Anatomy study and clinical application of minimally invasive anterior lumbar retroperitoneal approach / 中华骨科杂志

Objective:To explore the ideal method of minimally invasive anterior lumbar extraperitoneal approach.Methods:Twenty-one adult embalmed cadavers underwent longitudinal incision near the left rectus abdominis, the extraperitoneal space and peritoneal characteristics were observed; the L 2-S 1 disc was exposed through extraperitoneal approach, and the relationship between the anterior large vessels and the disc was observed. One hundred adult abdominal CT were collected to measure the distance between the extraperitoneal fat of anterior abdominal wall and the rectus abdominis and the anterior midline at L 2-S 1 segment. One hundred and fifty adult lumbar MRI were collected to measure the distance between the anterior great vessels and the anterior midline of the intervertebral disc. Fifty-six cases of lumbar fusion were performed by minimally invasive anterior lumbar extraperitoneal approach, including 25 males and 31 females, aged 29-71 years. L 2-L 4 in 8 cases was performed by left rectus abdominis oblique incision, and L 4-S 1 in 48 cases was performed by median left transverse incision, with a length of about 8 cm, the complications related to the surgical approach were evaluated. Results:L 2-L 4 was proximal to the arcuate line, the posterior sheath of rectus abdominis adhered to the peritoneum, which was easy to rupture when separated; the peritoneum gradually thickened from the outer edge of the sheath of rectus abdominis and extraperitoneal fat appears. L 4-S 1 could be exposed distal to the arcuate line, the posterior side of rectus abdominis was extraperitoneal fat, the extension of arcuate line to the lateral abdominal wall would be slightly separated proximally, and there were multiple iliopsoas veins in the medial side of psoas major muscle. L 5S 1 was between the right common iliac artery and the left common iliac vein far, the median sacral vessel was small or absent, and the sympathetic nerve was to the left. Extraperitoneal fat appeared 36.2±9.9 mm, 35.2±11.6 mm and 27.6±11.2 mm away from the outer edge of rectus abdominis at L 2, 3, L 3, 4 and L 4, 5 segments respectively, and covered the posterior side of rectus abdominis and reached the midline at L 5S 1 segment. The left edge of abdominal aorta was 14.9±5.1 mm, 13.9±4.6 mm and 19.7±5.9 mm away from the midline at L 2, 3, L 3, 4 and L 4, 5 level respectively; the inferior vena cava was located on the right side of the midline at L 2, 3 and L 3, 4 level, crossed the midline 4.6±8.7 mm at L 4, 5 level. At L 5S 1 level, the left common iliac vein and the right common iliac artery were 14.6±6.8 mm and 17.6±5.3 mm away from the midline respectively. Seventy-six patients were successfully and fully exposed by small incision through extraperitoneal approach. 1 case of L 4, 5 had iliac lumbar vein tear and hemostasis with bipolar electrocoagulation. The operation time was 70-120 min, with an average of 90 min; Intraoperative bleeding was 15-70 ml, with an average of 30 ml. No severe complication such as nerve and great vessel injury occurred. Conclusion:Minimally invasive lumbar anterior retroperitoneal approach has small trauma and sufficient exposure with good feasibility. L 2-L 4 can be exposed with supine position and oblique incision next to the left rectus abdominis muscle, and L 4~S 1 with French position and median left transverse incision.

A new proposed sweet potato starch granule structure--pomegranate concept.

There are two competing concepts about organization of starch granule, fibrillar concept (or amylopectin clustering concept) and blocklet concept. A new micrograph of gelatinized sweet potato starch mixed with lactose might combine the two concepts and recover the mysterious structure of starch granule. Here we propose a possible granule structure of sweet potato starch by analyzing its gelatinization micrographs mixed with different carbohydrates. As the structure of pomegranate, out-layer of granule is equivalent to skin of pomegranate, blocklets are same to garnet of pomegranate, the amylopectin clusters with one reducing end at hilum, equivalent to primary body of pomegranate, constitute the basic structure of granule, in the special parts of the clusters, lots of blocklets form and increase, very like the born of garnet of pomegranate. At the same time double helix appears in blocklets, the arrangements of blocklets, same as garnet in pomegranate, form the semi-crystalline growth rings. The crystal type of starch is determined by arrangement of blocklet on it, hexagonal for A type, monoclinic for B type.

The effects of electrolysis at room temperature on retrogradation of sweet potato starch.

The effects of electrolysis at room temperature on formation of sweet potato retrograded starch were studied by photographic method in the paper. The optimal parameters of electrolytic preparation of sweet potato retrograded starch were determined. The ratio between sweet potato starch and water was 10 g/100 mL with addition of NaCl 1.0 g/100 mL, pH value of the solution was 6.0 and the solution was electrolyzed for 30 min at 90 V at room temperature, then it was stored at 4°C for 24h after being autoclaved for 30 min at 120°C, the retrogradation rate of sweet potato starch at this condition was 33.1%, which is 138% higher than that of control group. Four possible reasons are put forward to explain the results.