Natural history of branch duct intraductal papillary mucinous neoplasm with mural nodules: a Japan Pancreas Society multicenter study.

OBJECTIVE: This study aimed to elucidate the natural history of intraductal papillary mucinous neoplasm (IPMN) of the pancreas with mural nodules (MNs) in branch duct IPMN (BD-IPMN). METHODS: Among the 402 registered patients with BD-IPMN on long-term follow-up at 10 institutions in Japan, 53 patients with MNs of less than 10 mm in height detected by endosonography were included in this study. The morphological changes of the BD-IPMN in these patients and histologic findings of the resected specimen were investigated. RESULTS: The median height of the MNs at the initial diagnosis was 3 mm (range, 1-8 mm), and 12 (23%) of the 53 patients showed an increase in the height of the MNs during follow-up (mean duration, 42 months). Six patients underwent surgery because of an increase in the height of MNs, yielding high-grade dysplasia in 1 patient and low-grade dysplasia in 5 patients. No patients developed invasive carcinoma derived from IPMN, and distinct pancreatic ductal adenocarcinoma developed in 1 (2%) patient. The incidence of the development of malignancy in BD-IPMNs, including distinct pancreatic ductal adenocarcinoma, was similar to that of those without MNs. CONCLUSIONS: In patients who have BD-IPMN with MNs of less than 10 mm in height, observation instead of immediate resection is considered to be possible.

Stage II/III cancer of the rectosigmoid junction: an independent tumor type?

The 5-year relapse-free survival rate (5Y-RFS) and 5-year overall survival rate (5Y-OS) were investigated in 766 patients with stage II/III colorectal cancer (CRC). The Stage II group included 283 patients with colon cancer (CC), 40 patients with rectosigmoid junction cancer (RSC), and 74 patients with rectal cancer (RC), while the Stage III group comprised 226 patients with CC, 52 patients with RSC, and 91 patients with RC. Stage III patients with RC were further divided into 68 patients with Ra cancer (Ra, rectum/above the peritoneal reflection) and 23 patients with Rb cancer (Rb, rectum/below the peritoneal reflection). Then the 5Y-RFS and 5Y-OS were calculated for each category or subcategory. The 5Y-RFS/5Y-OS was 80.3/80.6% for Stage II patients and 63.7% (p<0.001)/66.2% (p<0.001) for Stage III patients. In the Stage II group, the survival rates were 82.9/81.2% for CC, 77.6/74.8% for RSC, and 72.9/80.5% for RC, with no significant differences between each category. In the Stage III group, the survival rates were 69.3/72.8% for CC, 71.6/77.7% for RSC, and 46.5/46.2% for RC. There was no significant difference of survival for CC vs. RSC, but significant differences were noted for CC vs. RC (p<0.001/p<0.001) and RSC vs. RC (p=0.008/p=0.007). In the Stage III group, survival rates were 71.6/77.7% for RSC, 47.6/44.8% for Ra, and 45.7/51.3% for Rb, with significant differences for RSC vs. Ra (p=0.013/p=0.005) and RSC vs. Rb (p=0.026/p=0.180), but not for Ra vs. Rb. These results suggest that Stage II/III RS cancer should be classified as colon cancer and should not be considered an independent tumor type.

Is the T1/2N1 (≤3 nodes) category actually stage IIIA (TNM)/IIIa (Japanese classification) in patients with primary colorectal cancer?

The 5-year relapse-free survival rate (5Y-RFS) and the 5-year overall survival rate (5Y-OS) were calculated for 972 patients (stage I, 206 patients; stage II, 396 patients; stage III, 370 patients). We divided the stage III group into 259 patients with IIIa/N1 disease (≤3 positive nodes) and 111 patients with IIIb/N2 disease (≥4 positive nodes) according to the Japanese classification. The IIIa/N1 and IIIb/N2 categories were each subdivided into T1/2 (stage IIIa, 45 cases; IIIb, 9 cases) and ≥T3 (stage IIIa, 214 cases; IIIb, 102 cases) according to the TNM classification, and 5Y-RFS and 5Y-OS were compared between each subcategory and each group. The 5Y-RFS/5Y-OS values calculated for each stage were as follows: stage I, 94.0/90.7%; stage II, 80.5/81.1%; stage III, 63.5/65.7%. When stage IIIa was compared with IIIb, we obtained 67.9/72.0% for stage IIIa and 53.6% (p=0.001)/50.4% (p<0.001) for stage IIIb. For stage IIIa vs. IIIb in the ≥T3 category, we obtained 63.1/68.5% for stage IIIa and 51.9% (p=0.010)/49.0% (p=0.008) for stage IIIb. For stage IIIa vs. IIIb in the T1/2 category, we obtained 92.1/92.0% for stage IIIa and 72.9% (p=0.040)/63.5% (p=0.003) for stage IIIb. There were significant differences between T1/2 and ≥T3 within stage IIIa (p=0.001/p=0.009), but not within stage IIIb. These results suggest that the T1/2N1 category of colorectal cancer should be classified as a subcategory of stage IB/Ib rather than stage IIIA (TNM)/IIIa (Japanese classification).

Anal function-preserving subtotal intersphincteric resection/partial external sphincteric resection with hybrid 2-port hand-assisted laparoscopic surgery (Mukai's operation) for very low stage I rectal cancer: A case report.

A 62-year-old male patient underwent endoscopic mucosal resection (EMR). Additional hybrid 2-port hand-assisted laparoscopic surgery (HALS) (Mukai's operation) was performed for early rectal cancer located at the distal border of the rectum/below the peritoneal reflection (Rb) region [SM massive invasion/ly+/vertical margin (VM)X] via a small transverse incision, approximately 55 mm long, at the superior border of the pubic bone. After the pelvic floor muscles were dissected by laparoscopy-assisted manipulation, transanal subtotal intersphincteric resection (ISR) was performed under direct vision, securing a margin of more than 15 mm distal to the EMR scar. Partial external sphincteric resection (ESR) was also performed to obtain an adequate VM at the posterior region of the EMR scar. After bowel reconstruction, the layers were sutured transanally and a temporary covering colostomy was created. The resected specimen contained no residual tumor cells without lymph node metastasis. At 3 months after the operation, digital examination revealed good tonus of the anal muscles without stricture. The patient is currently undergoing rehabilitation of his anal sphincter muscles in preparation for the colostomy closure. In conclusion, subtotal ISR combined with partial ESR may decrease the need to perform Miles' operation for T1/2 stage I rectal cancer located at the distal border of the Rb region.

Two-port hand-assisted laparoscopic surgery for the 2-stage treatment of a complete bowel obstruction by left colon cancer: a case report.

A 69-year-old woman presented to her local clinic with vomiting and abdominal distension. Since a bowel obstruction by left colon cancer was suspected due to a marked dilation of the transverse colon, she was referred to our hospital. On admission, an enema disclosed a complete obstruction at the splenic flexure of the colon. An emergency operation was performed, and a temporary loop colostomy was fashioned on the left side of the transverse colon within the range of resection for 2-stage radical surgery. On hospital day 16, a left hemicolectomy D2 was performed by 2-port hand-assisted laparoscopic surgery (2P-HALS) using the stoma as the hand access site, and the tumor was resected along with the removal of the stoma. After surgery, a slight wound infection occurred at the hand access site, but this healed with conservative management. On day 36, she was discharged from hospital. The histological diagnosis was Type 2 circumferential well-differentiated adenocarcinoma with local peritoneal dissemination. Our experience suggests that 2-stage surgery combined with 2P-HALS is applicable even to a large obstructing left colon cancer. This method is less invasive, safe and achieves excellent results, including a good cosmetic outcome.

Pancreaticojejunostomy using duct-to-mucosa anastomosis without a stenting tube.

BACKGROUND PURPOSE: There is a high risk of anastomotic leakage after pancreaticojejunostomy following pancreaticoduodenectomy in patients with a normal soft pancreas because of the high degree of exocrine function. Therefore, pancreaticojejunostomy is generally performed using a stenting tube (stented method). However, pancreaticojejunostomy with a certain duct-to-mucosa anastomosis does not always require a stenting tube, even in patients with a normal soft pancreas. Recently, we have performed pancreaticojejunostomy with duct-to-mucosa anastomosis without a stenting tube (nonstented method) and obtained good results. METHODS: The point of this technique is to maintain adequate patency of the anastomosis using a fine atraumatic needle and monofilament thread. The results of end-to-side pancreaticojejunostomy of the normal soft pancreas using the nonstented method (n = 123) were compared with those using the stented method (n = 45). RESULTS: There were no differences in background characteristics between the groups, including age, gender, and disease. The mean times to complete pancreaticojejunostomy were around 30 min in the two groups and the rates of morbidity and leakage of pancreaticojejunostomy were 26.8% and 5.7% in the nonstented group and 22.2% and 6.7% in the stented group, respectively. These differences were not statistically significant. One patient in the stented group died of sepsis following leakage of pancreaticojejunostomy. There were also no significant differences in the mean time to initiation of solid food intake or postoperative hospital stay. CONCLUSIONS: In conclusion, complete pancreaticojejunostomy using duct-to-mucosa anastomosis for a normal soft pancreas does not require a stenting tube. This nonstented method can be considered one of the basic procedures for pancreaticojejunostomy because of its safety and certainty.