Mechanical Resistance Curves of the NTLC75 Linear Stapler During Barcelona Ileotransverse Anastomosis (NTLC75-ITA)

Adults undergoing elective right colectomy with a Barcelona ileotransverse anastomosis using NTLC75/SR75 as standard clinical care. Relative mechanical signals are recorded passively during two close-only calibration closures without firing and two standard stapler activations.

An external DF9-40 sensor mounted on the NTLC75 handle passively records relative mechanical signals. One close-only calibration recording is obtained on double-walled small bowel and one on double-walled colon on the resection-specimen side, outside the tumor and resection margins, with the anvil toward the mesentery, without firing. Signals are also recorded during standard ITA channel formation (anvil in colon; reload jaw in small bowel; no cross-stapling) and final closure (tip toward small bowel; knife travel from colon to small bowel across two existing staple lines). The signal is not shown to the surgeon and does not affect clinical care.

Number and percentage of all 40 enrolled participants with a complete and technically valid final cross-stapling signal record. A valid record includes a complete forward branch, an identifiable reference return branch, no peak-obscuring saturation, no loss of sensor contact, and successful application of the locked signal-processing algorithm. Missing or invalid records remain in the denominator. Prespecified feasibility target: at least 35 of 40 participants.

Routine-care serum C-reactive protein in mg/L, analyzed continuously in association with the normalized maximum amplitude of the final cross-stapling forward branch using a scatterplot, Pearson or Spearman correlation, and simple linear regression.

Maximum baseline-corrected relative signal amplitude during complete stapler closure on the double-walled small bowel located on the resection-specimen side, without firing. Reported in relative signal units.

Maximum baseline-corrected amplitude of each forward and return signal branch, calculated separately for the ileotransverse anastomotic-channel and final cross-stapling activations. Reported in relative signal units.

Two independent raters blinded to C-reactive protein values and clinical outcomes classify technical validity, curve morphology, sticking, and irregularity for the ileotransverse anastomotic-channel and final cross-stapling recordings. Agreement between the two initial categorical ratings is quantified using Cohen's kappa before consensus resolution.

Routine-care serum C-reactive protein concentration recorded separately on postoperative days 1 and 3 and reported in mg/L. The prespecified association between postoperative-day-3 CRP and the normalized final cross-stapling maximum remains the second primary outcome.

Highest Clavien-Dindo grade assigned to any postoperative complication experienced by each participant through postoperative day 90. Participants without a complication are recorded as having no Clavien-Dindo complication.

Number and percentage of participants with anastomotic leak, anastomotic bleeding, perianastomotic collection or abscess, anastomosis-related radiologic or endoscopic intervention, reoperation, or surgical revision. Each event type is reported separately.

Number of calendar days from the index operation to discharge from the index hospitalization.

Maximum baseline-corrected relative signal amplitude during complete stapler closure on the double-walled colon located on the resection-specimen side, without firing. Reported in relative signal units.

Maximum baseline-corrected relative signal amplitude during the closing phase preceding the standard stapler activation used to form the ileotransverse anastomotic channel without cross-stapling. Reported in relative signal units.

Maximum baseline-corrected relative signal amplitude during the closing phase preceding the final cross-stapling activation. Reported in relative signal units.

Position of the maximum baseline-corrected amplitude within each signal branch, expressed as a percentage of that branch's total duration from 0% to 100%. Calculated separately for the forward and return branches of both activations.

Actual elapsed duration of each forward and return signal branch, calculated separately for the ileotransverse anastomotic-channel and final cross-stapling activations. Reported in seconds from the preserved raw timestamps.

Number of signal peaks identified by the locked signal-processing algorithm in each 200-point normalized-time branch. Calculated separately for the forward and return branches of both activations.

Maximum positive slope of each 200-point normalized-time signal branch, calculated using the locked signal-processing algorithm. Reported in relative signal units per normalized-time point and calculated separately for both activations.

Area under each baseline-corrected 200-point normalized-time signal branch, calculated separately for the forward and return branches of both activations. Reported in relative signal units multiplied by normalized time.

Standard deviation of the baseline-corrected amplitudes across each 200-point normalized-time signal branch. Calculated separately for the forward and return branches of both activations and reported in relative signal units.

Routine-care peripheral blood leukocyte count recorded separately on postoperative days 1 and 3 and reported as ×10^9/L.

Routine-care peripheral blood absolute neutrophil count recorded separately on postoperative days 1 and 3 and reported as ×10^9/L.

Routine-care peripheral blood absolute lymphocyte count recorded separately on postoperative days 1 and 3 and reported as ×10^9/L.

Neutrophil-to-lymphocyte ratio calculated from the absolute neutrophil and lymphocyte counts obtained on the same postoperative day. Recorded separately on postoperative days 1 and 3 and reported as a unitless ratio.

Routine-care serum albumin concentration recorded separately on postoperative days 1 and 3 and reported in g/L.

Routine-care serum creatinine concentration recorded separately on postoperative days 1 and 3 and reported in µmol/L.

Laboratory-reported estimated glomerular filtration rate recorded separately on postoperative days 1 and 3 and reported in mL/min/1.73 m².

Number and percentage of participants experiencing at least one major postoperative complication, defined as Clavien-Dindo grade III, IV, or V.

Comprehensive Complication Index score calculated from all postoperative complications experienced by each participant through postoperative day 90. Reported on the standard continuous scale from 0, indicating no complication, to 100, indicating death.

Number and percentage of participants with at least one unplanned all-cause hospital readmission by postoperative day 30.

Number and percentage of participants undergoing at least one unplanned surgical reoperation for any cause by postoperative day 30.

Number and percentage of participants who die from any cause by postoperative day 30.

Number and percentage of participants who die from any cause by postoperative day 90.