Valley Pseudospin Polarized Evanescent Coupling between Microwave Ring Resonator and Waveguide in Phononic Topological Insulators.

A coupled ring-waveguide structure is at the core of bosonic wave-based information processing systems, enabling advanced wave manipulations such as filtering, routing, and multiplexing. However, its miniaturization is challenging due to momentum conservation issues in rings with larger curvature that induce significant backscattering and radiation leakage and hampering stable operation. Here, we address it by taking an alternative approach of using topological technology in wavelength-scale and microwave ring-waveguide coupled systems built in nanoengineered phononic crystals. Our approach, which leverages pseudospin conservation in valley topological systems, eliminates phonon backscattering and achieves directional evanescent coupling. The resultant hypersonic waves in the tiny ring exhibit robust transport and resonant circulation. Furthermore, the ring-waveguide hybridization enables critical coupling, where valley-dependent ring-waveguide interference blocks the transmission. Our findings reveal the capability of topological phenomena for managing ultrahigh-frequency phonons in nano/microscale structures and pave the way for advanced phononic circuits in classical and quantum signal processing applications.

Risk factors for pulmonary complications after colorectal cancer surgery: a Japanese multicenter study.

PURPOSE: Pulmonary complications (PC) are a serious condition with a 20% mortality rate. However, few reports have examined risk factors for PC after colorectal surgery. This study investigated the frequency, characteristics, and risk factors for PC after colorectal cancer surgery. METHODS: Between January 2016 and December 2022, we retrospectively reviewed 3979 consecutive patients who underwent colorectal cancer surgery in seven participating hospitals. Patients were divided into patients who experienced PC (PC group, n = 54) and patients who did not (non-PC group, n = 3925). Clinical and pathological features were compared between groups. RESULTS: Fifty-four patients (1.5%) developed PC, of whom 2 patients (3.7%) died due to PC. Age was greater (80 years vs 71 years; p < 0.001), frequency of chronic obstructive pulmonary distress was greater (9.3% vs 3.2%; p = 0.029), performance status was poorer (p < 0.001), the proportion of underweight was higher (42.6% vs 13.4%, p < 0.001), frequency of open surgery was greater (24.1% vs 9.3%; p < 0.001), and blood loss was greater (40 mL vs 22 mL; p < 0.001) in the PC group. Multivariate analysis revealed male sex (odds ratio (OR) 2.165, 95% confidence interval (CI) 1.176-3.986; p = 0.013), greater age (OR 3.180, 95%CI 1.798-5.624; p < 0.001), underweight (OR 3.961, 95%CI 2.210-7.100; p < 0.001), and poorer ASA-PS (OR 3.828, 95%CI 2.144-6.834; p < 0.001) as independent predictors of PC. CONCLUSION: Our study revealed male sex, greater age, underweight, and poorer ASA-PS as factors associated with development of PC, and suggested that pre- and postoperative rehabilitation and pneumonia control measures should be implemented for patients at high risk of PC.

Prognostic value of lymph node distribution after laparoscopic colectomy with Japanese D3 dissection.

PURPOSE: Positive pathologic lymph nodes in colorectal cancer represent an important prognostic indicator. Whether lymph node distribution or the number of metastatic nodes is more strongly associated with survival prediction remains controversial. METHODS: Among 3449 colorectal cancer surgeries performed at Nagasaki University Hospital and five affiliated institutions from April 2016 to March 2022, we investigated 604 patients who underwent laparoscopic radical resection and were diagnosed with pathological stage III cancer. Patients were divided into two groups according to whether they had central vessel metastasis (LND3 group, n=42) or not (LND1/2 group, n=562). After adjusting for background factors using propensity score matching, the LND3 group included 42 patients and the LND1/2 group included 40 patients. Patient background characteristics and prognosis were compared between these two groups. RESULTS: Before matching, frequencies of right-side colon cancer (64.3% vs 38.1%, p=0.001), multivisceral resection (11.9% vs 4.4%, p=0.039), clinical N2 status (40.5% vs 22.6%, p=0.032), and pathological N2 (73.8% vs 22.6%, p<0.001) were all greater, and the number of lymph nodes retrieved was higher (24 vs 19, p=0.042) in the LND3 group. After matching, no differences in any clinical factors were evident between groups. Five-year RFS (44.8% vs 77.1%, p=0.004) and OS (43.1% vs 83.2%, p<0.001) were worse in the LND3 group. Adjuvant chemotherapy improved RFS (adjuvant chemotherapy (+) vs adjuvant chemotherapy (-): 62.1% vs 27.7%, p=0.047) in the LND3 group. CONCLUSION: LND3-positive patients show poorer prognosis than LND1/2 patients and should be treated with an appropriate perioperative treatment strategy.

Correlations of age with clinicopathological features, perioperative outcomes and the prognosis in patients with colorectal cancer: a Japanese multicenter study.

PURPOSE: Colorectal cancer is not common in patients under 40 years old, and its associations with clinical features and the prognosis remain uncertain. METHODS: Using a multicenter database, we retrospectively reviewed 3015 patients who underwent colorectal surgery between 2016 and 2021. Patients were divided by age into those < 40 years old (young; n = 52), 40-54 years old (middle-aged; n = 254) and > 54 years old (old; n = 2709). We then investigated age-related differences in clinicopathological features, perioperative outcomes and the prognosis. RESULTS: The proportion of young patients increased annually from 0.63% in 2016 to 2.10% in 2021. Female patients were more frequent, the performance status was better, tumors were larger, clinically node-positive and poorly differentiated adenocarcinomas were more frequent, postoperative complications were less frequent, and the hospital stay was shorter in young patients than in older patients. Young age was an independent predictor of a low risk of postoperative complications (odds ratio, 0.204; 95% confidence interval, 0.049-0.849; p = 0.028). With pathologically node-positive status, adjuvant chemotherapy was more frequent in young patients (100%) than in middle-aged (73.7%) or old (51.8%) patients (p < 0.001), and the 3-year relapse-free survival was better in the young group than in others. CONCLUSION: Despite higher rates of advanced tumors in younger patients, adequate adjuvant chemotherapy appears to improve the relapse-free survival.

Effect of the lymphocyte-to-monocyte ratio on the prognosis of patients with obstructive colorectal cancer with a colonic stent: a retrospective multicenter study in Japan.

PURPOSE: The prognostic value of the lymphocyte-to-monocyte (LMR) ratio has been reported for various cancers, including colorectal cancer (CRC). The insertion of colonic stents is considered effective for patients with surgically indicated obstructive CRC, but their LMR can vary depending on factors such as inflammation associated with stent dilation and improvement of obstructive colitis. However, the usefulness of the LMR in patients with obstructive CRC and colonic stents and the optimal timing for its measurement remain unclear. We conducted this study to investigate the relationship between the pre-stent LMR and the mid-term prognosis of patients with obstructive CRC and stents as a bridge to surgery (BTS). METHODS: The subjects of this retrospective multicenter study were 175 patients with pathological stage 2 or 3 CRC. Patients were divided into a low pre-stent LMR group (n = 87) and a high pre-stent LMR group (n = 83). RESULTS: Only 3-year relapse-free survival differed significantly between the low and high pre-stent LMR groups (39.9% vs. 63.6%, respectively; p = 0.015). The pre-stent LMR represented a prognostic factor for relapse-free survival in multivariate analyses (hazard ratio 2.052, 95% confidence interval 1.242-3.389; p = 0.005), but not for overall survival. CONCLUSIONS: A low pre-stent LMR is a prognostic factor for postoperative recurrence in patients with obstructive CRC and a colonic stent as a BTS.

Short-term outcomes after laparoscopic colorectal cancer surgery in patients over 90 years old: a Japanese multicenter study.

BACKGROUND: The effect of laparoscopic surgery on short-term outcomes in colorectal cancer patients over 90 years old has remained unclear. METHODS: We reviewed 87 colorectal cancer patients aged over 90 years who underwent surgery between 2016 and 2022. Patients were divided into an open surgery group (n = 22) and a laparoscopic surgery group (n = 65). The aim of this study was to investigate the effect of laparoscopic surgery on postoperative outcome in elderly colorectal cancer patients, as compared to open surgery. RESULTS: Seventy-eight patients (89.7%) had comorbidities. Frequency of advanced T stage was lower with laparoscopic surgery (p = 0.021). Operation time was longer (open surgery 146 min vs. laparoscopic surgery 203 min; p = 0.002) and blood loss was less (105 mL vs. 20 mL, respectively; p < 0.001) with laparoscopic surgery. Length of hospitalization was longer with open surgery (22 days vs. 18 days, respectively; p = 0.007). Frequency of infectious complications was lower with laparoscopic surgery (18.5%) than with open surgery (45.5%; p = 0.021). Multivariate analysis revealed open surgery (p = 0.026; odds ratio, 3.535; 95% confidence interval, 1.159-10.781) as an independent predictor of postoperative infectious complications. CONCLUSIONS: Laparoscopic colorectal resection for patients over 90 years old is a useful procedure that reduces postoperative infectious complications.

Effect of adjuvant chemotherapy after curative resection of colorectal cancer peritoneal metastasis.

PURPOSE: Several guidelines have recommended surgical resection for localized peritoneal metastases, but the prognosis remains poor. In addition, the efficacy of adjuvant chemotherapy (AC) after curative resection is under debate. The present study compared long-term outcomes between curative and non-curative resection and evaluated the effects of AC after curative resection. METHODS: Using a multicenter database, we retrospectively reviewed 123 colorectal cancer patients with peritoneal metastases between April 2016 and December 2021. Of these patients, 49 underwent curative resection, and 74 underwent non-curative resection. RESULTS: The frequency of broad metastases was lower in the curative resection group (8.2%) than in the non-curative resection group (43.2%, p < 0.001). Among all patients, 5-year overall survival rate was higher in the curative resection group (43.0%) than in the non-curative resection group (7.3%, p = 0.004). Among patients who underwent curative resection, 5-year overall survival rate was significantly higher in the AC group (48.2%) than in the non-AC group (38.1%, p = 0.037). Multivariate analysis of all patients revealed pathological N status and non-curative resection as independent predictors of overall survival. In patients who underwent curative resection, advanced age was an independent predictor of relapse-free survival, and AC was an independent predictor of overall survival. CONCLUSION: This multicenter study of colorectal cancer patients with peritoneal metastases revealed that prognosis was more favorable for curable cases than for non-curable cases. Prognosis was more favorable in the AC group than in the non-AC group after curative resection.

Usefulness of the endoscopic surgical skill qualification system for laparoscopic colectomy for transverse colon cancer: a Japanese multicenter analysis.

PURPOSE: Laparoscopic colectomy for transverse colon cancer (TCC) can be technically demanding due to the anatomical complexity of the region. In Japan, the Endoscopic Surgical Skill Qualification System (ESSQS) was established to improve the skill of laparoscopic surgeons and further develop surgical teams. We examined the safety and feasibility of laparoscopic colectomy for TCC and evaluated the effects of the Japanese ESSQS in facilitating this approach. METHODS: We retrospectively reviewed 136 patients who underwent laparoscopic colectomy for TCC between April 2016 and December 2021. Patients were divided into an ESSQS-qualified surgeon group (surgery performed by an ESSQS-qualified surgeon, n = 52) and a non ESSQS-qualified surgeon (surgery performed by a non ESSQS-unqualified surgeon, n = 84). Clinicopathological and surgical features were compared between groups. RESULTS: Postoperative complications occurred in 37 patients (27.2%). The proportion of patients who developed postoperative complications was lower in the ESSQS-qualified surgeon group (8.0%) than that in the non ESSQS-qualified surgeon group (34.5%; p < 0.017). Multivariate analysis revealed "Operation by ESSQS-qualified surgeon surgeon" (odds ratio (OR) 0.360, 95% confidence interval (CI) 0.140-0.924; p = 0.033), blood loss (OR 4.146, 95% CI 1.688-10.184; p = 0.002), and clinical N status (OR 4.563, 95% CI 1.814-11.474; p = 0.001) as factors independently associated with postoperative complications. CONCLUSION: The present multicenter study confirmed the feasibility and safety of laparoscopic colectomy for TCC and revealed that ESSQS-qualified surgeon achieved better surgical outcomes.

Efficacy of left colic artery preservation with D3 lymph node dissection in laparoscopic surgery for advanced sigmoid and rectal cancer.

PURPOSE: For advanced left colon cancer, lymph node dissection at the root of the inferior mesenteric artery is recommended. Whether the left colic artery (LCA) should be preserved or resected remains contentious. METHODS: The 367 patients who underwent laparoscopic sigmoidectomy or anterior resection and who were pathologically node-positive were reviewed. Patients were divided into LCA-preserving group (LCA-P, n = 60) and LCA-non-preserving group (LCA-NP, n = 307). Propensity score matching was applied to minimize selection bias and 59 patients were matched. RESULTS: Before matching, the rates of poor performance status and cardiovascular disease were higher in the LCA-P group (p < 0.001). After matching, operation time was longer (276 vs. 240 min, p = 0.001), the frequency of splenic flexure mobilization (62.7% vs. 33.9%, p = 0.003) and lymphovascular invasion (84.7% vs. 55.9%, p = 0.001) was higher in the LCA-P group. Severe postoperative complications (CD ≥ 3) occurred only in the LCA-NP group (0% vs. 8.4%, p = 0.028). The median follow-up period was 38.5 months (range 2.0-70.0 months). The 5-year RFS rates (67.8% vs. 66.0%, p = 0.871) and OS rates (80.4% vs. 74.9%, p = 0.308) were comparable between the groups. CONCLUSIONS: Laparoscopic LCA-sparing surgery for left-sided colorectal cancer reduces the risk of severe complications and offers a favorable long-term prognosis.

Effect of oxaliplatin in elderly colon cancer patients with pathological T4 and/or N2 disease: a multicenter, propensity score-matched analysis.

PURPOSE: Although adjuvant chemotherapy (AC) using fluoro-pyrimidine and oxaliplatin (FU + oxaliplatin) is recommended after curative resection for locally advanced colon cancer patients, several randomized controlled trials have shown no additional effect of oxaliplatin in patients aged ≥ 70 years. Here, we examined the effectiveness of FU + oxaliplatin on the long-term outcome of old patients with a high risk of recurrence. METHODS: This multicenter, retrospective study included 346 colon cancer patients diagnosed with pathological T4 and/or N2 disease from 2016 to 2020. They were divided into an old group (≥ 70 years, n = 197) and a young group (< 70 years, n = 167). Propensity score matching was used to minimize selection bias, and 126 patients per group were matched. RESULTS: Before matching, the rates of poor performance status (p < 0.001) and the presence of comorbidities (76.1% vs. 47.9%, p < 0.001) were higher in the old group. Although all baseline factors were similar between groups, after matching, the AC rate was lower in the old group (45.2% vs. 65.1%, p = 0.002). In the old group, relapse-free (82.2% vs. 55.6% and 69.6%, p < 0.05) and overall survival (83.1% vs. 80.0% and 44.4%, p < 0.05) rates were significantly higher in the AC patients with FU + oxaliplatin than in the AC patients with only FU and the non-AC patients. CONCLUSION: The selected old colon cancer patients with a high risk of recurrence gained an additional benefit with respect to prognosis from FU + oxaliplatin as AC.

Underbody blankets have a higher heating effect than overbody blankets in lithotomy position endoscopic surgery under general anesthesia: a randomized trial.

BACKGROUND: Surgery under general anesthesia results in temperature decrease due to the effect of anesthetics and peripheral vasodilation on thermoregulatory centers. Perioperative temperature control is therefore an issue of high importance. In this study, we aimed to compare the warming effect of underbody and overbody blankets in patients undergoing surgery in the lithotomy position under general anesthesia. METHODS: From September 2018 to October 2019, 99 patients undergoing surgery for colorectal cancer in the lithotomy position were included in this randomized controlled trial and assigned to the intervention group (underbody blanket) or control group (overbody blanket). RESULTS: The central temperature was significantly higher in the underbody blanket group than in the overbody blanket group at 90 min after the beginning of the surgery (p = 0.02); also in this group, the peripheral temperature was significantly higher 60 min after the beginning of the surgery (p = 0.02). Regarding postoperative factors, the underbody blanket group had a significantly lower frequency of postoperative shivering (p < 0.01) and a significantly shorter postoperative hospital stay (p = 0.04) than the overbody blanket group. CONCLUSIONS: We recommend the use of underbody blankets for intraoperative temperature control in patients undergoing surgery in the lithotomy position under general anesthesia. Underbody blankets showed improved rise and maintenance of central and peripheral temperature, decreased the incidence of postoperative shivering, and shortened the postoperative length of hospital stay.

Effect of endoscopic surgical skill qualification system for laparoscopic multivisceral resection: Japanese multicenter analysis.

BACKGROUND: The efficacy of laparoscopic multivisceral resection (Lap-MVR) has been reported by several experienced high-volume centers. The Endoscopic Surgical Skill Qualification System (ESSQS) was established in Japan to improve the skill of laparoscopic surgeons and further develop surgical teams. We examined the safety and feasibility of Lap-MVR in general hospitals, and evaluated the effects of the Japanese ESSQS for this approach. METHODS: We retrospectively reviewed 131 patients who underwent MVR between April 2016 and December 2019. Patients were divided into the laparoscopic surgery group (LAC group, n = 98) and the open surgery group (OPEN group, n = 33). The clinicopathological and surgical features were compared between the groups. RESULTS: Compared with the OPEN group, BMI was significantly higher (21.9 vs 19.3 kg/m2, p = 0.012) and blood loss was lower (55 vs 380 ml, p < 0.001) in the LAC group. Operation time, postoperative complications, and postoperative hospital stay were similar between the groups. ESSQS-qualified surgeons tended to select the laparoscopic approach for MVR (p < 0.001). In the LAC group, ESSQS-qualified surgeons had superior results to those without ESSQS qualifications in terms of blood loss (63 vs 137 ml, p = 0.042) and higher R0 resection rate (0% vs 2.0%, p = 0.040), despite having more cases of locally advanced tumor. In addition, there were no conversions to open surgery among ESSQS-qualified surgeons, and three conversions among surgeons without ESSQS qualifications (0% vs 15.0%, p = 0.007). Multivariate analysis revealed blood loss (odds ratio 1.821; 95% CI 1.324-7.654; p = 0.010) as an independent predictor of postoperative complications. Laparoscopic approach was not a predictive factor. CONCLUSIONS: The present multicenter study confirmed the feasibility and safety of Lap-MVR even in general hospitals, and revealed superior results for ESSQS-qualified surgeons.

Short- and mid-term outcomes of laparoscopic colorectal surgery in patients ≥ 85 years old: a multicenter study using a propensity score-matched analysis.

PURPOSE: The number of laparoscopic surgeries for colorectal cancer (CRC) in elderly patients has been increasing. We examined the short- and mid-term outcomes of laparoscopic surgery for CRC in oldest-old patients (≥ 85 years old) compared with the outcomes in younger patients (< 85 years old). METHODS: We retrospectively reviewed primary tumor resection for CRC from April 2015 to December 2020 at six hospitals. Short- and mid-term outcomes were compared after propensity score matching. RESULTS: From the 1374 patients, 126 matched pairs were selected. In the matched cohort, the duration of postoperative hospital stay was longer in the oldest-old patients than in the younger patients (15 days vs. 12 days, p = 0.001). There were no significant differences between the groups in the rate of Clavien-Dindo grade ≥ 2 postoperative complications (21.4% vs. 15.1%, p = 0.254). The oldest-old patients showed a poorer overall survival (OS) than the younger patients (3-year OS, 79.9% vs. 93.5%, p = 0.005) but comparable recurrence-free survival (RFS) (3-year RFS, 72.2% vs. 81.6%, p = 0.530) and cancer-specific survival rates (CSS) (3-year CSS, 90.1% vs. 99.0%, p = 0.124). CONCLUSION: Laparoscopic surgery for CRC in oldest-old patients was performed safely with comparable short-term outcomes to those in younger patients. Although the OS was poorer in the oldest-old patients than in the younger patients, the oncological mid-term outcomes were comparable. Laparoscopic surgery for CRC can be considered acceptable as a treatment in oldest-old patients.

Charlson comorbidity index predicts anastomotic leakage in patients with resected right-sided colon cancer.

PURPOSE: Anastomotic leakage after right-sided colon cancer surgery is a serious complication that affects postoperative mortality. The Charlson comorbidity index (CCI) has been reported to be a useful predictor of postoperative complications. METHODS: A total of 593 cases of right-sided colon cancer resections performed from 2016 to 2020 were examined. The patients were divided into two groups according to the presence or absence of anastomotic leakage (AL, n = 28; no-AL, n = 565); clinicopathological and surgical characteristics were compared between the groups. RESULTS: The AL group patients had a higher comorbidity rate (96.4% vs. 66.9%, p < 0.001), higher CCI score (p < 0.001), higher blood loss (42 mL vs. 23 mL, p = 0.046), and longer hospital stay (30 days vs. 12 days, p < 0.001) than the no-AL group patients. The percentages of chronic pulmonary disease (14.3% vs. 3.9%, p = 0.029), cerebrovascular disease (14.3% vs. 1.9%, p = 0.022), connective tissue disease (39.3% vs. 3.2%, p < 0.001), leukemia (3.6% vs. 0%, p = 0.042), and moderate to severe liver disease (7.1% vs. 0%, p = 0.002) were significantly higher in the AL group. In the multivariate analysis, CCI ≥ 2 was identified as an independent predictor of postoperative anastomotic leakage (hazard ratio 4.91, 95% confidence interval 2.23-10.85, p < 0.001). CONCLUSIONS: CCI could predict anastomotic leakage after right-sided colon cancer surgery.

Evaluation of Preoperative Magnetic Resonance Cholangiopancreatography in Acute Cholecystitis to Predict Technical Difficulties in Laparoscopic Cholecystectomy.

Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging technique that provides high-quality visualization of the biliary tree, including the gallbladder. This study aimed to evaluate the useful-ness of preoperative MRCP for acute cholecystitis in predicting technical difficulties during laparoscopic chole-cystectomy (LC). A total of 168 patients who underwent LC with preoperative MRCP were enrolled in this study. Patients were divided into two groups according to preoperative MRCP findings: the visualized group (n = 126), in which the entire gallbladder could be visualized; and the non-visualized group (n = 42), in which the entire gallbladder could not be visualized. The perioperative characteristics and postoperative complica-tions of the two groups were retrospectively analyzed. Operation time was longer in the non-visualized group (median 101.5 vs. 143.5 min; p < 0.001). The non-visualized group had significantly more intraoperative blood loss than the visualized group (median 5 vs. 10 g; p = 0.05). The rate of conversion to open cholecystectomy was significantly higher in the non-visualized group (1.6 vs. 9.5%; p = 0.03). In conclusion, patients in the non- visualized group showed higher difficulty in performance of LC. Our MRCP-based classification is a simple and effective means of predicting difficulties in performing LC for acute cholecystitis.

Synchronous Total Occlusion of the Celiac Axis and Superior Mesenteric Artery: An Autopsy Case.

Acute mesenteric ischemia (AMI) is often caused by superior mesenteric artery (SMA) embolization. We report a rare case of synchronous celiac axis and SMA embolization in an elderly woman with initially mild abdominal pain. Ultimately, a second contrast-enhanced computed tomography revealed extensive necrosis from the stomach to the transverse colon together with liver ischemia due to hours of occlusion. Multiorgan failure made palliation the only option, and she died the following evening. Autopsy revealed a fragile atherosclerosis-asso-ciated thrombus. Careful examination and repeat diagnostic tests should be performed in patients with mild abdominal symptoms at risk for AMI.

Factors related to short-term outcomes and delayed systemic treatment following primary tumor resection for asymptomatic stage IV colorectal cancer.

BACKGROUND: The effectiveness of primary tumor resection (PTR) for asymptomatic stage IV colorectal cancer patients to continue prolonged and safe systemic chemotherapy has recently been re-evaluated. However, postoperative complications lead to a prolonged hospital stay and delay systemic treatment, which could result in a poor oncologic outcome. The objective of this study was to identify the risk factors for morbidity and delay of systemic chemotherapy in such patients. METHODS: Between April 2016 and March 2018, 115 consecutive colorectal cancer patients with distant metastasis who had no clinical symptoms and underwent PTR in all participating hospitals were retrospectively reviewed. The patients were divided into two groups according to the presence (CD ≥ 2, n = 23) or absence (CD < 2, n = 92) of postoperative complications. RESULTS: The proportion of combined resection of adjacent organs was significantly higher in the postoperative complication group (p = 0.014). Complications were significantly correlated with longer hospital stay (p < 0.001) and delay of first postoperative treatment (p = 0.005). Univariate and multivariate analyses showed that combined resection (odds ratio 4.593, p = 0.010) was the independent predictor for postoperative complications. Median survival time was 8.5 months. Postoperative complications were not associated with overall survival, but four patients (3.5%) could not receive systemic chemotherapy because of prolonged postoperative complications. CONCLUSIONS: Although PTR for asymptomatic stage IV CRC patients showed an acceptable prognosis, appropriate patient selection is needed to obtain its true benefit.

The C-reactive protein to albumin ratio predicts postoperative complications in oldest-old patients with colorectal cancer.

PURPOSE: The C-reactive protein to albumin ratio (CAR) is a simple and useful score for predicting the outcomes of patients with various cancers. The aim of this study was to evaluate the CAR and short-term outcomes in oldest-old patients with colorectal cancer. METHODS: A total of 126 patients aged 85 years and older with colorectal cancer who underwent resection for primary colon cancer from April 2015 to December 2018 were included. The preoperative cutoff value of the CAR for predicting postoperative complications was 0.19 on receiver operating characteristic curve analysis. Clinical characteristics and inflammation-based scores were compared between patients with a high CAR (CAR ≥ 0.19, n = 44) and a low CAR (CAR < 0.19, n = 82). RESULTS: A high preoperative CAR level (≥ 0.19) was significantly associated with stoma construction (p = 0.004), blood loss (p = 0.003), postoperative complications (p = 0.016), and systemic inflammation marker levels, including a low neutrophil to lymphocyte ratio (p = 0.006), a low platelet to lymphocyte ratio (p = 0.005), a low prognostic nutritional index (p < 0.001), and a high modified Glasgow prognostic score (p < 0.001). On univariate and multivariate analyses, only the CAR was an independent predictor of postoperative complications (HR 2.864, p = 0.029). CONCLUSIONS: A high CAR was significantly associated with postoperative complications for oldest-old patients with colorectal cancer.

Predictors of portal and splenic vein thrombosis after laparoscopic splenectomy: a retrospective analysis of a single-center experience.

PURPOSE: Laparoscopic splenectomy (LS) has become the standard operative approach for splenectomy. Portal or splenic vein thrombosis (PSVT) is a serious and common complication after LS, and lethal complications of PSVT can occur when the portal vein is completely occluded by portal vein thrombosis (PVT). We aimed to clarify the predictors of PSVT after LS and to determine which of them were also predictors of PVT. METHODS: A total of 56 consecutive patients who underwent elective LS were enrolled in this study. The patients were divided into two groups based on the presence or absence of PSVT after LS. In addition, patients with PSVT were divided into two groups: a PVT group and a non-PVT group. The preoperative and intraoperative clinical data were compared among the groups. RESULTS: Thirty (53.6%) patients developed PSVT. The splenic vein diameter was the most useful predictor for the development of PSVT, and 10 mm was an accurate splenic vein diameter cut-off value for use as a predictive factor for PSVT. In addition, the splenic vein diameter was the most useful predictor of the development of PVT from splenic vein thrombosis (SVT), and 14 mm was found to be an accurate cut-off value. CONCLUSION: PSVT is a common postoperative complication that is identified on enhanced computed tomography. The splenic vein diameter is not only a predictor of PSVT but also of the development of PVT from SVT.

E-PASS score as a useful predictor of postoperative complications and mortality after colorectal surgery in elderly patients.

PURPOSE: The aim of this study was to clarify whether a surgical-specific risk scoring system estimating the physiologic ability and surgical stress (E-PASS) score was useful for prediction of postoperative morbidity and mortality. METHODS: The E-PASS score consists of the preoperative risk score (PRS), surgical stress score (SSS), and the comprehensive risk score (CRS). Conventional scoring systems [colorectal physiologic and operative severity score for the enumeration of mortality (CR-POSSUM) and the prognostic nutritional index (PNI)] were also examined. We retrospectively compared these scores in patients with or without postoperative complications. We assessed the relationship between these scores, clinicopathological features and postoperative mortality. RESULTS: Postoperative complications developed in 78 patients (33%). American Society of Anesthesiologists score, performance status, PNI score, PRS, SSS, and CRS were significantly higher in patients with postoperative complications than in those without postoperative complications (p < 0.05). The area under the receiver operating characteristic curve (AUC) was highest for E-PASS [E-PASS (PRS, 0.74; SSS, 0.62; CRS, 0.78), PNI (0.62), CR-POSSUM (PS, 0.57; OSS, 0.52)]. Multivariate logistic analysis identified CRS ≥ 0.2 as a significant determinant of postoperative complications (p < 0.01; hazard ratio, 4.84). Overall survival was significantly better in the CRS < 0.2 group than in the CRS > 0.2 group (p < 0.01). CONCLUSIONS: The E-PASS score system was a useful predictor of postoperative complications and mortality, especially in patients with advanced age.