Feasibility of middle colic artery as a landmark for superior mesenteric artery - first approach in laparoscopic pancreatoduodenectomy: a prospective study.

BACKGROUND: SMA-first approach in pancreatoduodenectomy (PD) has been widely applied in open surgery as well as laparoscopy. Finding the superior mesenteric artery (SMA), inferior pancreatoduodenal artery (IPDA), first jejunal artery (J1A) has become a great challenge in laparoscopic PD (LPD). Meanwhile, exposing the midde colic artery (MCA) might be a feasible approach to determine SMA, IPDA, and J1A. Our study aims to find the anatomical correlation between MCA and SMA, IPDA, J1A, especially in SMA-first approach LPD from the left. METHODS: Uncontrolled clinical trial with 33 patients undergoing LPD had preoperative contrast abdominal CT scan to analyze the anatomical relevance between MCA and SMA, J1A, IPDA. The operation was performed starting with exposing MCA in advance to find SMA, J1A and IPDA. The data was analyzed by SPSS 25.0. RESULTS: 90.9% of MCA started at 12-3 o'clock from SMA, the mean distance from the SMA root to the MCA and J1A was 56.4 mm and 37.4 mm, respectively. The distance between SMA and J1A was 19 mm. 72.7% J1A started at 9-12 o'clock, 69.7% J1A and IPDA had a common trunk. 78.8% IPDA started at 3-6 o'clock. 100% of the cases had J1A controlled intraoperatively, 81.8% for IPDA when approached from the left, 3% had MCA injury. The mean time to approach from the left was 98 min, median blood loss was 100 ml. CONCLUSION: Exposing MCA first helps determine SMA, J1A and IPDA safely, efficiently and faciliates SMA-first approach LPD from the left and complete dissection of the mesopancreas and lymph nodes.

Pancreaticoduodenectomy with superior mesenteric artery first-approach combined total meso-pancreas excision for periampullary malignancies: A high-volume single-center experience with short-term outcomes.

Backgrounds/Aims: Pancreaticoduodenectomy (PD) is the only radical treatment for periampullary malignancies. Superior mesenteric artery (SMA) first approach combined with total meso-pancreas (MP) excision was conducted to improve the oncological results. There has not been any previous research of a technique that combines the SMA first approach and total MP excision with a detailed description of the MP macroscopical shape. Methods: We prospectively assessed 77 patients with periampullary malignancies between October 2020 and March 2022 (18 months). All patients had undergone PD with SMA first approach combined total MP excision. The perioperative indications, clinical data, intra-operative index, R0 resection rate of postoperative pathological specimens (especially mesopancreatic margin), postoperative complications, and follow-up results were evaluated. Results: The median operative time was 289.6 min (178-540 min), the median intraoperative blood loss was 209 mL (30-1,600 mL). Microscopically, there were 19 (24.7%) cases with metastatic MP, and five cases (6.5%) with R1-resection of the MP. The number of lymph nodes (LNs) harvested and metastatic LNs were 27.2 (maximum was 74) and 1.8 (maximum was 16), respectively. Some (46.8%) patients had pancreatic fistula, but mostly in grade A, with 7 patients (9.1%) who required re-operations. Some 18.2% of cases developed postoperative refractory diarrhea. The rate of in-hospital mortality was 1.3%. Conclusions: The PD with SMA first approach combined TMpE for periampullary malignancies was effective in achieving superior oncological statistics (rate of MP R0-resection and number of total resected LNs) with non-inferior short-term outcomes. It is necessary to evaluate survival outcomes with long-term follow-up.

Design of a lightweight magnetizer to enable a portable circumferential magnetic flux leakage detection system.

We proposed a lightweight magnetizer toward the realization of a portable circumferential magnetic flux leakage (MFL) inspection tool for the detection of longitudinal defects with a linear motion between pipes and the inspection tool. The proposed magnetizer consists of four permanent magnetic poles constructing a configuration in which the like poles are separated by a θ angle ranging from 30° to 60° and the opposite poles are separated by a supplemental angle of θ. The distribution of the magnetic field generated by this magnetizer and caused by defects was studied by finite element methods as well as by experimental measurements. The results reveal that the new magnetizer has advantages of high amplitude and good uniformity of magnetic field over the state-of-the-art ones with configurations of two facing poles or quadrupole geometries. With the new magnetizer, the theoretical and experimental results show that the magnetization in the pipe increases slightly with the θ angle, but the uniformity of magnetization in the pipe and the magnetic field on the surface of pipe decrease dramatically with this angle. So, the optimum angle θ is proposed at around 30°-40°. The finite element calculation and the measurements of the MFL signal caused by artificial defects evidence the capabilities in detecting shallow longitudinal defects of the MFL inspection tool with our novel magnetizer.