Long-term prognostic value of non-invasive lesion-specific hemodynamic index

Background

With advancement in computational fluid dynamics (CFD) technology, novel lesion-specific hemodynamic parameters can be estimated non-invasively. However, their long-term prognostic implications have not been fully defined.

Purpose

We sought to investigate the ten-year outcomes of lesion-specific hemodynamic indices derived-from coronary CT angiography (CCTA).

Methods

A total of 145 vessels (95 patients) with stable coronary artery disease who underwent fractional flow reserve (FFR) derived by coronary computed tomographic angiography (FFRCT) and invasive FFR measurement was included from the first-in-human study of FFRCT. Study participants were enrolled from October 2009 to January 2011 and were followed up until December 2020. A total of 340 lesions with % diameter stenosis ≥30% were identified, and wall shear stress (WSS) and change FFRCT across the lesion (ΔFFRCT) were obtained using CFD techniques by an independent core laboratory. The optimal cut-off for WSS and ΔFFRCT was applied for outcome analysis. The primary endpoint was target lesion failure (TLF) including cardiovascular death, target vessel myocardial infarction, and target lesion revascularization at 10 years.

Results

The median WSS and ΔFFRCT was 183.3 [112.8; 273.9] and 0.06 [0.03; 0.13]. WSS and ΔFFRCT was mildly correlated with FFRCT (r=−0.18, P=0.001 for WSS; r=−0.36, P<0.001 for ΔFFRCT). Of 179 lesions with deferral of revascularization at the index procedure of FFR measurement, TLF occurred in 16 (8.9%) lesions. In prediction of 10-year TLF, % diameter stenosis (per-lesion) ≥50%, FFRCT ≤0.80, WSS ≥256.1 dyn/cm2, and ΔFFRCT ≥0.06 were significant predictors. However, in multivariate analyses with those predictors, % diameter stenosis (per-lesion) ≥50%, FFRCT ≤0.80 became insignificant, and lesion-specific hemodynamic indices were only predictive of 10-year TLF (adjusted hazard ratio [aHR] 2.66, 95% confidence interval [CI] 0.98–7.22, P=0.055 for WSS ≥256.1 dyn/cm2; aHR 5.88, 95% CI 1.10–33.25, P=0.045 for ΔFFRCT ≥0.06). WSS ≥256.1 dyn/cm2 and ΔFFRCT ≥0.06 had higher information gain in predicting outcomes than % diameter stenosis (per-lesion) ≥50% and FFRCT ≤0.80, and both improved predictability for 10-year TLF risk of the model with % diameter stenosis (per-lesion) ≥50% and FFRCT ≤0.80 (P=0.068 for WSS ≥256.1 dyn/cm2; P=0.011 for ΔFFRCT ≥0.06) (Figure).

Conclusions

Non-invasive lesion-specific hemodynamic indices (i.e., high WSS and high ΔFFRCT) were the robust predictors of 10-year outcomes of a target lesion with incremental predictability over anatomical severity and low FFRCT. Clinical application of non-invasive hemodynamic indices will provide better long-term risk stratification over the current prognostication scheme before an invasive procedure.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Abbott, Philips, HeartFlow

Application of robots in general surgery

Background: Application of robotic surgery in the field of general surgery has been increasing. This paper is an overview of the current uses and future perspectives of robotic surgery in four major divisions—endocrine, upper gastrointestinal, hepato-biliary-pancreatic (HBP), and colorectal surgery.Current Concepts: In endocrine surgery, cosmetic advantage is the highest priority when selecting a surgical approach for thyroidectomy. Currently, the transaxillary route is the most common approach. The introduction of the single-port system could maximize the advantages of this technique. In upper gastrointestinal surgery, the use of robots has the advantage of better retrieval of lymph nodes, less bleeding, earlier discharge, and less complications than the laparoscopic approach. However, a more prospective comparative trial is required to confirm those findings. In the HBP field, the indications of robotic surgery have expanded, starting with cholecystectomy to more challenging procedures, such as donor hepatectomy and pancreaticoduodenectomy. Meticulous dissection using robots could provide benefits to patients. In colorectal surgery, robotic surgery is an excellent technical tool for minimally invasive surgeries for rectal cancers, especially in male patients with narrow, deep pelvises. However, further studies are required to confirm the impact of robotic surgery on rectal cancers.Discussion and Conclusion: Robots are used to provide optimal surgical outcomes. Investigating new technologies and innovative surgical procedures is the highly important for a surgeon in the era of minimally invasive surgery.

Postoperative bleeding in essential thrombocytosis patients with colorectal cancer: Case report and literature review

Introduction and importance

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by increased platelet count and a high risk of bleeding or thrombotic events due to platelet dysfunction. Patients with ET are treated according to their risk of complications with cytoreductive or anti-aggregant treatment. Neither guidelines for oncologic patients nor perioperative management of patients with ET have been determined.

Case presentation

A 41-year-old female patient with ET who had alternating constipation and diarrhea was referred after a screening colonoscopy diagnosing a locally advanced rectosigmoid junction colon adenocarcinoma with liver metastases. Systemic preoperative chemotherapy was indicated. The patient underwent laparoscopic low anterior resection plus volume-preserving right lobectomy of the liver. Postoperative bleeding of the internal iliac artery (IIA) associated with hematoma at the lower pelvic cavity was diagnosed and treated by interventional radiology; the patient was discharged without other complications 16 days after surgery.

Clinical discussion

ET has been related to the development of hematologic complications or second non-hematologic malignancies. A systematic review was conducted to seek guidance for the management of such patients in the perioperative period. Special perioperative care must be taken, and complications management should avoid further hemorrhages or cloth formation.

Conclusion

Under oncologic and hematological guidance, minimally invasive surgery and non-invasive management of complications are advised in the lack of published perioperative management guidelines of ET patients with colorectal cancer.

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Essential thrombocythemia (ET) is a rare clonal myeloproliferative disorder.

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ET can manifest as hemorrhage, thrombosis, and functional microvascular symptoms.

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Cytoreductive treatment and anti-aggregants are indicated in ET with a high risk of complications.

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Colorectal cancer, with its surgical and oncologic treatment, may increase the risk of adverse vascular events.

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Perioperative management of patients with ET has not been determined.

Outcomes of robotic partial excision of the levator ani muscle for locally advanced low rectal cancer invading the ipsilateral pelvic floor at the anorectal ring level

PURPOSE

The purpose of this study is to evaluate partial excision of the levator ani muscle (PELM) enables preservation of anal sphincter function although levator ani muscle (LAM) was invaded.

METHODS

Functional outcomes and oncologic outcomes of 23 consecutive patients who underwent robotic PELM for low rectal cancer at the anorectal ring level invading or abutting the ipsilateral LAM are analysed.

RESULTS

Secured resection margins were achieved, especially for the circumferential resection margin. During a median follow-up of 44 months, the 3-year local recurrence rate was 14.4%. Among patients who underwent diverting ileostomy closure, mean Memorial Sloan Kettering Cancer Center Bowel Function Instrument and Wexner scores were 68.3 ± 11.9 and 10.7 ± 5.3, respectively, at 1 year after closure.

CONCLUSION

PELM is a sphincter-preserving alternative to abdominoperineal resection (APR) or extralevator APR for low rectal cancer invading the ipsilateral LAM at the level of the anorectal ring.

Association of perioperative serum carcinoembryonic antigen level and recurrence in low-risk stage IIA colon cancer

Background

The purpose is to investigate prognosis according to serum CEA levels before and after surgery in patients with stage IIA colon cancer who do not show high-risk features.

Methods

Among the patients diagnosed with colon adenocarcinoma between April 2011 and December 2017, 462 patients were confirmed as low-risk stage IIA after surgery and enrolled. The ROC curve was used to determine cut-off values of pre- and postoperative CEA. Patients were classified into three groups using these new cut-off values.

Results

All recurrence occurred in 52 of 463 patients (11.2%). However, recurrence in group H was 15.9%, which was slightly higher than the other two groups (P = 0.04). Group L and M showed 10.5% and 12.8% overall survival, group H was higher at 21.0% (P = 0.005). Recurrence was the only risk factor in group H was significantly higher in group L (HR 2.008, 95% CI, 1.123–3.589, P = 0.019). Mortality was similar to recurrence (HR 1.975, 95% CI 1.091–3.523, P = 0.044).

Conclusion

Among patients with low-risk stage IIA colon cancer, recurrence and mortality rates were higher when perioperative serum CEA levels were above a certain level. Therefore, high CEA level should be considered a high-risk feature and adjuvant chemotherapy should be performed.

Sex differences in mapping and rhythm outcomes of a repeat atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures.

Methods

Among 3,282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5 ± 10.3 years old, 61.5% paroxysmal AF) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications, and long-term clinical recurrences after propensity score matching.

Results

The LA volume index (43.1 ± 18.6 vs. 35.8 ± 11.6 ml/m2, p < 0.001) was higher, but LA dimension (40.0 ± 6.8 vs. 41.6 ± 6.3mm, p = 0.018), LA voltage (0.94 ± 0.55 vs. 1.20 ± 0.68 mV, p = 0.002), and pericardial fat volume (89.5 ± 43.1 vs. 122.1 ± 53.9 cm3, p < 0.001) lower in women with a repeat ablation than in their male counterparts. The pulmonary vein (PV) reconnections were lower (58.7% vs. 74.9%, p = 0.001), but the proportion of extra-PV triggers (27.5% vs. 17.0%, p = 0.026) and elevated LA pulse pressures (79.7% vs. 63.7%, p = 0.019) was significantly higher in women than men. There was no significant sex difference in the procedure-related complication rate (4.6% vs. 4.2%, p = 0.791). During a 31(8∼60) month median follow-up, clinical recurrences were significantly higher in women after both the de novo procedure (log rank p = 0.039, antiarrhythmic drug [AAD]-free log rank p < 0.001) and second procedure (log rank p = 0.006, AAD-free log rank p = 0.093). A female sex (HR 1.51 [1.06-2.15], p = 0.023), non-paroxysmal AF (HR 1.78 [1.30-2.34], p < 0.010), and extra-PV triggers (HR 1.88 [1.28-2.75], p = 0.001) were independently associated with clinical recurrences after repeat procedures.

Conclusions

During the repeat AFCA procedures, PV reconnections were lower in women than men, and the existence of extra-PV triggers and an LA pressure elevation was more significant, which resulted in poor rhythm outcomes.

Upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer with synchronous liver metastases

BACKGROUND

The optimal treatment of locally advanced rectal cancer with synchronous liver metastases remains controversial. In this study, we aimed to evaluate the safety, efficacy, and oncologic outcomes of upfront chemotherapy and short-course radiotherapy with delayed surgery in patients with locally advanced rectal cancer and synchronous liver metastases.

METHODS

Forty-four patients who underwent upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer (cT3/4, <2.0 mm from the mesorectal fascia) with synchronous liver metastases between January 2010 and June 2017 were reviewed retrospectively. Primary and metastatic liver lesions were resected with curative intent. Upfront chemotherapy and short-course radiotherapy were administered. Thereafter, restaging, surgery only, or additional chemotherapy followed by surgery was performed.

RESULTS

At the time of initial diagnosis, 20 patients had <3 liver metastases; 24 patients had ≥3 liver metastases. Twenty-three patients had hemi-liver metastases; 21 patients had bilobar liver metastases. R0 resection of rectal lesions was achieved in 43 patients. Synchronous R0 resection of liver metastases was achieved in 41 patients. Postoperative complications (Clavien-Dindo Grade ≥ III) were noted in 5 patients. Grade 3/4 adverse events were observed in 26 patients. All adverse events were managed effectively with medication and supportive care. The 3-year overall survival and progression-free survival rates were 65.3% and 26.9%, respectively.

CONCLUSION

Upfront chemotherapy and short-course radiotherapy with delayed surgery appear to be safe and effective in patients with locally advanced rectal cancer and synchronous liver metastases without substantially increasing treatment induced morbidity.

Single-incision laparoscopic surgery compared to conventional laparoscopic surgery for appendiceal mucocele: a series of 116 patients

BACKGROUND

Although the safety and feasibility of conventional laparoscopic surgery (CLS) for appendiceal mucocele (AM) has been reported, studies on single-incision laparoscopic surgery (SILS) for AM have not been reported. Here, we aimed to compare the perioperative and short-term outcomes between SILS and CLS for AM and to evaluate the oncological safety of SILS.

METHODS

We retrospectively analyzed the medical records of patients, diagnosed based on computed tomography findings, who underwent laparoscopic surgery for AM between 2010 and 2018 at one institution. We excluded patients strongly suspected of having malignant lesions and those with preoperative appendiceal perforation. Patients were divided into two groups-CLS and SILS. Pathological outcomes and long-term results were investigated. The median follow-up period was 43.7 (range: 12.3-118.5) months.

RESULTS

Ultimately, 116 patients (CLS = 68, SILS = 48) were enrolled. Patient demographic characteristics did not differ between the groups. The preoperative mucocele diameter was greater in the CLS than in the SILS group (3.2 ± 2.9 cm vs. 2.3 ± 1.4 cm, P = 0.029). More extensive surgery (right hemicolectomies and ileocecectomies) was performed in the CLS than in the SILS group (P = 0.014). Intraoperative perforation developed in only one patient per group. For appendectomies and cecectomies, the CLS group exhibited a longer operation time than the SILS group (63.3 ± 24.5 min vs. 52.4 ± 17.3 min, P = 0.014); the same was noted for length of postoperative hospital stay (2.9 ± 1.8 days vs. 1.7 ± 0.6 days, P < 0.001). The most common AM etiology was low-grade appendiceal mucinous neoplasm (71/116 [61.2%] patients); none of the patients exhibited mucinous cystadenocarcinoma. Among these 71 patients, there were 8 patients with microscopic appendiceal perforation or positive resection margins. No recurrence was detected.

CONCLUSIONS

SILS for AM is feasible and safe perioperatively and in the short-term and yields favorable oncological outcomes. Despite the retrospective nature of the study, SILS may be suitable after careful selection of AM patients.

Robotic Partial Excision of Levator-Ani Muscle for Locally Advanced Low Rectal Cancer Invading Ipsilateral Pelvic Floor

Tumors at the level of the anorectal junction had required abdominoperineal resection (APR) to achieve an adequate resection margin. However, in the cases of tumor invading ipsilateral levator-ani muscle (LAM), <i>en-bloc</i> resection of the rectum with LAM including tumor would be possible. This video is to show the critical anatomic steps of this procedure. A video was produced from the robotic right partial excision of LAM (PELM) performed in a 57-year-old female patient with rectal cancer at 3 cm from the anal verge, invading the ipsilateral anorectal ring, who had received neoadjuvant chemoradiotherapy. The patient discharged at postoperative day 8 without complication. The pathology of the surgical specimen revealed ypT3N1bM0. The secure resection margin from the tumor was achieved. Robotic PELM is the sphincter-preserving technique that can be an alternative treatment option for low rectal cancer invading the ipsilateral LAM, which has been an indication for APR or extralevator APR.

Robotic Partial Excision of Levator-Ani Muscle for Locally Advanced Low Rectal Cancer Invading Ipsilateral Pelvic Floor

Tumors at the level of the anorectal junction had required abdominoperineal resection (APR) to achieve an adequate resection margin. However, in the cases of tumor invading ipsilateral levator-ani muscle (LAM), en-bloc resection of the rectum with LAM including tumor would be possible. This video is to show the critical anatomic steps of this procedure. A video was produced from the robotic right partial excision of LAM (PELM) performed in a 57-year-old female patient with rectal cancer at 3 cm from the anal verge, invading the ipsilateral anorectal ring, who had received neoadjuvant chemoradiotherapy. The patient discharged at postoperative day 8 without complication. The pathology of the surgical specimen revealed ypT3N1bM0. The secure resection margin from the tumor was achieved. Robotic PELM is the sphincter-preserving technique that can be an alternative treatment option for low rectal cancer invading the ipsilateral LAM, which has been an indication for APR or extralevator APR.

[Screening core genes and cyclin B2 as a potential diagnosis, treatment and prognostic biomarker of hepatocellular carcinoma based on bioinformatics analysis]

Objective: To screen out and explore the core gene (Hub gene) involvement and the potential role of cyclin B2 (CCNB2) in the development and prognosis of hepatocellular carcinoma (HCC) through bioinformatics methods. Methods: Four HCC-related datasets were screened, and downloaded from the GEO database. GEO2R tool was used to analyze data and identify the differentially expressed genes (DEGs). Gene Ontology (GO) and KEGG signal pathway enrichment analysis were completed using DAVID database and Cytoscape (ClueGO) plug-in, respectively. Protein-protein interaction network (PPI) of DEGs was established using the STRING database. Cytoscape software was used to visualize PPI network, key modules (cluster) construction and core genes identification. UCSC and UALCAN database were used to analyze the differential expression and survival of TCGA hepatocellular carcinoma core genes. Firebrowse, Oncomine and UALCAN databases were used to analyze the expression of core genes in multiple tumors including HCC. Real-time quantitative reverse transcription PCR (RT-qPCR) was used to detect the expression levels of candidate genes in HCC tissues and liver cancer cell lines. Results: A total of 73 DEGs were identified from the four datasets, including 15 up-regulated genes and 58 down-regulated genes. KEGG pathway enrichment analysis signal showed that DEGs were mainly enriched in tumor-related pathways. PPI network based on DEGs had screened the key modules and 10 core genes. CCNB2 and NCAPG were highly expressed in liver cancer tissues in multiple databases. CCNB2 was positively correlated with NCAPG and was considered as a key gene related to prognosis (P < 0.01). RT-qPCR results showed that CCNB2 was highly expressed in human HCC tissues and cell lines (P < 0.01). Conclusion: Successfully screened DEGs and core genes related to HCC. Among them, CCNB2 is highly expressed in HCC and is related to the survival and prognosis of patients, so it is expected to become a biomarker for the diagnosis and prognosis of HCC.

Robotics Total Mesorectal Excision Up To the Minute

Surgical techniques have evolved over the past few decades, and minimally invasive surgery has been rapidly adapted to become a preferred operative approach for treating colorectal diseases. However, many of the procedures remain a technical challenge for surgeons to perform laparoscopically, which has prompted the development of robotic platforms. Robotic surgery has been introduced as the latest advance in minimally invasive surgery. The present article provides an overview of robotic rectal surgery and describes many advances that have been made in the field over the past two decades. More specifically, the introduction of the robotic platform and its benefits, and the limitations of current robotic technology, are discussed. Although the main advantages of robotic surgery over conventional laparoscopy appear to be lower conversion rates and better surgical specimen quality, oncological and functional outcomes appear to be similar to those of other alternatives. Other potential benefits include earlier recovery of voiding and sexual function after robotic total mesorectal excision. Nevertheless, the costs and lack of haptic feedback remain the primary limitations to the widespread use of robotic technology in the field.

Does the timing of protective ileostomy closure post-low anterior resection have an impact on the outcome? A retrospective study

BACKGROUND

The optimal timing for ileostomy closure remains controversial, most of the surgeons are closing ileostomy after two to three months, although ileostomy closure considered a simple procedure, it can cause significant morbidity; this study aims to clarify any relation between the post-closure complications rate and the time from its creation to the repair.

METHOD

From January 2010 to December 2017, data retrieved for a 405 patients who had protective ileostomy closure after rectal cancer surgery, our sample has been enrolled into two arms, the first arm includes whose ileostomies closed at or before three months, and the second arm involved whose ileostomies closed after three months from the index surgery, statistical analysis was performed and compared in both arms, RESULT: The overall post-closure complications in our hospital was 23.7%, there was no significant difference between the overall complications rate for both early and late closure groups (26.8% and 22.7%) respectively (P = 0.499), The majority of the complications were intestinal obstruction, and superficial surgical site infection, there was no significant association between the interval to ileostomy reversal and the intestinal obstruction although it was higher in the late closure group, in the other hand the surgical site infection complication found to be significantly higher in the early closure group than the late closure group (15.4% Vs 5.1%) with (P = 0.002).

CONCLUSION

The duration between the creation of protective ileostomy and its reversal was not a significant independent predictor of post-closure complications rate.

Prognosis of Synchronous Colorectal Liver Metastases After Simultaneous Curative-Intent Surgery According to Primary Tumor Location and KRAS Mutational Status

BACKGROUND

Tumor location and KRAS mutational status have emerged as prognostic factors of colorectal cancer. We aimed to define the prognostic impact of primary tumor location and KRAS mutational status among synchronous colorectal liver metastases (CRLM) patients who underwent simultaneous curative-intent surgery (SCIS).

METHODS

We compared the clinicopathologic characteristics and long-term outcomes of 227 patients who underwent SCIS for synchronous CRLM, according to tumor location and KRAS mutational status. We cross-classified tumor location and KRAS mutational status and compared survival outcomes between the four resulting patient groups.

RESULTS

Forty-one patients (18.1%) had right-sided (RS) tumors and 186 (81.9%) had left-sided (LS) tumors. One-third of tumors (78/227) harbored KRAS mutations. The KRAS mutant-type (KRAS-mt) was more commonly observed among RS tumors than among LS tumors [21/41 (51.2%) vs. 57/186 (30.6%), p = 0.012]. Median follow-up time was 43.4 months. Patients with RS tumors had shorter survival times than those with LS tumors [median disease-free survival (DFS): RS, 9.9 months vs. LS, 12.1 months, p = 0.003; median overall survival (OS): RS, 49.7 months vs. LS, 88.8 months, p = 0.039]. RS tumors were a negative prognostic factor for DFS [hazard ratio (HR) 1.878, p = 0.001] and OS (HR 1.660, p = 0.060). RS KRAS-mt and LS KRAS wild-type (KRAS-wt) tumors had the worst and best oncological outcomes, respectively.

CONCLUSION

Tumor location has a prognostic impact in patients who underwent SCIS for CRLM, and RS KRAS-mt tumors yielded the worst oncological outcome. These results may allow for more tailored multimodality treatments.

Early recurrence after neoadjuvant chemoradiation therapy for locally advanced rectal cancer: Characteristics and risk factors

BACKGROUND/OBJECTIVE

Some locally advanced rectal cancer (LARC) patients treated with neoadjuvant chemoradiotherapy (CRT) prior to total mesorectal excision (TME) show early recurrence with a short disease-free interval. This is unacceptable for patients and their families, necessitating re-evaluation of the treatment process. We aimed to evaluate the risk factors and prognostic impact of early recurrence in patients who received preoperative CRT (pCRT) followed by TME for LARC.

METHODS

Of 714 patients who underwent curative resection after pCRT for LARC from January 2010 to December 2016, we included 139 who developed recurrence after resection. Patients were divided into an early recurrence group, diagnosed <12 months after primary surgery, and a late recurrence group, diagnosed ≥12 months after primary surgery.

RESULTS

Forty-nine patients experienced early recurrence and 90 experienced late recurrence. Multivariate analysis revealed that tumor regression grade (hazard ratio [HR] 2.962, 95% confidence interval [CI] 1.434-6.119, P = 0.003) and positive ypN stage (HR 2.110, 95% CI 1.144-3.892, P = 0.017) correlated with early recurrence. The 5-year overall survival rates for early and late recurrences were not significantly different (P = 0.121).

CONCLUSION

In patients with early recurrence after pCRT followed by TME, tumor regression grade and ypN stage positivity were independent predictors of the early recurrence.

Prospective study of oncologic outcomes after laparoscopic modified complete mesocolic excision for non-metastatic right colon cancer (PIONEER study): study protocol of a multicentre single-arm trial

Background

The introduction of complete mesocolic excision (CME) with central vascular ligation (CVL) for right-sided colon cancer has improved the oncologic outcomes. Recently, we have introduced a modified CME (mCME) procedure that keeps the same principles as the originally described CME but with a more tailored approach. Some retrospective studies have reported the favourable oncologic outcomes of laparoscopic mCME for right-sided colon cancer; however, no prospective multicentre study has yet been conducted.

Methods

This study is a multi-institutional, prospective, single-arm study evaluating the oncologic outcomes of laparoscopic mCME for adenocarcinoma arising from the right side of the colon. A total of 250 patients will be recruited from five tertiary referral centres in South Korea. The primary outcome of this study is 3-year disease-free survival. Secondary outcome measures include 3-year overall survival, incidence of surgical complications, completeness of mCME, and distribution of metastatic lymph nodes. The quality of laparoscopic mCME will be assessed on the basis of photographs of the surgical specimen and the operation field after the completion of lymph node dissection.

Discussion

This is a prospective multicentre study to evaluate the oncologic outcomes of laparoscopic mCME for right-sided colon cancer. To the best of our knowledge, this will be the first study to prospectively and objectively assess the quality of laparoscopic mCME. The results will provide more evidence about oncologic outcomes with respect to the quality of laparoscopic mCME in right-sided colon cancer.

Trial registration

ClinicalTrials.gov ID: NCT03992599 (June 20, 2019). The posted information will be updated as needed to reflect protocol amendments and study progress.

Late anastomotic leakage after anal sphincter saving surgery for rectal cancer: is it different from early anastomotic leakage?

PURPOSE

Although multiple studies have examined anastomotic leakage (AL) after low anterior resection (LAR), their definitions of AL varied, and few have studied late diagnosed AL after surgery. This study aimed to characterize late AL after anal sphincter saving surgery (SSS) for rectal cancer by examining clinical characteristics, risk factors, and management of patients with late AL compared with early AL.

METHODS

Data from January 2005 to December 2014 were collected from a total of 1903 consecutive patients who underwent anal sphincter saving surgery for rectal cancer and were retrospectively reviewed. Late AL was defined as AL diagnosed more than 30 days after surgery. Variables and risk factors associated with early and late diagnosed AL were analyzed by multivariate logistic regression.

RESULTS

Overall, early, and late rates of AL were 13.7%, 6.7%, and 7%, respectively. Receiving neoadjuvant chemoradiotherapy (nCRT) was a risk factor for developing late AL, but not early AL (OR, 3.032; 95% CI, 1.947-4.722; p < 0.001). Protective ileostomy did not protect against late AL. Among the 134 patients with late AL, 26 (19.4%) were classified as asymptomatic and 108 patients (80.6%) as symptomatic. The most frequent symptomatic complications related to late AL were fistula (42 cases, 39.7%), chronic sinus (33 cases, 31.1%), and stenosis (31 cases, 29.2%).

CONCLUSION

Clinical characteristics, risk factors, and management of patients with late AL after SSS were different from early AL. Close attention should be given to consider late AL as the continuation of early AL.

[Evaluation of lower facial esthetics in females with different skeletal patterns]

Objective: To evaluate lower facial profile in females in different skeletal patterns. Methods: Investigation pictures of three females with beautiful lower facial profiles from Department of Orthodontics, Henan Stomatological Hospital were collected. The skeletal patterns of these females were classified as average, low and high angle, respectively.Upper lip process point (UL) was moved backwards horizontally to reach towards the E line and go even further gradually in above pictures. The distance changed according to E line was defined as DE value. If UL was in front of E line,DE value was denoted as positive, or else negative. Collectively, we obtained 30 pictures (10 pictures in each skeletal facial type) with different DE values (-5, -4, -3, -2, -1, 0, 1, 2, 3, 4 mm), which were divided into average, low and high angle group according to the skeletal facial type. The pictures were evaluated by 144 randomly-selected adult orthodontic patients [66 males, 78 females, aged (29.4±7.7) years] who visited Department of Orthodontics, Henan Stomatological Hospital from June to September, 2019 and 138 orthodontists (including qualified orthodontists and postgraduate orthodontic students [60 males, 78 females, aged (32.2±7.1) years] who participated orthodontics conferences in Henan Stomatological Hospital in June, 2019. The acceptance rate was calculated and rate above 60% was deemed as acceptable DE range. Evaluators were also asked to choose the most esthetic profiles for the best DE value in each skeletal facial type.Data discrepancy was analyzed using Kruskal-Wallis analysis and chi-square test. Results: Most accepted DE was -2 mm among total investigators including orthodonticpatients and orthodontists. There was no difference in total acceptance rate between orthodontists and patients (P>0.05). There was statistic difference in total acceptance rate in different skeletal patterns between orthodontic patients and orthodontists (P<0.05). In total investigators, total acceptance rate was 62.1% (1 752/2 820) in average angle group, 55.4%(1 563/2 820) in high angle group and 33.5%(946/2 820) in low angle group, respectively. Acceptable DE range in three facial types was -4~2 mm (average angle), -2~2 mm (high angle) and -2~-1 mm (low angle), respectively. Conclusions: According to the evaluation of both orthodontic patients and orthodontists, the best DE was-2 mm.Total acceptance rate and acceptable DE range ranked first in average angle group, second in high angle group and third in low angle group.

The antibiofilm and collagen-stabilizing effects of proanthocyanidin as an auxiliary endodontic irrigant

AIM

To evaluate the antibiofilm effect of proanthocyanidin (PA) solution as an irrigant against Enterococcus faecalis (E. faecalis) and its influence on the mechanical properties and biodegradation resistance of demineralized root dentine.

METHODOLOGY

Enterococcus faecalis were introduced into human root dentine tubules by a serial centrifugation method and grown for 1 week. Dentine blocks infected with 1-week-old E. faecalis biofilms were treated with the following irrigants: sterile water (control), 2% chlorhexidine (CHX), 2% PA, 5% PA and 10% PA. After treatment, the live and dead bacteria proportions within E. faecalis biofilms were analysed using confocal laser scanning microscopy. To evaluate the biostability of fully demineralized dentine treated by the aforementioned irrigants, the elastic modulus and hydroxyproline release of human dentine incubated in collagenase solution were tested at baseline, after irrigant treatment and after biodegradation, respectively. Furthermore, the surface chemical bond of demineralized dentine collagen treated by various irrigants was characterized by X-ray photoelectron spectroscopy (XPS). Statistical analysis was performed using one-way anova and Tukey's post hoc multiple comparisons with the significance level at 5%.

RESULTS

The proportion of dead E. faecalis volume was significantly higher in the PA and CHX groups than that in the control group (P < 0.05). PA irrigation significantly increased the mechanical properties of demineralized dentine (P < 0.05), and the effect was enhanced with increasing PA concentration. CHX and PA groups had significantly less elasticity loss and hydroxyproline release (P < 0.05). The biomodification of dentine collagen by PA was verified by increased C-O/C-N peak percentage under C1s and C-O peak percentage under O1s narrow-scan XPS spectra.

CONCLUSIONS

Proanthocyanidin killed E. faecalis within biofilms and enhanced the biostability of the collagen matrix of demineralized root dentine. It might be used as an auxiliary endodontic irrigant with antibiofilm and collagen-stabilizing effects.

Can better surgical outcomes be obtained in the learning process of robotic rectal cancer surgery? A propensity score-matched comparison between learning phases

BACKGROUND

Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien-Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching.

RESULTS

In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st-177th cases, n = 177) and phase 2 (178th-506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs.

CONCLUSIONS

For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.

[Biological characteristics and genomic information of a bacteriophage against pan-drug resistant Klebsiella pneumoniae in a burn patient and its effects on bacterial biofilm]

Objective: To isolate a bacteriophage against pan-drug resistant Klebsiella pneumoniae in a burn patient, and to study its biological characteristics, genomic information, and effects on bacterial biofilm. Methods: (1) In 2018, pan-drug resistant Klebsiella pneumoniae UA168 (hereinafter referred to as the host bacteria) solution isolated from the blood of a burn patient in Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (hereinafter referred to as Ruijin Hospital) was used to isolate and purify the bacteriophage against pan-drug resistant Klebsiella pneumoniae from the sewage of Ruijin Hospital with sewage co-culture method, drip plate method, and double-agar plate method. The bacteriophage was named as phage KP168 and the plaque morphology was observed. (2) The phage KP168 solution was taken for cesium chloride density gradient centrifugation and dialysis, and then the morphology of phage KP168 was observed through transmission electron microscope after phosphotungstic acid negative staining. (3) The phage KP168 solution was taken to determine the lytic ability of the phage KP168 against 20 strains of pan-drug resistant Klebsiella pneumoniae isolated from the burned patients' blood in Ruijin Hospital by the drip plate method, and then the lysis rate was calculated. (4) The phage KP168 solution at a initial titer of 9.3×10(11) plaque-forming unit (PFU)/mL (400 μL per tube) and the host bacteria solution at a concentration of 1×10(9) colony-forming unit (CFU)/mL (4 mL per tube) were conventionally shaking cultured together for 4 hours at multiplicity of infection (MOI) of 10.000, 1.000, 0.100, 0.010, or 0.001, respectively (1 tube per MOI). The titer of phage KP168 was measured by the double-agar plate method (the measurement method was the same below) to select the optimal MOI. The experiment was repeated three times. (5) The host bacteria solution at a concentration of 1×10(9) CFU/mL (4 mL per tube) and the phage KP168 solution at an adjusted titer of 5×10(7) PFU/mL (400 μL per tube) were mixed at the MOI of 0.005. The plaques were counted 0 (immediately), 1, 2, 3, 4, 5, 15, and 30 minutes (1 tube at each time point) after mixing by the double-agar plate method (the counting method was the same below), and the percentage of adsorbed phages was calculated to screen for the optimal adsorption time. The experiment was repeated three times. (6) The host bacteria solution at a concentration of 1×10(9) CFU/mL (300 μL per tube) and the phage KP168 solution at a titer of 5×10(8) PFU/mL (60 μL per tube) were mixed at MOI of 0.005 and conventionally shaking cultured after standing for the optimal adsorption time. The phage KP168 titer was measured 0 (immediately), 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 minutes after culture, and a one-step growth curve was drawn. The experiment was repeated three times. (7) The phage KP168 solution at a titer of 2.5×10(10) PFU/mL was left to stand for 1 hour at 37, 40, 50, 60, or 70 ℃ (3 tubes at each time point, 1 mL per tube) for counting the plaques, and then the thermal stability curve was drawn. SM buffer at a pH values of 5.0, 6.0, 7.0, 7.4, 8.0, 9.0, or 10.0 were added to the phage KP168 solution at a titer of 3.0×10(10) PFU/mL, respectively. The mixed solution was left to stand for 1 hour at 37 ℃ (3 tubes of each pH, each tube containing 100 μL phage KP168 solution and 900 μL SM buffer), and then the plaques were counted, and an acid-base stability curve was drawn. (8) The phage KP168 solution was taken for DNA extraction and sequencing after dialysis as in experiment (2). The whole genome was annotated with Prokka to obtain the coding sequence of phage KP168. Nucleotide's BLAST function was used to proceed nucleic acid sequence alignment for finding a known phage with the highest similarity to the phage KP168 nucleic acid sequence, and Blastx function was used to translate the coding sequence into protein for its function prediction. The comparison with Antibiotic Resistance Genes Database and Virulence Factors Database was proceeded. (9) In a 96-well plate, at a MOI of 1.000, 0.100, 0.010 or 0.001 (3 wells per MOI), 20 μL phage KP168 solution at a initial titer of 5.8×10(10) PFU/mL was added to 200 μL host bacteria solution at a concentration of 1.5×10(8) CFU/mL (the same concentration below) for co-cultivation for 48 hours. After 200 μL host bacteria solution was left to stand for 48 hours, 20 μL phage KP168 solution at a titer of 1×10(6,) 1×10(7,) 1×10(8,) 1×10(9,) or 1×10(10) PFU/mL (3 wells per titer) was added respectively for action for 4 hours. In both experiments, 200 μL host bacteria solution added with 20 μL SM buffer (3 wells) acted as a negative control, and 220 μL LB culture medium (3 wells) acted as a blank control. Absorbance values were measured by a microplate reader, and inhibition/destruction rates of biofilm were calculated. The experiments were both repeated three times. Results: (1) The plaques of phage KP168 successfully isolated and purified were transparent and round, and its diameter was approximately 1.5 mm. (2) The phage KP168 has a regular polyhedron structure with a diameter of about 50 nm and without a tail. (3) The phage KP168 could lyse 13 of 20 strains of Klebsiella pneumoniae from burned patients, with a lysis rate of 65.0%. (4) When MOI was 1.000, the titer was the highest after co-culturing the phage KP168 with the host bacteria for 4 hours, which was the optimal MOI. (5) After the mixing of the phage KP168 with the host bacteria for 4 minutes, the percentage of the adsorbed phage reached the highest, which was the optimal adsorption time. (6) The one-step growth curve showed that during the lysis of the host bacteria by phage KP168, the incubation period was about 10 minutes, and the lysis period was about 40 minutes. (7) With the condition of 40 ℃ or pH 7.4, the number of plaques and the activity of phage KP168 reached the highest. (8) The genome of phage KP168 was a linear double-stranded DNA with a length of 40 114 bp. There were 48 possible coding sequences. It had the highest similarity to Klebsiella phage_vB_Kp1. The most similar known proteins corresponding to the translated proteins of coding sequences contained 23 hypothetical proteins and 25 proteins with known functions. No resistance genes or virulence factor genes were found. The GeneBank accession number was KT367885. (9) After 48 hours of co-cultivation of the phage KP168 and the host bacteria at each MOI, the inhibition rates of biofilm were similar, with an average of about 45%. After the phage KP168 with a titer of 1×10(9) PFU/mL acted on the biofilm formed by the host bacteria for 4 h, the destruction rate of biofilm was the highest, reaching an average of 42%. Conclusions: In this study, a bacteriophage against pan-drug resistant Klebsiella pneumoniae from a burn patient, phage KP168, is isolated from sewage, which belongs to the tailless phage. It has a wide host spectrum, short adsorption time, and short incubation period, with certain thermal and acid-base stability. Its genomic information is clear, and it does not contain resistance genes or virulence factor genes. It also has an inhibitory effect on the formation of bacterial biofilm and a destructive effect on the formed bacterial biofilm.

Oncologic safety and bowel function after ultralow anterior resection with or without intersphincteric resection for low lying rectal cancer: Comparative cross sectional study

BACKGROUND

Despite acceptable oncologic outcomes of sphincter preserving surgeries for low rectal cancer, bowel dysfunction occurs. This study aimed to compare the oncologic and functional bowel outcomes between ultralow anterior resection (ULAR) and intersphincteric resection (ISR) for low rectal cancer.

METHODS

One hundred sixty-four patients who underwent ULAR with or without ISR for low rectal cancer between December 2010 and May 2018 were included. The Wexner and Memorial Sloan Kettering Cancer Center (MSKCC) scores were used to evaluate the bowel function of patients. Overall survival (OS) and disease-free survival (DFS) were compared between patients.

RESULTS

The ISR group had higher incidence of major fecal incontinence than the ULAR group (75.9% vs 49.3%; P = .016). The median Wexner score decreased from 12 to 9 (P = .062) at 1-year follow-up. However, the frequency and urgency/soilage subscales of MSKCC score improved significantly in the ULAR group. ISR and follow-up interval less than 1-year significantly increased the major incontinence risk. The OS in the ULAR and ISR groups was 91.4% and 91.7%. Whereas the DFS in both groups was 79% and 79.2%, respectively.

CONCLUSION

ULAR and ISR are comparable in oncologic outcomes. Severe bowel dysfunctions and major incontinence were noted in ISR group. Careful selection of patients is mandatory.

Status of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in patients with peritoneal carcinomatosis from colorectal cancer

Peritoneal carcinomatosis (PC) was previously considered an incurable disease with a poor survival outcome. As our understanding of its biology evolved, the paradigm of the management of PC from colorectal cancer (CRC) has changed, including the combination of macroscopic disease control, cytoreductive surgery (CRS), maximal regional chemotherapy to treat residual microscopic disease, and hyperthermic intraperitoneal chemotherapy (HIPEC). As with many surgical innovations, CRS with HIPEC has evolved faster than data to support it, leaving many skeptics and critics. This review highlights the recent evidence of current practice and outcome of CRS with HIPEC. Furthermore, it also summarizes the ongoing clinical trials and potential future progress of this treatment modality.