, the duration of liver resection procedure and the necessity of blood transfusion. Conclusions: Both mortality and specific morbidity after MLR affected patients with ≥3 comorbid conditions which proved to be the only predictive factor for SPRC. SPRC were more frequent in group 2 (NCRCLM) but the great majority of them were solved by conservative measures, less often by interventional procedure and reoperations were indicated very rarely

Clinico-pathological prognostic factors in hematogenously disseminated colorectal cancer

Background: Ekberg`s criteria for liver resections (LR) of colorectal cancer liver metastases (CRCLM) have been accepted as a `dogma` and the procedure - as a `gold standard` since 1986. There are many wellknown predictive factors for the early and long-term results in this field of surgery. However, some of them are still a matter of debate.Aim: Study on the possible prognostic value of some clinical-pathological factors for the early and late results after major LR (≥ 2 segments) of CRCLM.Material and methods: A total of 143 radical (R0) major LR (≥ 2 segments) of synchronous and metachronous CRCLM were performed between 01.01.20007 - 31.12.2014 in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital Sofia. The design of the study was `a single center` and `retrospective`. We analyzed the data with possible predictive value - demography, comorbidity, liver function, ASA group, neoadjuvant chemotherapy, type and characteristics of the surgical procedure, pathological data (T,N,G,H) and time of detection of metastases (synchronous or metachronous). The early postoperative morbidity and mortality rates were compared with these factors looking for correlation. The long-term follow-up period was ≥ 12 months for 86 patients (60.1%).Results: The early postoperative mortality rate was 2.8% (4 cases) for the whole series. The specific morbidity rates were significantly higher in patients above 65 years of age, with ≥ 3 comorbid conditions, multivisceral resections in cases of synchronous metastases and atypical (non-anatomical) LR. The majority of CRCLM cases were ≥ Т2, N (+) positive and G2-3. Unfavorable prognostic factors were the detection of metachronous lesions earlier than 12 months after a curative previous resection especially on the basis of adequate chemotherapy.Conclusions: The knowledge on prognostic factors in patients with CRCLM as well as on indications and contraindications helps the correct preoperative judgment on choosing the right and appropriate type and volume of surgical procedures

Investigation of mm-wave RTD based amplifiers

This work explores the applicability of Resonant Tunnelling Diodes as active elements in two different amplifier configurations in the range 25 GHz – 35 GHz, with a view of implementing scaled versions at W-band and beyond, as frontend narrow-band low-noise amplifiers. On-wafer S-parameter measurements are used to represent devices in simulation software for increased fidelity. Initial results are promising, showing close to 10 dB gain at 30 GHz

Non-Colorectal Liver Metastases - Where Are the Limits of a Reasonable Aggressive Surgical Approach in the Multimodal Treatment Scheme?

Background: Resection of non-colorectal liver metastases (NCRLM) is one of the recent fields in hepatic surgery. It was just 10-12 years ago when those procedures were totally denied as `risky` and `useless` and therefore, they were performed as an exception. Aim: The aim of this paper is to present analyses of early and late postoperative results in our series of resections of NCRLM, discussion of the indications for surgery and evaluation of the possible benefit of surgery as an element of multimodal treatment scheme. Materials and Methods: The study design was a single-center retrospective and prospective for a 9-year period (January 1, 2007-December 31, 2015). A total of 62 patients received R0 resections of metachronous and synchronous NCRLM. Metastatic pancreatic and gastric cancer cases predominated (n=49, 80.3%). The indications for aggressive surgery included age ≤ 60(65) years, absence of serious concomitant diseases, ASA ≤ III, no data of other distant organ involvement, no peritoneal lesions, no local recurrence (in metachronous cases) and resectable primary tumor (in synchronous cases). The early postoperative results were analyzed and outpatient follow-up was done every 3 months. Disease-free survival (DFS) and overall survival (OAS) rates were studied. Results: The early postoperative mortality rate was 4.2% in the whole series (2 fatal outcomes in gastric and 1 in pancreatic NCRLM). The specific morbidity rate was very high (N=33, 54.1%) and more often ascertained after multivisceral resections of synchronous NCRLM but 84.8% of them were treated by conservative or interventional methods. Reoperation was performed on 5 patients (15.2%). Fifty-six patients (91.8%) were followed for ≥12 months or until the patient`s death was registered. DFS (8.9-22.4 months) and OAS rates (10.7-57.3 months) varied in broad range and demonstrated statistical dependence on the primary tumor location, time of detection and „N`, „G` and `R` categories. Conclusion: Indicated and reasonable resections of synchronous and metachronous NCRLM had morbidity and mortality rates comparable to that of other multivisceral resections and they lead to a positive impact on the survival rates and the quality of life

Specific Postoperative Complications After Pancreatic Resections - Structure, Predictors, Prevention and Treatment in a Single Institution Series of 173 Cases

Introduction: The morbidity rate after pancreatic resections (PR) remains oppressively high and reaches up to 50% in some current studies of world-leading centres and schools. Specific complications are still one of the main problems because they deteriorate the patient`s quality of life, deteriorate the prognosis, prolong the hospital stay and the trеatment expenses exceed by more than 3 times the cost of uncomplicated cases. Aim: The aim of this paper is to conduct an analysis of the early postoperative results after PR and a study on the structure, predictive factors, treatment and prevention of early specific complications. Materials and Methods: A total of 173 PR (135 duodenohemipancreatectomies and 38 left pancreatectomies) have been performed at the authors` institution since January 1, 2007 till December 31, 2015. The study design was single-center, retrospective and randomized. Exclusion criteria were the following: (1) a benign pancreatic disease and/or a neighboring tumor of a different than pancreatic primary site that necessitated PR; (2) R1,2 positive resections; (3) synchronous 1-metastases, i.e. single-stage multivisceral resections; (4) age ≥ 70 years; (5) the presence of ≥ 3 comorbid conditions. Finally, we selected 108 cases and collected and analyzed perioperative data, specific characteristics of the procedure (duration, blood loss, technical aspects of the anastomosis, protective drainages) and the early postoperative results. Results: The early (within 30 days after surgery) mortality and specific morbidity rates were 3.7% (4 cases) and 31.5% (42 complications in 34 patients), respectively. Reoperation was indicated in 3 cases (2.8%) while the remaining 31 patients were treated conservatively and/or by interventional procedures. We performed correlative analyses for dependence between: (1) mortality and specific morbidity rates on the one hand and (2.1.) preoperative condition, respectively adequate preparation, and jaundice cure on the other; (2.2.) type and technique of anastomoses; (2.3.) pancreatic duct diameter; (2.4.) quantity of operative blood loss. Conclusion: In our series of right and left PR we found prognostic value of the preoperative patient`s condition, anastomosis construction and operative blood loss for a specific morbidity