Purpose: Splenic flexure mobilization (SFM) is occasionally utilized during sigmoidectomy to facilitate a tension-free colorectal anastomosis. Present literature regarding its use, safety, and efficacy predominantly evaluates traditional laparoscopic vs. open techniques, thus not adequately representing the current minimally invasive surgical landscape. Methods: This retrospective cohort analysis evaluated SFM during sigmoidectomy for diverticular disease via traditional laparoscopic, single-incision laparoscopic, and robotic techniques at a United States academic institution from 2019 to 2022. Primary outcomes were the rate of SFM, independent predictors, and short-term outcomes. Results: A total of 117 patients underwent sigmoidectomy for diverticulitis by six colorectal surgeons, of whom 27 underwent SFM. SFM was associated with higher rates of complicated diverticulitis (85.2% vs. 46.7%, p < 0.001), including abscess (55.6% vs. 33.3%, p = 0.037) and fistulae (59.3% vs. 17.8%, p < 0.001). Presence of a fistula was an independent predictor of SFM by logistic regression (odds ratio [OR], 5.886; p < 0.001). Mobilization was associated with more concomitant surgical procedures (66.7% vs. 28.9%, p < 0.001). There was a significant association between SFM and conversion to open approach (14.8% vs. 3.3%, p = 0.049), longer length of stay (4.2 ± 2.8 days vs. 3.6 ± 4.3 days, p = 0.041), and increased operative time (241.7 ± 76.4 minutes vs. 199.2 ± 75.7 minutes). There was no difference in 30-day morbidity/mortality. Conclusion Routine SFM can be considered in minimally invasive sigmoidectomy for complicated diverticulitis without significant impact on 30-day morbidity/mortality regardless of surgical approach and may be anticipated preoperatively, particularly when a fistula is present.

To investigate the mechanism by which the C-terminus (4,938-5,037) of the ryanodine receptor 1 (RyR1) homo-tetramerizes, forming a functional Ca2+ -release channel, the structural requirements for the tetramerization were studied using site-directed mutagenesis. Alanine-substitutions at five charged residues, E4976, H5003, D5026, E5033 and D5034, significantly decreased the formation of homo-dimers (reduced by > 50%). Interaction between the C-terminus and cytoplasmic loop I (4,821-4,835) required two positively charged residues, H4832 and K4835. Based on the predicted protein secondary structures, all seven charged residues are located in random coils. Paired alanine-substitutions at six negatively charged residues (E4942A/D4953A, D4945A/E4952A and E4948A/ E4955A) of the alpha-helix (4,940-4,956) in the C-terminus increased homo-dimerization. Therefore, the homo-tetramerization of RyR1 may be mediated by intra- and/or inter-monomer electrostatic interactions among the C-terminal charged residues in random coils or in an alpha-helix.
Amino Acid Sequence ; Animals ; Dimerization ; Models, Molecular ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Protein Structure, Quaternary ; Protein Structure, Secondary ; Rabbits ; Recombinant Fusion Proteins/chemistry/genetics ; Ryanodine Receptor Calcium Release Channel/*chemistry/genetics ; Sequence Homology, Amino Acid ; Static Electricity