Dorsal approach in laparoscopic extended left hemi-hepatectomy: A case series

RATIONALE

The utility of the dorsal approach has been reported for laparoscopic left hemi-hepatectomy.

PATIENT CONCERNS

The aim of the present study is to show the usefulness of the dorsal approach for laparoscopic extended left-hemi-hepatectomy while ensuring safe identification of hepatic veins and dissection of the dorsal tumor margin.

DIAGNOSES

Tumors requiring extended left hemi-hepatectomy.

INTERVENTIONS

After mobilization of the lateral sector and division of the Arantius plate, parenchyma above the Arantius plate is removed to expose the root of the middle hepatic vein and left hepatic vein. Each of these veins can be isolated separately either intra- or extra-hepatically. After removing the parenchyma on the cranial side of the left Glissonean pedicle continuous with the exposed hepatic veins, the left Glissonean pedicle is isolated using the Glissonean pedicle transection method. After division of the left hepatic vein and Glissonean pedicle, segment 4 (in which the main part of the tumor is commonly located) is dissected from the anterior plane of the paracaval portion of the caudate lobe by the dorsal approach, along with the hepatic hilum. Following dissection of the dorsal side of the tumor, and division of parenchyma from the anterior edge of the liver, the anterior Glissonean branches and middle hepatic vein are divided safely and the specimen is resected.

OUTCOMES

Three patients underwent laparoscopic extended left hemi-hepatectomy, with no open conversions. Operative time and blood loss were 331 (concomitant with another partial hepatectomy), 277, and 315 minutes; and 200, 100, and 100 g, respectively. The postoperative courses were uneventful.

LESSONS

The dorsal approach maximizes the advantages of laparoscopic extended left hemi-hepatectomy and can be performed safely.

Albumin-indocyanine green evaluation of future liver remnant predicts liver failure after anatomical hepatectomy for hepatocellular carcinoma: A dual-center retrospective study

Aim

The albumin-indocyanine green evaluation (ALICE) score is a useful predictor of post-hepatectomy liver failure (PHLF); however, its usefulness in combination with future liver remnant (FLR), measured by 3-D volumetry, has not been investigated. This study aimed to investigate the relationship between the ALICE of the FLR (ALICE-FLR) score and severe PHLF.

Methods

The clinical data of 215 patients who underwent anatomical hepatectomy for hepatocellular carcinoma without portal vein embolization at two institutes between January 2010 and December 2021 were analyzed retrospectively. PHLF occurrence and severity were determined according to the International Study Group of Liver Surgery's definition. Grades B and C PHLF were defined as severe PHLF. The ALICE-FLR, ALICE scores, and indocyanine green clearance of FLR (ICGK-FLR) were evaluated for severe PHLF prediction.

Results

Severe PHLF was observed in 40 patients (18.6%). The areas under the curve (AUCs) for the ALICE-FLR, ALICE scores, ICGK-FLR, and FLR were 0.76, 0.64, 0.73, and 0.69, respectively. The AUC of the ALICE-FLR score was significantly higher than that of the ALICE score. The ALICE-FLR score was identified as an independent predictor of severe PHLF (the odds ratio for every 0.01 increment in the ALICE-FLR score was 1.24; 95% confidence interval, 1.070-1.453; p = 0.004). Among patients with severe PHLF, the ALICE-FLR score was significantly higher in the grade C than in the grade B PHLF group.

Conclusion

The combination of liver function models, including indocyanine green, albumin, and FLR is considered compatible for predicting severe PHLF.

C-Reactive Protein-to-Albumin Ratio to Predict Tolerability of S-1 as an Adjuvant Chemotherapy in Pancreatic Cancer

Adjuvant chemotherapy (AC) with S-1 after radical surgery for resectable pancreatic cancer (PC) has shown a significant survival advantage over surgery alone. Consequently, ensuring that patients receive a consistent, uninterrupted S-1 regimen is of paramount importance. This study aimed to investigate whether the C-reactive protein-to-albumin ratio (CAR) could predict S-1 AC completion in PC patients without dropout due to adverse events (AEs). We retrospectively enrolled 95 patients who underwent radical pancreatectomy and S-1 AC for PC between January 2010 and December 2022. A statistical analysis was conducted to explore the correlation of predictive markers with S-1 completion, defined as continuous oral administration for 6 months. Among the 95 enrolled patients, 66 (69.5%) completed S-1, and 29 (30.5%) failed. Receiver operating characteristic curve analysis revealed 0.05 as the optimal CAR threshold to predict S-1 completion. Univariate and multivariate analyses further validated that a CAR ≥ 0.05 was independently correlated with S-1 completion (p < 0.001 and p = 0.006, respectively). Furthermore, a significant association was established between a higher CAR at initiation of oral administration and acceptable recurrence-free and overall survival (p = 0.003 and p < 0.001, respectively). CAR ≥ 0.05 serves as a predictive marker for difficulty in completing S-1 treatment as AC for PC due to AEs.

Clamp-crushing Pancreatic Transection in Minimally Invasive Distal Pancreatectomy

BACKGROUND

Minimally invasive distal pancreatectomy has become a widely accepted procedure for tumors located in the pancreatic body or tail. However, pancreatic transection by linear stapler is generally avoided for pancreatic body tumors located above the portal vein because the surgical margin width is narrowed after taking into account the cutting allowance for insertion of the stapling device. Herein, we report a parenchymal clamp-crushing procedure that provides a sufficient surgical margin in pancreatic transection.

METHODS

Two patients with suspected early pancreatic cancer underwent pancreatic transection using the clamp-crushing procedure. The planned pancreatic transection line was set just to the left of the gastroduodenal artery in both cases. Robotic and laparoscopic distal pancreatectomy were performed in 1 patient each. Patients were positioned supine with split legs. Parenchymal transection was performed with crushing by VIO 3 (ERBE Elektromedizin) operated in softCOAG Bipolar mode with Effect 2/modulation 50. After crushing, remnant tissue was cut in autoCUT Bipolar mode operated by VIO 3 with Effect 2/modulation 50, or cut after secured by clipping.

RESULTS

The surgical duration was 253 and 212 minutes, and estimated blood loss was 0 and 50 mL in the 2 patients, and both were discharged with uneventful courses. Pathologic examination confirmed a negative surgical margin in both patients.

CONCLUSION

Clamp-crushing pancreatic transection for distal pancreatectomy might be a suitable treatment option for achieving sufficient surgical margin in pancreatic body tumors located close to the portal vein.

Impact of the inferior vena cava morphology on fluid dynamics of the hepatic veins

We reported previously that a large vertical interval between the hepatic segment of the inferior vena cava (IVC) and right atrium (RA), referred to as the IVC-RA gap, was associated with more intraoperative bleeding during hemi-hepatectomy. We conducted a computational fluid dynamics (CFD) study to clarify the impact of fluid dynamics resulting from morphologic variations around the liver. The subjects were 10 patients/donors with a large IVC-RA gap and 10 patients/donors with a small IVC-RA gap. Three-dimensional reconstructions of the IVC and hepatic vessels were created from CT images for the CFD study. Median pressure in the middle hepatic vein was significantly higher in the large-gap group than in the small-gap group (P = 0.008). Differences in hepatic vein pressure caused by morphologic variation in the IVC might be one of the mechanisms of intraoperative bleeding from the hepatic veins.

The impact of cystic duct tube on the onset time of postoperative bile leakage after hepatectomy: A propensity score-matched analysis

BACKGROUND

The cystic duct tube (C-tube) was used to reduce bile leakage (BL) incidence after hepatectomy. Nevertheless, delayed BL is sometimes experienced even using C-tube. This study investigates the impact of C-tube use on the onset time of post-hepatectomy BL.

METHODS

Data from 455 consecutive patients who underwent hepatectomy without biliary reconstruction between November 2007 and July 2020 were analyzed retrospectively. A C-tube was used for intraoperative biliary injury or in consideration of BL risk. BL was divided into two groups according to the postoperative onset time: early onset and late onset. To assess the association between C-tube use and BL, propensity score matching in a 1:1 ratio was performed to match BL risk factors between the C-tube and no-C-tube groups.

RESULTS

BL occurred in 30 (6.6%) of the 455 included patients. C-tubes were used in 51 patients (11.2%) with open hepatectomy, high-risk hepatectomy, massive blood loss, long operation time, or prophylactic drain placement. After propensity score matching, BL occurred in 17 of 102 patients (16.7%). Early-onset BL occurred significantly less frequently in the C-tube group than in the no-C-tube group (3.9% vs. 15.7%, p = 0.046); however, late-onset BL was more common in the C-tube group (9.8% vs. 3.9%, p = 0.24). Six of seven patients (85.7%) with BL with C-tube use developed BL after C-tube removal.

CONCLUSION

C-tube drainage may reduce early-onset BL in cases having risk factors for BL. Conversely, since late-onset BL often occurs after C-tube removal, attention should be paid to those cases.

Diagnostic value of quantification of cell-free DNA for suspected gallbladder cancer

Background and Aim

An accurate preoperative diagnosis as the basis for deciding the most appropriate surgical procedure is essential for patients with suspected gallbladder cancer (GBC). The aim of this study was to investigate the usefulness of cell-free DNA (cfDNA) for the preoperative detection of ≥T2 invasion in patients with suspected GBC.

Methods

Twenty-four patients who underwent resection for suspected GBC were enrolled. The concentration of cfDNA obtained from blood samples preoperatively was measured and evaluated in two distributions. The first peak (less than 200 base pairs) of cfDNA distribution was defined as the shorter fragment cfDNA, considered to originate mainly from apoptosis; and the second peak (200 base pairs or more) was defined as the longer fragment cfDNA, originating mainly from necrosis.

Results

Pathological analysis identified benign disease in 12 patients and GBC in 12 patients, of whom 6 patients had ≥pT2 GBC. Carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 were significantly higher in the ≥pT2 GBC group than in the benign/

Conclusion

CfDNA might have potential use as a diagnostic factor for patients with suspected GBC.

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Key Words

• carcinoembryonic antigen
• cell‐free DNA
• gallbladder cancer
• tumor depth

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Affiliation(s)

Katsunori Sakamoto Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Kohei Ogawa Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Kei Tamura Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Masahiko Honjo Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Kyosei Sogabe Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Chihiro Ito Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Miku Iwata Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Akimasa Sakamoto Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Mikiya Shine Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Yusuke Nishi Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Mio Uraoka Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Tomoyuki Nagaoka Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Naotake Funamizu Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan
Yasutsugu Takada Department of Hepato‐Biliary‐Pancreatic and Breast SurgeryEhime University Graduate School of MedicineEhimeJapan

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Epstein-Barr Virus-Associated Latent Malignant Lymphoma With Acute Exacerbation After Living Donor Liver Transplantation: Case Report

Concomitant malignant lymphoma at the time of transplantation is usually considered a contraindication to liver transplantation (LT). We report a case of Epstein-Barr virus (EBV)-associated malignant lymphoma that was latent preoperatively and rapidly became aggravated after LT. A 69-year-old man was referred to our hospital with an exacerbation of abdominal distension due to polycystic liver. As cystic infection, ascites, and deteriorated liver reserve function occurred after hepatic artery embolization, he underwent living-donor LT with his daughter as the donor. His respiratory condition worsened, and he was moved to the intensive care unit on postoperative day 34. Histopathologic examination of the excised liver returned around the same time revealed findings suggestive of EBV-associated malignant lymphoma in lymph nodes near the gallbladder. Subsequent computed tomography scans showed apparent neoplastic lesions in the abdominal cavity and worsening pleural effusion and ascites. Numerous atypical lymphocytes were observed in the pleural effusion and ascites, and the patient was diagnosed with exacerbation of EBV-associated malignant lymphoma. He was treated unsuccessfully with rituximab and died 66 days after LT. Caution should be exercised in elderly immunocompromised transplant candidates who may have comorbid EBV-associated lymphoproliferative disease.

Early Postoperative Varicella-Zoster Virus Encephalitis After Adult ABO-Incompatible Living Donor Liver Transplantation: A Case Report

There have never been any reports of adult varicella-zoster virus (VZV) encephalitis cases. Here, we report a case of VZV encephalitis after adult ABO-incompatible living donor liver transplantation (LDLT). A 38-year-old man with decompensated liver cirrhosis caused by the hepatitis C virus was referred to our hospital as an LDLT candidate. Rituximab was administered 3 weeks before the operation, and immunosuppression agents were administered 1 week before the LDLT. Plasma exchange was performed 3 times before the LDLT. The right lobe from his mother's liver was used for the ABO-incompatible LDLT. On postoperative day (POD) 9, vascular stenting for intraabdominal bleeding from the common hepatic artery was performed by interventional radiology and was followed by re-laparotomy for abdominal drainage of the hematoma. However, there were various degrees of continued bleeding thereafter. On POD 12, due to a convulsion seizure with loss of consciousness, the patient was started on anticonvulsant therapy. On POD 15, there was an increased frequency of convulsion attacks and a prolonged loss of consciousness. A lumbar puncture was performed on POD 20 due to the appearance of shingles. The positive polymerase chain reaction of the VZV-DNA from the cerebrospinal fluid was detected, and he was diagnosed with VZV encephalitis. He rapidly regained alertness, and there were no further observed convulsion attacks after administration of a steroid pulse and acyclovir. Brain magnetic resonance imaging performed on 2 subsequent postoperative months showed findings that matched with VZV encephalitis. He was discharged as he had recovered and was ambulatory 3 months after LDLT.

Living Donor Liver Transplantation in Patients with Preformed Donor-Specific Anti-Human Leukocyte Antigen Antibodies Using Preoperative Desensitization Therapy According to Intensity of Donor-Specific Antibodies: A Single-Center Study

BACKGROUND In liver transplantation (LT), preoperative desensitization therapy is considered necessary in patients positive for donor-specific anti-human leukocyte antigen antibodies (DSAs). However, the relationship between DSA intensity and the necessary desensitization therapy is unclear. MATERIAL AND METHODS A total of 37 adult living donor (LD) LTs performed between January 2016 and March 2022 were examined. Mycophenolate mofetil (MMF) was administered preoperatively in DSA-positive cases with positive lymphocyte cross-matching who underwent LDLT. In those with strongly positive DSA (mean fluorescence intensity 10 000), rituximab was administered 2 weeks before LDLT in addition to MMF. Cross-reactive epitope group antigen (CREG)-alone-positive cases were also treated with preoperative MMF when lymphocyte cross-matching was positive. RESULTS Of the 37 patients, 9 were DSA-positive, 7 were CREG-alone-positive, and the others were double-negative. Of 9 DSA-positive cases, desensitization therapy was performed in 7, among which rituximab administration was performed in 3 strongly DSA-positive cases. Of 7 CREG-alone-positive cases, 2 were lymphocyte cross-match-positive and underwent desensitization therapy. The 1-year survival rate was 100% in both DSA- and CREG-alone-positive cases. The frequency of T-cell mediated rejection in DSA-positive, CREG-alone-positive, and double-negative cases was 22%, 43%, and 29%, respectively, with no significant difference. Antibody-mediated rejection occurred in only 1 patient, who was strongly DSA-positive and blood-group incompatible. There was also no significant difference among the 3 groups in terms of the frequency of biliary complications or 90-day mortality. CONCLUSIONS Satisfactory LDLT results were achieved in DSA- and CREG-alone-positive cases following desensitization therapy.

Morphological response and tumor shrinkage as predictive factors in metastatic colorectal cancer treated with first-line capecitabine, oxaliplatin, and bevacizumab

BACKGROUND

Morphologic response (MR) is a novel chemotherapeutic efficacy predictor of solid tumors, especially those treated with anti-vascular endothelial growth factor antibodies. Nevertheless, the importance of systemic chemotherapy MR for colorectal liver metastases (CLM) remains unclear. We aimed to evaluate the usefulness of MR as a factor associated with the therapeutic effects of chemotherapy plus bevacizumab for initially unresectable CLM cases.

METHODS

We retrospectively evaluated the associations between MR and/or Response Evaluation Criteria in Solid Tumors (RECIST), progression-free survival (PFS), and overall survival (OS) in patients who received first-line capecitabine, oxaliplatin, and bevacizumab treatment for initially unresectable CLM using multivariate analysis. Patients who showed a complete or partial response based on the RECIST, or an optimal response based on MR, were defined as "responders."

RESULTS

Ninety-two patients were examined, including 31 (33%) patients who responded optimally. PFS and OS estimates were comparable in MR responders and non-responders (13.6 vs. 11.6 months, p = 0.47; 26.6 vs. 24.6 months, p = 0.21, respectively). RECIST responders showed better PFS and OS than non-responders (14.8 vs. 8.6 months, p < 0.01; 30.7 vs. 17.8 months, p < 0.01, respectively). The median PFS and OS estimates of MR and RECIST responders were better than those of single responders or non-responders (p < 0.01). Histological type and RECIST response were independently associated with PFS and OS.

CONCLUSION

MR predicts neither PFS nor OS; nevertheless, it may be useful when combined with the RECIST. The Ethics Committee of The Cancer Institute Hospital of JFCR approved this study in 2017 (No. 2017-GA-1123): retrospectively registered.

Geriatric Nutritional Risk Index Predicts Tolerability of S-1 as Adjuvant Chemotherapy for Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Surgery plus adjuvant chemotherapy (AC) for resectable pancreatic ductal adenocarcinoma (PDAC) has been shown to prolong survival compared with surgery alone. Thus, it is of clinical importance that these patients receive a continuous dose of S-1. The aim of this study was to examine whether the geriatric nutritional risk index (GNRI) is a predictor for the completion of S-1 as AC for PDAC.

METHODS

Seventy-seven patients who were administered S-1 as AC after pancreatectomy for PDAC between January 2010 and October 2021 were retrospectively enrolled. Predictive markers were statistically analyzed for S-1 completion, which was defined as continued oral administration with relative dose intensity of >80%.

RESULTS

Patients were divided into the S-1 complete group (n = 55; 71.4%) and S-1 incomplete group (n = 22; 28.6%). There was a significant association of higher GNRI ( P = 0.013) at the onset of AC with the completion of S-1. Receiver operating characteristic curve analysis revealed 94.4 as the optimal cutoff value of GNRI for predicting the completion of S-1. Univariate and multivariate analyses confirmed that GNRI >94.4 was independently associated with the completion of S-1 ( P = 0.007).

CONCLUSIONS

High GNRI value is a predictive marker for the completion of S-1 as AC for PDAC.

Preoperative C-Reactive Protein-to-Albumin Ratio Predicts Postoperative Pancreatic Fistula following Pancreatoduodenectomy: A Single-Center, Retrospective Study

Postoperative pancreatic fistula (POPF) following pancreatoduodenectomy (PD) is a potentially lethal complication, and it is clinically important to determine its risk preoperatively. Although C-reactive protein-to-albumin ratio (CAR) is reported to be a prognostic marker for postoperative complications in several cancers, no evidence is currently available regarding the association between preoperative CAR and POPF following PD for periampullary tumors. This study examined whether preoperative CAR could predict POPF following PD. Clinical data were retrospectively retrieved from Ehime University Hospital. The optimal cut-off value for CAR was determined using receiver operating characteristic (ROC) curve analysis. This study enrolled 203 consecutive patients undergoing PD for periampullary tumors. The CAR value was significantly higher in the POPF group than in the non-POPF group (p < 0.001). According to the ROC curve analysis, the optimal cut-off value for CAR was 0.09. Patients with CAR ≥ 0.09 had higher incidence rates of POPF than their counterparts. CAR ≥ 0.09 was a risk factor for POPF in the multivariate logistic regression analysis (odds ratio 34.5, 95% confidence interval 11.75-101.38, p < 0.001). This is the first report demonstrating an association between CAR and POPF following PD. Preoperative CAR is an independent predictive marker for POPF following PD.

Association between the Preoperative C-Reactive Protein-to-Albumin Ratio and the Risk for Postoperative Pancreatic Fistula following Distal Pancreatectomy for Pancreatic Cancer

Postoperative pancreatic fistula (POPF) are major postoperative complications (POCs) following distal pancreatectomy (DP). Notably, POPF may worsen the prognosis of patients with pancreatic cancer. Previously reported risks for POCs include body mass index, pancreatic texture, and albumin levels. Moreover, the C-reactive protein-to-albumin ratio (CAR) is a valuable parameter for prognostication. On the other hand, POCs sometimes lead to a worse prognosis in several cancer types. Thus, we assumed that CAR could be a risk factor for POPFs. This study investigated whether CAR can predict POPF risk in patients with pancreatic cancer following DP. This retrospective study included 72 patients who underwent DP for pancreatic cancer at Ehime University between January 2009 and August 2022. All patients underwent preoperative CAR screening. Risk factors for POPF were analyzed. POPF were observed in 17 of 72 (23.6%) patients. POPF were significantly associated with a higher CAR (p = 0.001). The receiver operating characteristic curve analysis determined the cutoff value for CAR to be 0.05 (sensitivity: 76.5%, specificity: 88.9%, likelihood ratio: 6.88), indicating an increased POPF risk. Univariate and multivariate analysis revealed that CAR ≥ 0.05 was a statistically independent factor for POPF (p < 0.001, p = 0.013). Therefore, CAR has the potential to predict POPF following DP.

[A Case of Unresectable Hepatocellular Carcinoma Treated using Lenvatinib and Conversion Surgery]

A 57-year-old man was treated with lenvatinib for unresectable hepatocellular carcinoma(HCC). Thereafter, the tumor marker levels decreased, and the tumor became resectable. The patient underwent portal vein embolization followed by laparoscopic extended left lobectomy. The patient's postoperative course was uneventful, and the tumor marker levels remained within the normal range. No recurrence was observed 3 months after surgery. In recent years, the use of systemic chemotherapy with drugs, such as lenvatinib, followed by conversion surgery has been reported in some cases of unresectable HCC. The present case reports successful conversion surgery following lenvatinib treatment.

Geriatric nutritional risk index as a potential prognostic marker for patients with resectable pancreatic cancer: a single-center, retrospective cohort study

In pancreatic cancer, postoperative complications (POCs) are associated with disease outcomes. The geriatric nutritional risk index (GNRI) is known to predict POCs after pancreatoduodenectomy (PD) or distal pancreatectomy (DP) in patients with hepatobiliary pancreatic tumors, including pancreatic cancer. Through POC occurrence risk, we aimed to determine whether GNRI could predict prognosis in patients who underwent PD or DP for resectable pancreatic cancer. This retrospective study examined 139 patients who underwent radical pancreatectomy for resectable pancreatic cancer at Ehime University. All patients were subjected to nutritional screening using GNRI and were followed up for POC diagnosis and patient outcomes such as overall survival (OS). Patients were divided based on the GNRI value of 99 (Low group: N = 74, GNRI < 99; High group: N = 65, GNRI ≥ 99), which was determined by receiver operating characteristic curve analysis. Multivariate analysis showed that GNRI < 99 was statistically correlated with POCs after curative pancreatic resection (p = 0.02). Univariate and multivariate analyses confirmed that GNRI < 99 was significantly associated with long OS (p = 0.04). GNRI could be a potential prognostic marker for resectable pancreatic cancer after curative pancreatic resection despite being a simple and noninvasive approach.

Intraoperative selective arterial calcium injection test to confirm complete resection of a proinsulinoma

Proinsulinoma is a subtype of insulinoma that is surgically curable, but localization can be difficult as these tumors are typically too small to be visualized by imaging. We report the case of a 53-year-old woman referred to our hospital with dizziness and headache. Her blood glucose level was 46 mg/dl and Whipple’s triad was present. Although her immunoreactive insulin level during hypoglycemia was in the normal range (5.0 μU/ml), the proinsulin level was elevated (408 pmol/l). Imaging examinations showed no evidence of pancreatic tumor. A preoperative selective arterial calcium injection (SACI) test showed excessive insulin secretion in the splenic artery region, which localized the proinsulinoma to the body or tail of the pancreas, and laparoscopic spleen-preserving distal pancreatectomy was performed. Intraoperative SACI test performed after tumor removal did not show excessive insulin secretion. The intraoperative SACI test appears to be useful for localization and for confirming complete resection of proinsulinoma.

Postoperative arterial lactate levels can predict postoperative pancreatic fistula following pancreaticoduodenectomy: A single cohort retrospective study

BACKGROUND

/Objectives: Postoperative pancreatic fistula (POPF) is a serious complication after pancreaticoduodenectomy (PD). Thus, identification of the risk factors for POPF is urgently needed. In this study, we aimed to identify whether arterial lactate (LCT) levels following PD might be a marker of the potential risk of POPF.

METHODS

Between September 2009 and December 2020, 151 patients who underwent elective PD were retrospectively enrolled. Patient characteristics, perioperative clinicopathological variables, postoperative blood biochemistry data were analyzed in univariable and multivariable analyses. Pancreatic fistula of Grade B and C was considered as POPF.

RESULTS

Patients were divided into the POPF group (n = 33, 21.9%) and non-POPF group (n = 118, 78.1%). Higher body mass index (p = 0.017), increased estimated blood loss (p = 0.047), soft textured pancreas (p = 0.007), smaller main pancreatic duct (p = 0.016), higher LCT levels (p < 0.001), higher aspartate aminotransferase levels (p = 0.023) and higher procalcitonin levels (p = 0.024) were significantly associated with POPF. Receiver operating characteristic curve analysis revealed that 2.1 mmol/L was the optimal cut-off value of LCT (sensitivity = 78.8%, specificity = 61.2%) for predicting POPF occurrence. Univariate and multivariate analyses confirmed that an LCT of ≥2.1 mmol/L was independently associated with the risk of POPF following PD (odds ratio = 6.78, 95% confidence interval = 2.22-20.74; p = 0.001).

CONCLUSIONS

Higher LCT is a predictive marker for POPF following PD.

Importance of reconstruction of middle hepatic vein tributaries of right-lobe grafts in living donor liver transplantation: demonstration of the reconstruction technique

PURPOSE

The aim of the present study on living donor liver transplantation (LDLT) using a right-lobe graft without the middle hepatic vein (MHV) was to investigate the clinical impact of MHV tributary reconstruction using our criteria and techniques.

METHODS

The medical records of 40 patients who underwent adult LDLT using a right-lobe graft without the MHV between April 2008 and December 2020 were retrospectively reviewed. In this cohort, the criterion for MHV tributary reconstruction was estimated drainage volume of each MHV tributary greater than 100 mL. The drainage vein of segment 8 (V8) was reconstructed as the common orifice of the right hepatic vein and V8 using a venous patch graft, and that of segment 5 was reconstructed using artificial vascular grafts. The outcomes were compared between the groups with and without MHV tributary reconstruction. Factors associated with postoperative massive ascites were also investigated.

RESULTS

Twenty patients underwent MHV tributary reconstruction. There were no significant differences in the amount of postoperative ascites, Clavien-Dindo classification ≥ III postoperative complications, and 90-day in-hospital mortality between the groups (P = 0.678, P = 1.000, and P = 0.244, respectively). On multivariate analyses, a low-estimated functional graft-to-recipient weight ratio, which was calculated using estimated graft volume minus the territory of MHV tributaries that was not reconstructed, was identified as an independent predictor of postoperative massive ascites (odds ratio, 40.479; 95% confidence interval, 3.823-428.622).

CONCLUSION

The present study suggests that selective MHV tributary reconstruction might be useful for achieving successful graft function.

Laparoscopic clamp-crushing enucleation with a pancreatic duct stent for tumors located close to the main pancreatic duct

The perioperative management and technical details of laparoscopic clamp-crushing enucleation for low-malignant-potential pancreatic neuroendocrine neoplasms (PNENs) located close to the main pancreatic duct (MPD) in the body/tail of the pancreas using a perioperative MPD stent are reported. The procedure was performed in two patients with PNEN (13 and 10 mm in diameter) in the body/tail of the pancreas. A naso-pancreatic stent (NPS) was placed preoperatively in both patients. Resection was performed using Maryland-type bipolar forceps. The surgical duration was 139 and 55 min, and the estimated blood loss was 5 and 0 mL, respectively. One patient was discharged uneventfully on postoperative day (POD) 12. The other patient developed a grade B pancreatic fistula, but was discharged on POD 22. Laparoscopic clamp-crushing enucleation with an NPS might be a viable treatment option for tumors located close to the MPD.

Laparoscopic remnant cholecystectomy for calculi in the remnant gallbladder following subtotal-cholecystectomy: a report of two cases

Two cases of laparoscopic remnant cholecystectomy using near-infrared fluorescence cholangiography (NIFC) for remnant gallbladder calculi following subtotal-cholecystectomy are reported. Case 1: a 36-year-old woman was referred to our hospital with acute abdomen. Computed tomography showed remnant gallbladder calculi, with detected no other findings as the cause of the abdominal pain. For intraoperative exploration of the biliary anatomy, 0.25 mg/kg of indocyanine green (ICG) was administered intravenously the day before the operation. NIFC clearly showed the common bile duct and enabled safe laparoscopic remnant cholecystectomy. She was free from symptoms after the operation. Case 2: a 40-year-old woman was referred to our hospital with epigastralgia due to remnant gallbladder calculi after open cholecystectomy. ICG was administered intravenously the day before the operation. Severe adhesions were observed in the upper abdominal cavity and there was tight adherence of the duodenum to the remnant gallbladder. NIFC showed a clear margin that appeared to be the margin between the duodenum and remnant gallbladder. However, dissection of the margin observed by NIFC caused perforation of the duodenum. The clear margin seen with NIFC was likely due to visualization of the gallbladder through the duodenum. Although NIFC is a useful modality for confirming the intraoperative biliary anatomy, it is important not to rely too heavily on NIFC alone, which may lead to misinterpretation of the anatomy.

Rare Portal Venous Anomaly in a Living Liver Donor: A Case Report

Knowledge of the anatomy of the portal system is essential for safe liver resection. We report a very rare anatomic anomaly of the portal system in a living liver donor. A 24-year-old female living liver donor was found to have anomalies of the portal system on preoperative contrast-enhanced computed tomography. The ventral branch of the right anterior segment arose from the transverse portion of the left portal vein. The gallbladder and round ligament were positioned normally. Intraoperative cholangiography for evaluation of biliary anatomy revealed very low confluence of the right and left hepatic ducts. All the bile ducts from the right lobe merged into the right hepatic duct. A right lobe graft was performed, including the ventral area of the right anterior segment. The portal branch of the ventral area of the right anterior segment could be transected extrahepatically. In the recipient operation, each of the right main portal branches, including the right posterior segment branch and the dorsal branch of the right anterior segment, and the ventral branch of the right anterior segment, were anastomosed to the right and left branches of the portal vein, respectively, of the recipient. The transected right hepatic duct of the graft was anastomosed with the recipient's common hepatic duct. Sixteen years after the liver transplant, the recipient continues to do well and has good portal flow.

Risk factors for anastomotic leakage after laparoscopic low anterior resection: A single-center retrospective study

INTRODUCTION

Anastomotic leakage (AL) is a serious complication affecting short-term and long-term outcomes in rectal cancer surgery. While laparoscopic low anterior resection is a widespread procedure, the risk factors for AL are not well established. This study aimed to evaluate risk factors for AL after laparoscopic low anterior resection with double stapling technique (DST) anastomosis.

METHODS

We performed a retrospective cohort study of laparoscopic low anterior resection with DST anastomosis for rectal cancer between January 2010 and February 2019. Finally, a total of 1197 patients were eligible for the study. Twenty-five variables were collected for univariate and multivariate analyses.

RESULTS

AL occurred in 49 patients (4.1%). In multivariate analysis, blood loss (≥70 mL) and no defunctioning stoma were independent risk factors (odds ratio [OR] 2.23; 95% confidence interval [CI] 1.08-4.34; P = .030 and OR 3.15; 95% CI 1.66-6.37; P = .0003, respectively). In addition, risk factors for AL were analyzed in 601 patients without defunctioning stoma. As a result, AL occurred in 36 patients (6.0%) and multivariate analysis demonstrated that blood loss (≥70 mL) and anastomotic level from anal verge (<5 cm) were independent risk factors (OR 3.11; 95% CI 1.24-7.44; P = .016 and OR 2.33; 95% CI 1.14-4.69; P = .020, respectively).

CONCLUSION

Laparoscopic low anterior resection is feasible and safe with a low AL rate. Important factors associated with AL were blood loss and defunctioning stoma. Without defunctioning stoma, blood loss and distal anastomosis are also important factors.

Laparoscopic partial liver resection for hepatocellular carcinoma arising from Fontan-associated liver disease: a case report

Background

The Fontan procedure (FP) is a palliative surgery for functional single ventricle. The Fontan circulation maintains pulmonary circulation by a high central venous pressure, leading to chronic congestive liver. The number of patients diagnosed with hepatocellular carcinoma (HCC) arising from liver fibrosis and cirrhosis after FP is increasing. Several reports have described surgical treatment for HCC after FP, but few have described laparoscopic surgery.

Case presentation

The patient was a 31-year-old man who had undergone the FP for single right ventricle at 3 years. Several liver masses were detected at 30 years. A liver mass in segment 3 showed increasing size concomitant with increasing alpha-fetoprotein concentration, and a solitary HCC 15 mm in diameter was diagnosed. The tumor was located on the liver surface, abutting the origin of the left hepatic vein. Laparoscopic partial liver resection was performed. The postoperative course was uneventful and the patient was discharged on postoperative day 3. The patient remained disease-free on follow-up after 7 months.

Conclusions

Although we had some concerns, such as difficulty managing general anesthesia and easy venous bleeding due to high central venous pressure, laparoscopic partial liver resection was performed with safe exposure of the left hepatic vein.

Outcomes of Surgical Treatment for Patients with Anorectal Malignant Melanoma; Results of Nine Cases in a Single Institution

Anorectal melanoma (AM) is a rare and aggressive malignancy. Two main types of surgical approach for AM are abdominoperineal resection (APR) and wide local excision (WLE). Nine patients with AM underwent surgical treatment between July 2005 and October 2017 at our institution. Two of the patients were diagnosed with localized stage, four with regional stage, and three with distant stage. Laparoscopic APR was performed in six patients with localized and regional stages, whereas palliative APR and/or WLE were performed in those with distant metastasis. Both patients with localized stage lived without relapse for 6.8 years after surgery. One of the patients with regional stage had no relapse during 3.6 years of follow-up. The other three patients had recurrence and died between 6 and 32 months after surgery. The median overall survival (OS) of the cohort was 14.8 months, and the 5- and 10-year OS were 33.3% and 16.7%, respectively. The tumor at the regional stage could be removed through WLE, but preoperative diagnosis of lymph node metastasis is difficult in patients with AM. Further development of the diagnostic method is expected, and future tasks will be to establish the selection criteria to determine which surgical approach is optimal for this devastating disease.

Postoperative elevation of C-reactive protein levels and high drain fluid amylase output are strong predictors of pancreatic fistulas after distal pancreatectomy

BACKGROUND

The aim of the present study was to identify the predictors of postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP).

METHODS

The records of 97 consecutive patients who underwent DP at Ehime University Hospital between June 2009 and August 2020 were retrospectively reviewed. Patient characteristics, preoperative blood biochemistry data, operative findings, and postoperative findings until postoperative day (POD) 3 were investigated as potential predictors of clinically relevant POPF (CR-POPF). The product of the drain fluid amylase (DFA) value (U/L) and the drainage amount (mL/day) was defined as DFA output (U/day).

RESULTS

Of 97 patients who underwent DP, 23 (23.7%) developed CR-POPF. On multivariate analyses, high C-reactive protein (CRP) levels on POD 3 (>14.0 mg/dL) and high DFA output on POD 3 (>34 U/day) were found to be independent predictors of CR-POPF (odds ratios, 7.580 and 4.751, respectively; 95% confidence intervals, 2.052-27.995 and 1.487-15.175, respectively). Furthermore, the CRP value was helpful for predicting delayed CR-POPF in patients without POPF on POD3, and DFA output was useful for predicting the development of CR-POPF in patients diagnosed with POPF on POD3.

CONCLUSION

Postoperative CRP values and DFA output may facilitate appropriate postoperative management after DP.

Usefulness of a Balloon Catheter for Intraoperative Cholangiography During Living Donor Hepatectomy: A Product Investigation

Background

Intraoperative cholangiography (IOC) during living donor liver procurement for liver transplantation is an essential procedure to avoid biliary complications in the donor and to assess the details of the biliary anatomy of the graft liver for the recipient. There are limitations to IOC using conventional methods, including that the contrast medium often passes immediately to the duodenum, making continuous enhancement of the peripheral biliary tree difficult. The usefulness of a thin balloon catheter with side holes located proximal to the balloon for IOC was evaluated.

Material/Methods

A pediatric angiography balloon catheter was used for IOC.

Results

The device was used in 2 living donors, and high-quality continuous images were easily achieved. There were no perioperative biliary complications in either donor.

Conclusions

A thin balloon catheter with side holes located proximal to the balloon catheter is useful in operations for both the donor and recipient because it allows more accurate division of the bile duct because of the clear IOC images.

Prognostic nutritional index and postoperative outcomes in patients with colon cancer after laparoscopic surgery

PURPOSE

The prognostic nutritional index (PNI) is calculated using the serum albumin and peripheral lymphocyte counts. We sought to assess the correlation between the preoperative PNI and postoperative outcomes in patients with colon cancer treated with laparoscopic surgery.

METHODS

We included 896 colon cancer patients who underwent curative laparoscopic colectomy between January 2013 and March 2016. To identify any predictors of the postoperative outcomes, we compared the clinical characteristics and immunonutritional parameters, including the PNI, between patients classified as the Clavien-Dindo grade 2 or higher (n = 99) with those classified as grade 0 or 1 (n = 797).

RESULTS

A longer surgical time and a preoperative low PNI (< 49.8) (odds ratio; 1.913, p = 0.002) were independent predictors of postoperative complications according to a multivariate analysis. A preoperative low PNI was significantly associated with an older age, a lower performance status, a lower BMI, higher CEA levels, an advanced T status, lymph node metastasis, a longer operative time, a higher blood loss, a larger tumor size, treatment with a combined resection, a longer time to bowel recovery, a longer postoperative hospital stay, and a poor overall survival.

CONCLUSIONS

A preoperative low PNI was found to be significantly associated with the incidence of postoperative complications, an advanced tumor status, and a poor prognosis. Further research is needed to understand how to best clinically utilize this promising parameter.

0594 Can a Deep Convolutional Neural Network Extract Diagnostic Information on Obstructive Sleep Apnea from Images?

Introduction

Lateral cephalometric radiography is a simple way to provide craniofacial soft/hard tissue profiles specific for patients with obstructive sleep apnea (OSA) and may thus offer diagnostic information on the disease. We hypothesized that a machine learning technology, a deep convolutional neural network (DCNN), could make it possible to detect OSA based solely on lateral cephalometric radiographs without the need for either large amounts of subjective/laboratory data or skilled analyses.

Methods

In this diagnostic study, a DCNN was developed (n=1,258) and tested (n=131) using data from 1,389 lateral cephalometric radiographs obtained from individuals diagnosed with severe OSA (n=867; apnea hypopnea index &gt;30/hour) or non-OSA (n=522; apnea hypopnea index &lt; 5) at a single center for sleep disorders from March, 2006 to February, 2017. Three kinds of data sets were prepared by changing the area of interest using a single image; original image without any modification (Full Image), image containing a facial profile, upper airway, craniofacial soft/hard tissues, and image containing part of the occipital region (upper left corner of the image; Head Only). A radiologist and an orthodontist also performed a manual cephalometric analysis of the Full Image for comparison. Observers were blinded to the patient groupings. Data analysis was performed from April, 2018 to August, 2019. When the predictive score obtained from the DCNN analysis exceeded the threshold (0.50), the patient was judged to have OSA. The primary outcome was diagnostic accuracy in terms of area under the receiver-operating characteristic curve.

Results

The sensitivity/specificity was 0.87/0.82 for Full Image, 0.88/0.75 for Main Region, 0.71/0.63 for Head Only, and 0.54/0.80 for the manual analysis. The area under the curve was the highest for Main Region (0.92): 0.89 for Full Image, 0.70 for Head Only, and 0.75 for the manual analysis.

Conclusion

A DCNN identified individuals with OSA with high accuracy. This is a useful approach that does not require any laborious analyses in a primary care setting or in remote areas where an initial specialized OSA diagnosis is not feasible.

Support

This study was supported in part by the Japan Society for the Promotion of Science (grant numbers 17K11793, 19K10236).

Laparoscopic-endoscopic cooperative surgery for ileal lipoma: A case report

This is the first report of laparoscopic-endoscopic cooperative surgery (LECS) for an ileal tumor. A 50-year-old man was admitted to our hospital with a positive fecal occult blood test. Colonoscopy detected a submucosal tumor with intussusception located in the ileum, 10 cm oral from the Bauhin valve. On further examination, he was diagnosed with an ileal lipoma. There were no signs of malignancy. LECS was performed for the ileal tumor. After submucosal elevation by injecting saline solution, a mucosal incision was made circumferentially along the tumor. A full-thickness incision was created endoscopically and laparoscopically on the circumferential mucosal incisional line. The tumor was withdrawn intraluminally by endoscopy. The defect of the ileal wall was closed laparoscopically in an axial direction with linear staplers. Histologically, the tumor was a 25-mm ileal lipoma with negative resection margins and no malignancy.

Simultaneous laparoscopic left hemicolectomy and spleen-preserving distal pancreatectomy for descending colon cancer with pancreatic invasion

Here, we describe laparoscopic colectomy with spleen-preserving distal pancreatectomy for descending colon cancer with pancreatic tail invasion. A 69-year-old man with descending colon cancer staged as clinical state IIIC (cT4b [pancreas] N1M0) underwent definitive laparoscopic surgery that was performed in collaboration with surgeons who specialize in laparoscopic colorectal and hepatobiliary-pancreatic laparoscopy. After the left colon was mobilized, tumor infiltration of the pancreas, but not the splenic vessels, was confirmed, and the spleen was preserved. The procedures were safely completed laparoscopically, without intraoperative and postoperative complications. Laparoscopic multivisceral resection could be a treatment option for similar patients but only when performed by multidisciplinary specialists.

Clinical significance of morphologic response and tumor shrinkage as predictive factors of Capeox+bevacizumab in 1st line treatment of metastatic colorectal cancer

805

Background: Capeox + bevacizumab (BV) is one of the standard treatment for metastatic colorectal cancer (mCRC) and well known to sometimes cause morphologic response (MR). However, it is not well known the predictive value of MR in palliative chemotherapy of Capeox + BV as 1st line. The aim of this study was to investigate the clinical significance of MR and tumor shrinkage as predictive factors of Capeox+BV in 1st line treatment of mCRC. Methods: A total of 159 patients with CLM were selected from 316 mCRC patients treated with Capeox+BV as 1st line chemotherapy from February 2006 to August 2016. Among these patients, 92 patients were enrolled in the this study, who satisfied following criteria; (1) tumor responce was assesed by enhanced computed tomography (CT) images every 2-3 months, and (2) dose intensity of BV at first 4 courses were above 80%. Tumor response of RECIST1.1 and MR were evaluated by 2 radiologists. They classified them as optimal, incomplete or no morphologic response according to the morphologic criteria. Results: An optimal morphologic response (OR) was observed in 34% of all patients. The median progression-free survival (mPFS) was 9.3 months in this cohort, 13.5 months in patients with OR and 11.6 months in those with incomplete/no morphologic response. And the median overall survival (mOS) was 19.5 months, 30.3 months and 23.8 months, respectively. There were no statistical significance between OR and the other, irrespective of mPFS and mOS. On the other hand, mPFS was 14.6 months in responder as CR or PR of RECIST and 8.6 months in non responder as SD or PD (p < 0.0001). Furthermore, mOS, 31.9 months and 18.5 months, respectively (p < 0.0001). Besides in 17 patients fulfilled both responder of RECIST and OR, the mOS reached 45.4 months, which was remarkably longer compared to the other groups ( < 0.0001). Conclusions: Among mCRC patients with CLM treated with Capeox+BV as the 1st line, the response of RECIST well reflected the therapeutic effect. On the other hand, MR solely was not a predictor of therapeutic effect in this study. However, both responder of RECIST and OR may be on-treatment predictors to identify excellent prognostic group.

A compact low-temperature hydrogen ion beam apparatus for in situ physical property measurements

A new compact low-temperature hydrogen ion beam apparatus has been developed for in situ physical property measurements. Introduction of hydrogen can significantly alter the physical properties of materials. Conventional methods such as exposure to H₂ gas are limited to materials having hydrogen sorption. The present method is, in principle, applicable to any material of interest. Our setup provides a facile way to conduct both low-temperature hydrogen ion beam irradiation and in situ electrical resistivity measurements, which enables observation of novel physical properties induced by the low-temperature irradiation. The lowest temperature of 3.8 K was achieved by utilizing a newly designed rotatable radiation shield and a closed-cycle cryostat, which is advantageous for long-time low-temperature experiments for heavy hydrogen doping and in situ analysis. It was found that the resistivity of ZnO largely decreased by hydrogen ion beam irradiation at 50 K. Furthermore, the in situ measurements revealed an unforeseen irreversible thermal hysteresis for resistivity.

Prognostic impact of primary tumor location in patients with metastatic colorectal cancer (mCRC) at the salvage lines

741

Background: Recently it has been suggested that primary tumor location may have a clinical impact on the front line chemotherapies; namely, right-sided tumor benefit less from cytotoxic and targeted agents compared with left-sided tumor. Regorafenib and TAS 102 have recently emerged and the prognostic impacts of tumor location on these agents are unknown. Methods: Clinical information of patients who were administrated Regorafenib and/or TAS 102 was retrospectively collected. Patients’ demographics by tumor location were compared using Fisher’s exact test. Time to treatment failure (TTF), and overall survival (OS) by tumor location were calculated using Kaplan-Meyer Methods and compared using Log-rank test. In addition, subgroup analyses were performed to see the interactions between tumor location and covariates in each agent. All tests were performed at the two-sided .05 significance level. Results: The median TTF (mTTF) and OS (mOS) were 2.0 and 8.0 months in the regorafenib group (n = 98) and were 2.4 and 7.9 months in the TAS102 group (n = 95), respectively. In the regorafenib group, 71 patients had a left-sided tumor and 27 patients had a right-sided tumor. In the TAS102 group, 64 patients had a left-sided and 31 patients had a right-sided tumor. There was no significant difference between right and left sides in both groups with the exception that a greater number of older patients was seen in right-sided in the TAS102 group. No significant difference of TTF and OS by primary site were observed in regorafenib (HR 0.92, 95% CI 0.68-1.70, P = 0.71 for TTF, HR 1.09, 95% CI 0.68-1.81, P = 0.74 for OS) and in TAS 102 (HR 0.84, 95%CI 0.53-1.36, P = 0.48 for TTF, HR 1.26, 95% CI 0.72-2.33 P = 0.43 for OS). Significant interactions were shown between presence of liver metastasis and tumor location both in TTF and OS in regorafenib (p < 0.05). On the other hand, in TAS102, significant interactions were shown between period from 1st line chemotherapy and tumor location in TTF and between time to metastasis and tumor location in OS (p < 0.05). Conclusions: In contrast to front line chemotherapy, no clinical impact of tumor location was demonstrated at the salvage lines in mCRC.

Hyperspectroscopic imager for baby fibers

Hyperspectral imaging system for diagnosing digestive diseases was newly developed in order to obtain information on pathology beyond morphology of lesions. In order to guide light reflected from a lesion, a baby fiber, which can be inserted in a forceps channel of the electronic endoscope, was also developed. The performance of the system was evaluated by animal experiment. Obtained hyperspectral data were found to have sufficient quality endurable to practical use. Harmful phenomena to a living body were not observed within the experiment. It was considered from the animal experiment that the present system could be practically used for humans.

Modification of a melanoma discrimination index derived from hyperspectral data: a clinical trial conducted in 2 centers between March 2011 and December 2013

BACKGROUND

The morphology of pigmented skin lesions (PSLs) is predominantly a result of varying concentrations and distributions of pigmented molecules such as melanin and hemoglobin. Based on these differences and the fact that their information is contained in cutaneous spectra, a hyperspectral imager (HSI) for pigmented melanoma and a single discrimination index derived from the resultant hyperspectral data are proposed.

OBJECTIVE

To develop and evaluate a new discrimination index for melanomas, compared to the previous index.

METHODS

A HSI, which is convenient for both patients and clinicians, was newly developed and used in a clinical trial conducted in 2 centers with 80 patients with primary lesions and 17 volunteers between March 2011 and December 2013. There were 24 melanomas and 110 other PSLs. A previously proposed discrimination index was used without modifications. A new index, which emphasized the essential features of melanoma, was proposed, and its performance was examined. For each index, a threshold value was set to minimize the average value of the false positive and false negative fractions. The performances of both indices were compared.

RESULTS

The sensitivity and specificity of the old index were 75% and 97%, respectively, while those of the new index were 96% and 87%.

CONCLUSION

The new index had a higher sensitivity and adequate specificity, indicating that it is more useful than the old index.

Sesquiterpenoids from the Roots of Solanum aethiopicum

, 2001 Three new sesquiterpenoids, lubiminoic acid, epilubiminoic acid and aethione, and six known sesquiterpenoids, solavetivone, 3β-hydroxysolavetivone, 13-hydroxysolavetivone, an-hydro-β-rotunol, epilubimin and lubimin, were isolated from roots of S. aethiopicum L. Their structures were elucidated by spectroscopic data.

Size and Shape Variability in Human Molars during Odontogenesis

Under the patterning cascade model (PCM) of cusp development inspired by developmental genetic studies, it is predicted that the location and the size of later-forming cusps are more variable than those of earlier-forming ones. Here we assessed whether differences in the variability among cusps in total and each particular crown component (enamel-dentin junction [EDJ], outer enamel surface [OES], and cement-enamel junction [CEJ]) could be explained by the PCM, using human maxillary permanent first molars (UM1) and second deciduous molars (um2). Specimens were µCT-scanned, and 3D models of EDJ and OES were reconstructed. Based on these models, landmark-based 3D geometric morphometric analyses were conducted. Size variability in both tooth types was generally consistent with the above prediction, and the differences in size variation among cusps were smaller for the crown components completed in later stages of odontogenesis. With a few exceptions, however, the prediction was unsupported regarding shape variability, and UM1 and um2 showed different patterns. Our findings suggested that the pattern of size variability would be caused by temporal factors such as the order of cusp initiation and the duration from the beginning of mineralization to the completion of crown formation, whereas shape variability may be affected by both topographic and temporal factors.

Development of a new measurement system to detect selectively volatile organic compounds derived from the human body

A new concept expired gas measurement system used double cold-trap method was developed. The system could detect selectively volatile organic compound (VOC) derived from the human body. The gas chromatography (GC) profiles of healthy volunteer's expired gas collected by our system were analyzed. As a result, 60 VOCs were detected from the healthy volunteer's expired gas. We examined 14 VOCs among them further, which could be converted to the concentration from the GC profiles. The concentration of almost VOCs decreased when the subjects inspired purified air compared with the atmosphere. On the other hand, isoprene was almost the same. It was strongly suggested that these VOCs were derived from the human body because the concentration of these VOCs in the atmosphere were nearly zero. Expired gas of two sleep apnea syndrome (SAS) patients were analyzed as preliminary study. As a result of the study, the concentration of some VOCs contained in the expired gas of the SAS patients showed higher value than a healthy controls.

Flow Behavior of Sandwich Injection Molding in Sequential and Simultaneous Injection

The flow behavior of skin and core materials in co-injection molding was investigated to understand the flow patterns that could lead to core breakthrough in sequential and simultaneous injection molding. A spiral-flow mold was used and the core material was loaded with a black master batch to facilitate the monitoring of the core material. PC/ABS blend was used as the skin material and ABS was the core material. It was revealed irrespective of simultaneous injection time, sandwich injection molding display the four flow regions identified earlier i. e. primary injection region, core advance region, core expansion region and core breakthrough region. The flow length of core expansion region lengthened with increasing simultaneous injection time of skin and core material while the overall injection time decreased. It was also observed that the core became thinner and wider with increasing simultaneous injection time.

The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding

The processing conditions that exert influence on the occurrence of breakthrough during sandwich injection molding were investigated. A spiral flow mold mounted on a twin-barrel injection machine fitted with a single nozzle was used. The effect of mold cavity thickness and the effects of skin material cylinder temperature on skin material viscosity, melt strength, and drawing ratio were considered. Scanning electron microscopy was used to study the morphology of the skin material at the flow front. It was found that the flow length at core expansion region increased and breakthrough phenomenon was delayed as the thickness of the mold cavity increased. When cylinder temperature is increased, the viscosity is lowered and the flow front of the skin material extends with greater ease when pushed by the core material, thus, a greater core volume can be accommodated. As the flow front progresses, the tendency is that the skin material becomes thinner. Polishing and etching followed by SEM examination of the skin material at the flow front revealed that the skin material is oriented perpendicular to the flow direction and the extent of orientation increases with increasing cylinder temperature. This further supported the observation that the deformation ratio and drawing ratio increased with increasing cylinder temperature.

The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding

The processing variables that control the occurrence of breakthrough phenomenon in sandwich injection molding were investigated. Particular attention was paid to the conditions that would yield an optimum sandwich molded part. The effects of variation of core volume ratio that would yield optimum core shot size, injection speed and the skin/core viscosity ratio were examined. The flow morphology at the various stages of flow was also explored. The study was conducted with a bar-flow mold mounted on a twin-barrel injection machine fitted with a common nozzle. It was noted that the core material flow distance depends on the core cylinder screw metering position (core shot size). At the stage at which the core material completely penetrated through the skin material (breakthrough), four distinct regions of flow could be identified. The flow distance of the core material is controlled by the injection speed of the core material while the injection speed of the skin material is of little significance. In order to increase the flow distance of the core material, it is effective to increase the core material injection speed albeit limited by an optimum value of screw metering position. It was found that the flow distance of the core material was longer when the core material viscosity was lower than that of the skin material but breakthrough occurred much earlier so core volume is limited. Breakthrough failed to occur when the viscosity of the core material was higher than that of the skin material. It was found that optimum core volume and core distribution occurred when skin/core viscosities were intermediate. The morphology of the skin material leading to breakthrough was also analyzed.