Development of Lasing Silica Microsphere for High-Speed DNA Molecular Detection.

Laser and molecular detection techniques that have been used to overcome the limitations of fluorescent DNA labeling have presented new challenges. To address some of these challenges, we developed a DNA laser that uses a solid-state silica microsphere as a ring resonator and a site for DNA-binding reactions, as well as a platform to detect and sequence target DNA molecules. We detected target DNA using laser emission from a DNA-labeling dye and a developed solid-state silica microsphere ring resonator. The microsphere was sensitive; a single base mismatch in the DNA resulted in the absence of an optical signal. As each individual microsphere can be utilized as a parallel DNA analysis chamber, this optical digital detection scheme allows for high-throughput and rapid analysis. More importantly, the solid-state DNA laser is free from deformation, which guarantees stable lasing characteristics, and can be manipulated freely outside the solution. Thus, this promising advanced DNA laser scheme can be implemented on platforms other than optofluidic chips.

A Method to Reduce Tension Differences in Pull/Push Manipulation for a Robot in Fluorescence Emission-Guided Surgical Microscopy.

MOTIVATION: A fluorescence emission-guided microscope used to monitor the outcome of cancer removal surgery is highly effective when employing a manipulator to motorize and switch the observation direction. It is necessary to minimize the alignment of looper tension between the stands for pull/push to change the direction of the manipulator and reduce the error rate caused by tension differences. This paper presents a method to minimize the error rate of looper tension between the stands. METHODS: \The looper is inserted between the stands of the manipulator to minimize the difference in tension and make the stress on the pull and push of the looper constant. The constant stress allows the manipulator to move stably in left/right, up/down, and left/right movements, which will be effective for full-camera observation and close-up shots of the end effector. RESULTS: Reducing the tolerance for differences in the manipulator's looper tension (angle and tension) is crucial. When the input value of the looper tension angle is 50°, the output should closely match 50°. Consequently, the measured response has a tolerance of ±49.98%, resulting in an error rate of .02% (1/50th level). CONCLUSION: A method is proposed to minimize the error rate of the manipulator's looper tension in a robot-based fluorescence emission-guided microscope used to observe the status of cancer surgery. As a result, a stable manipulator with a minimal error rate can achieve a 3.986x magnification for close-up observation by switching between high and low orientations.

Design of a Miniature Observation Robot for Light Emitting Diode Irradiation and Indocyanine Green Fluorescence-emission Guided Lymph Node Monitoring in Operating Rooms.

MOTIVATION: Typical surgical microscopes used for fluorescence-based lymph node detection experience limitations such as weight and restricted adjustability of the integrated light emitting diode (LED) and camera. This restricts the capture of detailed images of specific regions within the lesion. RESEARCH GOAL: This study proposes a miniature observation robot design that offers adjustable working distance (WD) and rotational radius, along with zoom-in/zoom-out functionality. METHODS: A five-degree-of-freedom manipulator was designed, with the end effector incorporating an LED and concave lens to widen the beam width for comprehensive lesion illumination. Additionally, a long-pass filter was integrated into the camera system to enhance image resolution. EXPERIMENTAL RESULTS: Experiments were conducted using a fluorescence-expressing phantom to evaluate the performance of the robot. Results demonstrated a captured image resolution of 9600 × 3240 pixels and a zoom-in/zoom-out capacity of up to 3.68 times. CONCLUSION: The proposed robot design is cost-effective and highly adjustable, enabling suitability for rapid and accurate detection of fresh lymph nodes during surgeries. The robot's capability to detect small lesions (<1 cm), as validated by phantom tests, holds promise for the detection of minute lymph nodes.

Bevacizumab and anexelekto inhibitor, TP-0903 inhibits TGF-ß1-induced epithelial-mesenchymal transition of colon cancer cells.

The incidence of colorectal cancer (CRC) is reported to be increasing nowadays, with a large proportion of newly diagnosed CRC patients being affected by metastasis. Epithelial-mesenchymal transition (EMT) is an important event in the development of metastasis of CRC. In this study, we investigated whether the anticancer drug bevacizumab and anexelekto inhibitor, TP-0903, regulate EMT of colon cancer cells induced by transforming growth factor-beta 1 (TGF-ß1). Using quantitative real-time PCR and western blot analysis, we found that bevacizumab and TP-0903 decreased the expression levels of fibronectin, alpha-smooth muscle actin, and vimentin, whereas they restored E-cadherin expression in TGF-ß1-exposed SW480 and HCT116 cells. In addition, we elucidated that bevacizumab and TP-0903 inhibited the migration and invasion of TGF-ß1-exposed colon cancer cells using scratched wound healing, transwell migration, and Matrigel-coated invasion assays. Finally, we discovered that bevacizumab and TP-0903 inactivated the Smad 2/3 signaling pathway in TGF-ß1-exposed SW480 and HCT116 cells. Therefore, we suggest that treatment of bevacizumab and TP-0903 inhibits TGF-ß1-induced EMT of colon cancer cells through inactivation of the Smad 2/3 signaling pathway.

Clinical Impact of PD-L1 Expression for Survival in Curatively Resected Colon Cancer.

BACKGROUND: Programmed death 1 (PD-1) and its ligand PD-L1 play a key dysfunction of T lymphocytes. The purpose of this study was to assess and compare the prognostic role of tumor- TILs and its relationship with PD-L1 expression in stage II and III colon cancer. METHODS: Immunohistochemisty was used to assess the densities of CD8+, CD4+, and FOXP3+ cells, and PD-L1 expression in intraepithelial tumor site from 58 stage II and III colon cancers. These were evaluated for association with histopathologic features and overall survival. RESULTS: PD-L1-positive tumors contained a higher number of CD8+ TILs with statistical significance (p = 0.001). CD4+ TILs showed positive correlation with PD-L1 expression (p = 0.034). There were no associations between PD-L1 expression and FOXP3+ TILs. Microsatellite instability (MSI)-high status (p = 0.001; Odd ration 18.0; 95% CI = 4.3-74.8) was the strongest prognostic factor along with mucinous/poor cell differentiation, CD8 and right tumor location was associated with PD-L1 expression (p = 0.024, 0.035 and 0.033, respectively). CONCLUSION: This study demonstrated that PD-L1 expression was associated with MSI-high, increased CD8+ TILs, mucinous and poor cell differentiation, and right-sided tumor location.

Self-Regulated Smectic Emulsion with Switchable Lasing Application.

A structurally reversible smectic liquid crystal (LC) emulsion made of semifluorinated rod-type molecules in silicon oil, which is controlled by simple heating and cooling, is presented. Without adding any kind of additives, such as surfactants, polymers or emulsifiers, and without using any special tools, such as microfluidics or gas bubbling, the LC molecules spontaneously form monodisperse spherical and myelin-like structures upon cooling from the isotropic temperature. The LC emulsion can easily trap guest materials, providing a platform for repeatable and reliable switchable emulsification. For example, this interesting system enables the realization of an on-off lasing system by confining fluorescent dyes in the LC droplets.

Autologous blood, a novel agent for preoperative colonic localization: a safety and efficacy comparison study.

BACKGROUND: Preoperative localization is essential for minimally invasive colorectal surgery. However, conventional endoscopic tattooing agents such as India ink have safety issues. The availability of new endoscopic markers such as non-India-ink-based agent is limited. We assessed the efficacy and safety of preoperative endoscopic tattooing using autologous blood in colorectal surgery. METHODS: From February 2016, all patients who required localization of a target lesion before colorectal surgery underwent endoscopic tattooing using autologous blood, and the outcomes were collected prospectively. As a comparison, we retrospectively reviewed the medical records of a further 51 consecutive patients who underwent endoscopic tattooing using India ink before February 2016. A total of 102 patients who underwent endoscopic tattooing using either India ink or autologous blood were included in this study. The primary outcomes were the visibility of the tattooing in the peritoneal cavity and related adverse events. RESULTS: Endoscopic tattoos produced using India ink were visible in 49 (96.1%) patients, and tattoos created using autologous blood were visible in 47 (92.2%) patients. In the autologous blood group, the tattoo could not be identified in four patients due to excessive peritoneal fat, bleeding tendency, congenital anomaly, and suboptimal tattooing. Seven (13.7%) patients in the India ink group and three (5.9%) patients in the autologous blood group experienced endoscopic tattooing-related adverse events. CONCLUSIONS: Autologous blood is a feasible and safe tattooing agent for preoperative endoscopic localization of colorectal lesions within maximal interval of 5 days.

Risk Factors for Recurrence of Right Colonic Diverticulitis.

BACKGROUND: Right colonic diverticulitis (RCD) is more common in Asian countries than in Western countries, and the risk factors for recurrence of RCD are not fully understood. The objective of this study was to assess the risk factors for recurrence of RCD. METHODS: We analyzed 296 patients admitted for treatment of RCD in the Gachon University Gil Medical Center from December 2001 to October 2014. Gender, age, BMI, obesity, hypertension, diabetes mellitus, alcohol consumption, smoking, Hinchey classification, and hospital stay were investigated as risk factors for recurrence. RESULTS: Of the 296 patients with RCD, 31 patients recurred after conservative treatment. The median time interval between the initial episode and recurrence of diverticulitis was 10.4 months. In the univariate analysis, a high recurrence rate was observed in patients with a history of alcohol consumption, smoking, and long hospital stay. In the multivariate analysis, the recurrence rate was much higher (p < 0.001) in patients who stayed in the hospital for more than 10 days after the first attack. Smoking also elevated the recurrence rate (p = 0.011). CONCLUSION: Factors associated with recurrence of RCD may include smoking and the long hospital stay due to complexity when first diverticulitis occurs. Further prospective large-scale studies are needed to draw a definite conclusion.

Optofluidic ring resonator laser with an edible liquid laser gain medium.

We demonstrate a biocompatible optofluidic laser with an edible liquid laser gain medium, made of riboflavin dissolved in water. The proposed laser platform is based on a pulled-glass-capillary optofluidic ring resonator (OFRR) with a high Q-factor, resulting in a lasing threshold comparable to that of conventional organic dye lasers that are mostly harmful, despite the relatively low quantum yield of the riboflavin. The proposed biocompatible laser can be realized by not only a capillary OFRR, but also by an optical-fiber-based OFRR that offers improved mechanical stability, and is promising technology for application to in vivo bio-sensing.

Electro-tunable liquid crystal laser based on high-Q Fabry-Pérot microcavity.

We demonstrate an electro-tunable laser based on a plano-concave (p-c) Fabry-Pérot (FP) microcavity filled with dye-doped liquid crystal (LC) gain material. Owing to the high Q-factor of the p-c FP microcavity, the lasing threshold of the LC laser is as low as 0.58 µJ/mm2. The single-mode emission wavelength can be easily tuned by varying applied voltage, which induces the reconfiguration of LC molecules. Furthermore, this lasing platform operates at room temperature, thanks to the wide temperature range of the nematic LC. We believe that our LC laser is widely applicable to light sources of various micro total analysis systems.

Evaluation of anti-tumorigenic activity of BP3B against colon cancer with patient-derived tumor xenograft model.

BACKGROUND: KIOM-CRC#BP3B (BP3B) is a novel herbal prescription that is composed of three plant extracts. Our preliminary study identified that BP3B exhibited potent anti-proliferative activity against various types of cancer cell lines in vitro. Because the in vivo anti-tumor effect of BP3B is not evaluated before clinical trial, we want to test it using patient's samples. METHODS: To confirm the in vivo anti-cancer effect of BP3B, we used genetically characterized patient-derived colon tumor xenograft (PDTX) mouse model. Anti-cancer activity was evaluated with apoptosis, proliferation, angiogenesis and histological analysis. RESULTS: Oral administration of BP3B significantly inhibited the tumor growth in two PDTX models. Furthermore, TUNEL assay showed that BP3B induced apoptosis of tumor tissues, which was associated with degradation of PARP and Caspase 8 and activation of Caspase 3. We also observed that BP3B inhibited cancer cell proliferation by down-regulation of Cyclin D1 and induction of p27 proteins. Inhibition of angiogenesis in BP3B-treated group was observed with immunofluorescence staining using CD31 and Tie-2 antibodies. CONCLUSION: These findings indicated that BP3B has a strong growth-inhibitory activity against colon cancer in in vivo model and will be a good therapeutic candidate for treatment of refractory colon cancer.

Comparison of palonosetron, granisetron, and ramosetron for the prevention of postoperative nausea and vomiting after laparoscopic gynecologic surgery: a prospective randomized trial.

BACKGROUND: Selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are reported to have potent antiemetic effects for postoperative nausea and vomiting (PONV). The purpose of this study was to prospectively evaluate the efficacy of palonosetron, granisetron, and ramosetron for the prevention of PONV in patients undergoing laparoscopic gynecologic surgery. METHODS: In this prospective, randomized observational study, 105 healthy female patients who were undergoing laparocopic hystectomy under general anaesthesia were enrolled (clinical trial number: NCT01752374, www.clinicaltrials.gov ). Patients were divided into three groups: the palonostron (0.075 mg i.v.; n = 35), the granisetron group (3 mg i.v.; n = 35), and the ramosetron group (0.3 mg i.v.; n = 35). The treatments were given before the end of surgery. The incidence of PONV, severity of nausea/vomiting, and the use of rescue antiemetic requirements during the first 48 h after surgery were evaluated. RESULTS: The overall incidence of PONV was 33.3 % for this series. The number of complete responders at 48 h after the surgery was 21 (60.0 %) for palonosetron, 24 (68.6 %) for granisetron, and 26 (71.4 %) for ramosetron, representing no statistical difference (P = 0.086). CONCLUSIONS: There were no significant differences in the overall incidence of postoperative nausea and vomiting and complete responders for palonosetron, granisetron and ramosetron group. CLINICAL TRIAL NUMBER: NCT01752374 , www.clinicaltrials.gov .

Clinicopathological Differences between Right and Left Colorectal Cancer by Sex.

Background: Until now, studies on colorectal cancer (CRC) have focused on clinicopathological characteristics based on location without considering sex differences. However, as men and women have fundamentally different physiological characteristics, research results in the clinical field are limited. We aimed to elucidate the differences in the clinicopathological characteristics between right-sided CRC (RCC) and left-sided CRC (LCC) according to sex. Methods: We classified 1492 South Korean patients with no history of colon surgery between July 2005 and June 2015 based on tumor location and sex. For these patients, differences in the clinical characteristics according to sex were compared using univariate and multivariate analyses. Results: Of the 1269 patients, 951 (74.9%) had LCC, and 318 (25.1%) had RCC, making LCC approximately three times more common than RCC. When sex was not taken into account, patients with RCC had significantly higher rates of anemia and undifferentiated cancers than the rates in those with LCC. Even considering sex, anemia and undifferentiated cancer were more prevalent in RCC than in LCC in both men and women. In contrast, age over 65 years and abnormal white blood cell count differed between RCC and LCC only in women. Conclusions: The clinicopathologic characteristics of CRC vary according to the location and sex. Therefore, sex must be considered as a fundamental characteristic of personalized treatment.

Single-port laparoscopic appendectomy versus conventional laparoscopic appendectomy: a prospective randomized controlled study.

OBJECTIVE: To compare surgical outcomes and quality of life between single-port laparoscopic appendectomy (SPLA) and conventional laparoscopic appendectomy (CLA) in patients with acute appendicitis. BACKGROUND: A prospective randomized single center study was performed to compare the outcome of SPLA and CLA in patients with acute appendicitis. METHODS: A total of 248 patients were randomized, but because of 18 withdrawals, the outcome of 224 is analyzed, 116 in CLA and 114 in SPLA. RESULTS: There was no significant difference in the overall complication rate (P = 0.470). There were no significant differences in infectious complications between the SPLA group and the CLA group (10.2% and 12.4%, respectively). The wound complication rate between the 2 groups was not significant (5.1% and 10.6%, respectively; P = 0.207). Cosmetic satisfaction score, 36-item short-form health survey, and postoperative pain scores were not significantly different between 2 groups. CONCLUSIONS: SPLA failed to show any advantages over CLA relative to pain and cosmesis. However, SPLA is as safe as CLA (RCT number 01348464).

Clinical impact of tumor-infiltrating lymphocytes for survival in curatively resected stage IV colon cancer with isolated liver or lung metastasis.

BACKGROUND: The most reliable prognostic factor to date is tumor, node, metastasis stage. However, prognostic significance of tumor-infiltrating lymphocytes (TILs) in curatively resected stage IV colon cancer with isolated liver or lung lesion has not been clarified. The aim of this study was to assess and compare the prognostic role of TILs in curatively resected stage IV colon cancers. METHODS: Immunohistochemistry was used to assess the densities of CD8(+), CD45RO(+), and FOXP3(+) according to tumor sites (primary tumor, liver, and lung) from 79 stage IV colon cancers. These were evaluated for association with histopathologic features and patients' overall survival (OS). RESULTS: Higher density of CD45RO(+) at primary and metastatic sites was associated with better patient outcomes (P = 0.009 and 0.027, respectively). The estimated 3-year OS rates for high-density CD45RO(+) at metastatic and primary sites was 82.6 and 62.4 %, respectively, compared to 60.8 and 27.1 % in low-density CD45RO(+). In multivariate analysis, CD45RO(+) at the colon primary site (P = 0.007; relative risk 0.108; 95 % confidence interval 0.021-0.546) was the strongest prognostic factor. CONCLUSIONS: High density of CD45RO(+) TILs showed independent prognostic significance for OS. This result may help to improve the prognostication of curatively resected stage IV colon cancer.

Prognostic value of circulating cytokines for stage III colon cancer.

BACKGROUND: This study was to determine preoperative serum levels of epidermal growth factor (EGF), interleukin-6 (IL-6), and C-reactive protein (CRP) in stage III colon cancer and correlate them with disease status and prognosis. The circulating EGF in correlation with primary site epidermal growth factor receptor (EGFR) was also evaluated. METHODS: Seventy-seven patients with curatively resected stage III colon cancer were selected for analysis. Enzyme-linked immunosorbent assay was used to determine EGF and IL-6 serum levels, and serum CRP levels were measured via immunoturbidimetry. EGFR expression was observed with immunohistochemical studies. RESULTS: The median levels of EGFR, IL-6, and CRP were 189.4 pg/mL, 9.09 pg/mL, and 1.4 mg/mL, respectively. The factors related to recurrence with statistical significance included positive node status (P = 0.041), lymphovascular invasion (P = 0.001), and preoperative IL-6 level ≥9 pg/mL (P = 0.020). CRP and EGF levels were not significantly associated with disease-free survival rates (P = 0.438 and P = 0.309, respectively). Multivariate analysis using Cox's proportion model revealed that lymph node status was the single independent prognostic factor for predicting time until recurrence (odds ratio, 4.99; 95% confidence interval, 1.09-22.91; P = 0.038). CONCLUSION: IL-6 expression in stage III colon cancer patients appears to be a prognostic marker of tumor behavior. No correlations between serum EGF concentrations and tumor EGFR positivity were found in this study.

Neoadjuvant treatment of mid-to-lower rectal cancer with oxaliplatin plus 5-fluorouracil and leucovorin in combination with radiotherapy: a Korean single center phase II study.

PURPOSE: To evaluate the safety and efficacy of neoadjuvant chemoradiation with oxaliplatin and 5-fluorouracil (5-FU) in advanced mid-to-lower rectal cancer. METHODS: This was a single-arm, open-label phase II study conducted between August 2008 and August 2010. Thirty-one patients (n = 31) with clinical stage T3/T4 or lymph node positive rectal adenocarcinoma located in the middle or lower rectum without metastasis were enrolled onto the study. Data were analyzed according to the intention-to-treat principle. RESULTS: Thirty-one patients were enrolled into the study. Six patients (19.4%) experienced grade 3 diarrhea. Grade 2 nausea and vomiting occurred in 5 and 2 patients, respectively. Severe neurotoxicity was not observed. Grade 1 sensory neuropathy occurred in 10 patients (32.3%). Sphincter-saving surgery was performed in 29 patients (93.5%). The mean distance of the tumor from the anal verge was 4.9 cm. Anastomotic leakage occurred in 4 of 29 (13.8%) patients. The circumferential resection margin was involved in 2 patients (6.5%). Overall, 23 patients (77.4%) responded to treatment. The complete pathologic response (ypCR) rate was 12.9%. There was no death secondary to toxicity, and the mean follow-up time was 12.3 months. CONCLUSION: The overall toxicity of oxaliplatin and continuous 5-FU/leucovorin infusion in combination with radiation was well tolerated. Neoadjuvant chemoradiation for patients with locally advanced rectal cancer was associated with higher rates of sphincter preservation and downstaging, but did not significantly increase ypCR. The impact of this neoadjuvant chemoradiation regimen on survival will be determined by longer follow-up studies.

Direct comparison of Seprafilm® versus Adept ® versus no additive for reducing the risk of small-bowel obstruction in colorectal cancer surgery.

PURPOSE: To assess the effectiveness of using sodium hyaluronate-based bioresorbable membrane (Seprafilm(®)) versus 4 % icodextrin solution (Adept(®)) versus no additive intraoperatively and to prevent postoperative small-bowel obstruction in patients undergoing colorectal cancer (CRC) surgery. METHODS: The subjects of this retrospective study were 454 patients, who underwent CRC surgery between February 2007 and January 2010. Among the 454 enrolled patients, 114 patients received Seprafilm(®), 180 patients received Adept(®), and 160 patients received no additive, based on the year of their surgery. RESULTS: The overall incidences of small-bowel obstruction were 8.8, 4.3, and 6.9 %, for the Adept(®), Seprafilm(®), and no additive (control) groups, respectively. The cumulative incidence was significantly higher in the Adept(®) group than in the Seprafilm(®) and control groups (Adept(®) vs. Seprafilm(®), P = 0.043; Adept(®) vs. control group, P = 0.002). No significant difference was found between the Seprafilm group and the control group (P = 0.549). Adept(®) solution and Seprafilm(®) did not alter the liver and renal function, as assessed by blood chemistry. CONCLUSIONS: The use of Adept(®) significantly increased the incidence of small-bowel obstruction in patients undergoing CRC surgery.

Clinical manifestations of abdominal wall endometriosis: a single center experience.

OBJECTIVE: This study aimed to investigate the clinical manifestations and treatment outcomes of abdominal wall endometriosis (AWE). MATERIALS AND METHODS: Patients diagnosed with AWE at the Gil Medical Center from January 2002 to September 2010 were retrospectively reviewed. RESULTS: Thirty-seven women were treated for AWE during the study period. Median age was 34 (range 24-45) years, and median duration from last pelvic surgery until symptom onset was 30 (range 6-96) months. The most common initial symptom was a palpable mass (36, 97.2 %), followed by cyclic or spontaneous pain (21, 56.8 %). Preoperative diagnoses were accurate in 20 of 29 patients (68.9 %), who underwent a preoperative imaging study. The accuracy of abdominal US was 80 % (12/15). All patients underwent wide excision, and the median tumor size was 3.5 (range 1.0-10.0) cm. One patient experienced recurrence at 34 months postoperatively. CONCLUSIONS: Physicians should be aware of AWE in any woman presenting with palpable mass and/or pain at the abdominal wall, especially after pelvic surgery. Adequate preoperative estimation and wide excision might be essential for the treatment of AWE.

Can Triclosan-Coated Sutures Reduce the Incidence of Surgical Site Infections and Intra-Abdominal Infection: A Double-Blinded Randomized Controlled Trial.

Background: Surgical site infections (SSIs) are the most common nosocomial infections suffered by surgical patients. They increase medical costs and prolong hospital stay. With respect to gastrointestinal surgery, SSIs are reported to have an incidence of up to 30%, and they frequently cause morbidity. The aim of this study was to prospectively investigate whether use of triclosan-coated sutures for abdominal incision closure during colorectal surgery reduces the incidence of SSI. Patients and Methods: This was a double-blinded randomized controlled trial in a single academic surgical hospital. Patients who underwent laparoscopic or open colorectal surgery were included. Patients were pre-operatively randomly assigned to either the Vicryl® Plus (VP) or Vicryl® (Ethicon Inc., Somerville, NJ) group. The patients and medical staff were blinded. Results: The primary end point was overall SSI rate and SSI at 30 days. Over a six-year period, 811 patients who underwent colorectal surgery and provided informed consent were randomly assigned (VP group, 396 patients; Vicryl group, 415 patients). No differences in baseline demographics were observed between the groups. The overall incidence of SSI was 4.8% (39/811 patients). There were no statistically significant differences in mean length of post-operative hospital stay between the groups (VP group, 9.3 days; Vicryl group, 9.6 days; p = 0.587). Statistically significant differences in SSI rate after post-operative day 30 were observed between the groups (VP group, 1 patient [7.1%]; Vicryl group, 7 patients [28.0%]; p = 0.039). Conclusions: Although use of triclosan-coated sutures did not reduce incidence of SSI within 30 days post-operatively, it is associated with reduced SSI rate after post-operative day 30.