The effect of staple height and rectal-wall thickness on anastomotic leakage after laparoscopic low anterior resection.

BACKGROUND: The aim of this study was to evaluate the effect of staple height and rectal wall thickness on the development of an anastomotic leak after laparoscopic low anterior resection performed with the double stapling technique. METHODS: One hundred ninety-nine patients treated from 2013 to 2021 were enrolled. Patients were divided into two groups: those who developed an anastomotic leak (AL (+)) and those who did not (AL (-)). Clinicopathological factors were compared between the groups. RESULTS: Anastomotic leaks were observed in 8/199 patients (4%). A 1.5 mm linear stapler was used for 35/199 patients (17%), 1.8 mm for 89 (45%), and 2 mm for 75 (38%). In the AL (+) group (n = 8), lower staple height (1.5 mm or 1.8 mm) was used more frequently than in the AL (-) group (n = 191). Rectal wall thickness and the rectal wall thickness to staple height ratio was significantly (p < .05) greater in the AL (+) group. However, rectal wall thickness was significantly (p < .05) greater in patients who received neoadjuvant treatment and those with advanced T stage (T3,4) lesions. CONCLUSION: Linear stapler staple height and rectal wall thickness are significantly associated with the development of an anastomotic leak after laparoscopic low anterior resection. Larger staples should be selected in patients with a thicker rectal wall due to neoadjuvant treatment or adjacent advanced rectal tumors.

Metachronous common iliac lymph node metastasis after rectosigmoid colon cancer resection: A case report.

INTRODUCTION AND IMPORTANCE: Metastases to common iliac lymph nodes from cancer of the rectosigmoid are extremely rare. We report a patient with a right common iliac lymph node metastasis after rectosigmoid cancer resection. CASE PRESENTATION: The patient is a 57-year-old woman diagnosed with rectosigmoid cancer (Stage IIIc) who underwent laparoscopic resection followed by 8 courses of adjuvant chemotherapy with capecitabine. Sixteen months after resection, an intra-abdominal mass and a left lung nodule were found on computed tomography scans, which were suspected to be recurrences. Exploratory laparoscopy showed that the abdominal lesion was an enlarged common iliac lymph node, which was completely excised. No other intraabdominal recurrences were found. Subsequently, a left upper lobe lung metastasis was resected thoracoscopically. However, multiple lung metastases developed four months after the lung resection, and systemic therapy was begun. CLINICAL DISCUSSION: A lower incidence of lateral lymph node metastases from cancer in the rectosigmoid has been reported. Direct lymphatic pathways from the sigmoid colon or rectosigmoid to lateral lymph nodes have been suspected, which may be associated with the poor prognosis in this patient. CONCLUSION: A metachronous metastasis to a common iliac lymph node from primary rectosigmoid cancer is reported. Common iliac lymph node metastases from rectosigmoid cancer might have more malignant potential, and should be treated in the same manner as peri-aortic lymph node metastases.

Intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine model.

PURPOSE: The aim of this study was to evaluate both the intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine survival model. METHODS: We used two suture models using two different size staples (incomplete mucosal closure model: group G [staple height 0.75 mm], complete mucosal closure model: group B [staple height 1.5 mm]) in the porcine ileum. Five staple lines were created in each group made in the ileum for each model, and the staple sites harvested on days 0, 2, and 7. The leak pressure at the staple site was measured at each time point. RESULTS: On day 0, the leak pressure for group G (79.5 mmHg) was significantly lower than that for group B (182.3 mmHg) (p < 0.01). On days 2 and 7, there was no significant difference between groups G and B (171 mmHg and 175.5 mmHg on day 2, 175.5 mmHg and 175.5 mmHg on day 7, p > 0.05). The histological findings in both groups showed similar healing at postoperative days 2 and 7. CONCLUSION: The integrity of the mucosal staple lines was associated with the postoperative leak pressure on day 0. However, there was no association with the leak pressure at two days or more postoperatively in a porcine model.

Flow cytometry detection of cell type-specific expression of programmed death receptor ligand-1 (PD-L1) in colorectal cancer specimens.

AIM: PD-1/PD-L1 blockade therapy is now widely used for the treatment of advanced malignancies. Although PD-L1 is known to be expressed by various host cells as well as tumor cells, the role of PD-L1 on non-malignant cells and its clinical significance is unknown. We evaluated cell type-specific expression of PD-L1 in colorectal cancer (CRC) specimens using multicolor flow cytometry. METHODS: Single cell suspensions were made from 21 surgically resected CRC specimens, and immunostained with various mAbs conjugated with different fluorescent dyes. Tumor cells, stromal cells, and immune cells were identified as CD326(+), CD90(+) and CD45(+) phenotype, respectively. CD11b(+) myeloid cells, CD19(+) B cells and CD4(+) or CD8(+) T cells were also stained in different samples, and their frequencies in the total cell population and the ratio of PD-L1(+) cells to each phenotype were determined. RESULTS: PD-L1 was expressed by all the cell types. The ratio of PD-L1(+) cells to CD326(+) tumor cells was 19.1% ± 14.0%, lower than those for CD90(+) stromal cells (39.6% ± 16.0%) and CD11b(+) myeloid cells (31.9% ± 14.3%). The ratio of PD-L1(+) cells in tumor cells correlated strongly with the ratio in stromal cells, while only weakly with that in myeloid cells. Tumor cells were divided into two populations by CD326 expression levels, and the PD-L1 positive ratios were inversely correlated with the rate of CD326 highly expressing cells as well as mean fluorescein intensity of CD326 in tumor cells, while positively correlated with the frequencies of stromal cells or myeloid cells in CRC. CONCLUSION: PD-L1 is differentially expressed on various cell types in CRC. PD-L1 on tumor cells may be upregulated together with CD326 downregulation in the process of epithelial mesenchymal transition. Quantification of cell type-specific expression of PD-L1 using multicolor flow cytometry may provide useful information for the immunotherapy of solid tumors.

Solid-pseudopapillary neoplasm of the pancreas in a patient with familial adenomatous polyposis: a case report.

BACKGROUND: Familial adenomatous polyposis (FAP) is characterized by the presence of hundreds to thousands of colonic polyps, and extracolonic manifestations are likely to occur. Pancreatic tumors are rare extracolonic manifestations in patients with FAP, among which solid-pseudopapillary neoplasm (SPN) are extremely rare. We report here a patient with an SPN of the pancreas found during the follow-up of FAP. CASE PRESENTATION: A 20-year-old woman was diagnosed with FAP 3 years previously by colonoscopy which revealed less than 100 colonic polyps within the entire colon. She complained of left upper abdominal pain and a 10-cm solid and cystic pancreatic tumor was found by computed tomography scan. Solid and cystic components within the tumor were seen on abdominal magnetic resonance imaging. Simultaneous laparoscopic resection of the distal pancreas and subtotal colectomy was performed. Histopathological findings confirmed the pancreatic tumor as an SPN without malignancy. Abnormal staining of beta-catenin was observed by immunohistochemical study. Multiple polyps in the colorectum were not malignant. Molecular biological analysis from peripheral blood samples revealed a decrease in the copy number of the promoter 1A and 1B region of the APC gene, which resulted in decreased expression of the APC gene. CONCLUSIONS: A rare association of SPN with FAP is reported. The genetic background with relation to beta-catenin abnormalities is interesting to consider tumor development. So far, there are few reports of SPN in a patient with FAP. Both lesions were treated simultaneously by laparoscopic resection.

Four-directional approach to the meso-transverse attachment combined with preoperative radiological vascular simulation facilitates short-term surgical outcomes in laparoscopic transverse colon cancer surgery.

INTRODUCTION: Transverse colon resection is one of the most difficult laparoscopic procedures because of anatomic hazards such as variations in the mesenteric vascular anatomy and the complex structure of organs and surrounding membranes. METHODS: We evaluated the short-term surgical outcomes of laparoscopic transverse colon resection using a creative approach. This approach included preoperative surgical simulation using virtual surgical anatomy by CT, a four-directional approach to the mesentery, and 3-D imaging during laparoscopic surgery. RESULTS: A total of 45 consecutive patients who underwent laparoscopic resection for transverse colon cancer from June 2013 to December 2017 were enrolled in this study. All procedures were completed safely, with minor postoperative complications, including two patients with anastomotic stenosis, two with intra-abdominal phlegmon, one with delayed gastric emptying, and one with pneumonia, all treated non-operatively. There were no conversions to open resection. Operation time was 203 min (range, 125-322 min), and the estimated blood loss during surgery was 5 mL (range, 0-370 mL). The mean postoperative hospital stay was 10 days (range, 7-21 days), and no patients required readmission. CONCLUSION: Short-term surgical outcomes after laparoscopic transverse colon resection demonstrated that this creative approach was safe and feasible. The four-directional approach to the meso-transverse attachment combined with preoperative radiological simulation can facilitate laparoscopic transverse colon surgery.

Utility of preoperative 3-D simulation of laparoscopic lateral pelvic lymph node dissection for advanced rectal cancer: Surgical outcomes of 10 initial cases.

INTRODUCTION: Laparoscopic lateral pelvic lymph node dissection (LPLD) is technically challenging because of the complicated anatomy of the pelvic wall. To overcome this difficulty, we introduced preoperative 3-D simulation. The aim of the study is to investigate the usefulness of preoperative 3-D simulation for the safe conduct of laparoscopic LPLD for rectal cancer. METHODS: After undergoing colonoscopy, patients were brought to the radiology suite where multi-detector row CT was performed. Three-dimensional images were constructed at a workstation and showed branches of the iliac artery and vein, ureter, urinary bladder, and enlarged lymph nodes. All members of the surgical team participated in preoperative simulation using the 3-D images. RESULTS: A total of 10 patients with advanced lower rectal cancer and enlarged lateral pelvic lymph nodes underwent laparoscopic unilateral LPLD after total mesorectal excision, tumor-specific mesorectal excision, or total proctocolectomy. Four of the 10 patients (40%) had variations in pelvic vascular anatomy. The median operative time for unilateral LPLD was 91 min (range, 66-142 min) and gradually declined, suggesting a good learning curve. The median number of lateral pelvic lymph nodes harvested was nine (range, 3-16). The median estimated blood loss was 13 mL (range, 10-160 mL). No conversion to open surgery or intraoperative complications occurred. No patient had major postoperative complications. CONCLUSION: Preoperative 3-D simulation may be useful for the safe conduct of laparoscopic LPLD, especially for surgeons with limited prior experience.

Metachronous solitary metacarpal bone metastasis from rectal cancer.

Metachronous solitary metacarpal bone metastasis from rectal cancer has not been reported previously. Here, we describe a 54-year-old woman who underwent abdominoperineal resection for rectal cancer following neoadjuvant chemoradiotherapy. The resected specimen contained adenocarcinoma with no lymph node metastases (Stage II, T3N0M0); no adjuvant chemotherapy was administered. Fifteen months after surgery, the patient presented with pain and swelling of the right thumb. Radiography revealed metacarpal bone destruction, and fluorine-18 fluorodeoxyglucose positron emission tomography showed uptake only in the metacarpal bone. Open biopsy revealed an adenocarcinoma, and a right thumb resection was performed. Histological examination indicated features of adenocarcinoma similar to the findings of a rectal lesion, leading to a diagnosis of metachronous solitary metacarpal bone metastasis from rectal cancer. The patient remains free of disease after 6 years of follow-up. Our findings suggest that surgical resection may lead to favorable outcomes in patients with resectable solitary bone metastases.

Synchronous metastatic squamous cell carcinoma to the colon and cervical lymph nodes from a carcinoma of unknown primary site: A case report.

Metastatic squamous cell carcinoma (SCC) from an unknown primary site to the colon has not been reported previously. A 75-year-old woman presented with a mass in the left submandibular region. Biopsy revealed a Class V lesion, but the histologic type was undetermined. Surgical resection of the left submandibular gland with cervical lymph node dissection was performed. However, SCC was seen in the lymph nodes only, with no tumor in the submandibular gland. Three months after surgery, computed tomography revealed that the preoperatively diagnosed lesion in the transverse colon had grown considerably. A laparoscopic right hemicolectomy was performed. Histological examination showed features of SCC, similar to the findings in the cervical lymph nodes. We report a rare case of synchronous metastatic SCC to the colon and cervical lymph nodes from a carcinoma of unknown primary site.