Consequences of a Surveillance Strategy for Side-branch Intraductal Pancreatic Mucinous Neoplasms: Long-term Follow-up of One Thousand Cysts.

OBJECTIVE: To quantify the rate of progression in surveilled cysts and assess what factors should indicate delayed resection. BACKGROUND: Side-branch intraductal papillary mucinous neoplasms (SB-IPMNs) are increasingly discovered, making it challenging to identify which patients require resection, thus avoiding inappropriate treatment. Most incidental lesions are surveyed, yet the consequences of that decision remain uncertain. METHODS: A prospectively maintained database of pancreatic cystic neoplasms was queried for patients with SB-IPMN. Patients with ≥2 imaging studies >6 months apart were included. Clinically relevant progression (CR-progression) was defined by symptoms, worrisome/high-risk stigmata, or invasive cancer (IC). Growth ≥5 mm in 2 years is considered CR-progression; size ≥3 cm alone is not. RESULTS: Between 1997 and 2023, 1337 patients were diagnosed with SB-IPMN. Thirty-seven (2.7%) underwent up-front surgery; 1000 (75.0%) had >6 months of surveillance.The rate of CR-progression was 15.3% (n = 153) based on size increase (n = 63, 6.3%), main-duct involvement (n = 48, 4.8%), symptoms (n = 8, 5.0%), or other criteria (n = 34, 3.4%). At a median follow-up of 6.6 years (interquartile range: 3.0-10.26), 17 patients (1.7%) developed IC. Those with CR-progression developed IC in 11.1% (n = 17) and high-grade dysplasia (HGD) in 6.5% (n = 10). Nearly half of the cancers were not contiguous with the surveyed SB-IPMN.Size ≥3 cm was not associated with HGD/IC ( P = 0.232). HGD/IC was least common in CR-progression determined by size growth (6.3%) versus main-duct involvement (24%) or other (43%, P < 0.001)Patients with CR-progression demonstrated improved survival (overall survival) with resection on time-to-event ( P < 0.001) and multivariate Cox regression (hazard ratio = 0.205, 0.096-0.439, P < 0.001) analyses. Overall survival was not improved with resection in all patients ( P = 0.244). CONCLUSIONS: CR-progression for SB-IPMNs is uncommon, with the development of cancer anywhere in the pancreas being rare. Initial size should not drive resection. Long-term and consistent nonoperative surveillance is warranted, with surgery currently reserved for CR-progression, knowing that the majority of these still harbor low-grade pathology.

Natural history and growth prediction model of pancreatic serous cystic neoplasms.

OBJECTIVE: Serous cystic neoplasms (SCN) are benign pancreatic cystic neoplasms that may require resection based on local complications and rate of growth. We aimed to develop a predictive model for the growth curve of SCNs to aid in the clinical decision making of determining need for surgical resection. METHODS: Utilizing a prospectively maintained pancreatic cyst database from a single institution, patients with SCNs were identified. Diagnosis confirmation included imaging, cyst aspiration, pathology, or expert opinion. Cyst size diameter was measured by radiology or surgery. Patients with interval imaging ≥3 months from diagnosis were included. Flexible restricted cubic splines were utilized for modeling of non-linearities in time and previous measurements. Model fitting and analysis were performed using R (V3.50, Vienna, Austria) with the rms package. RESULTS: Among 203 eligible patients from 1998 to 2021, the mean initial cyst size was 31 mm (range 5-160 mm), with a mean follow-up of 72 months (range 3-266 months). The model effectively captured the non-linear relationship between cyst size and time, with both time and previous cyst size (not initial cyst size) significantly predicting current cyst growth (p < 0.01). The root mean square error for overall prediction was 10.74. Validation through bootstrapping demonstrated consistent performance, particularly for shorter follow-up intervals. CONCLUSION: SCNs typically have a similar growth rate regardless of initial size. An accurate predictive model can be used to identify rapidly growing outliers that may warrant surgical intervention, and this free model (https://riskcalc.org/SerousCystadenomaSize/) can be incorporated in the electronic medical record.

Impact of autotransfusion on recurrence of colorectal cancer liver metastasis: Long-term follow-up of patients undergoing curative intent hepatectomy.

INTRODUCTION: Colorectal cancer liver metastasis (CRLM) occurs in upto 50% of cases and drives patient outcomes. Up-front liver resection is the treatment of choice in resectable cases. There is no consensus yet established as to the safety of intraoperative autotransfusion in liver resection for CRLM. METHODS: Patients undergoing curative-intent hepatectomy for CRLM at a single quaternary-care institution from 1999 to 2016 were included. Demographics, surgical variables, Fong Clinical Risk Score (FCRS), use of intraoperative auto and/or allotransfusion, and survival data were analyzed. Propensity score matching (PSM) was performed accounting for allotransfusion, extent of hepatectomy, FCRS, and systemic treatment regimens. RESULTS: Three-hundred sixteen patients were included. The median follow-up was 10.4 years (7.8-14.1 years). The median recurrence-free survival (RFS) and overall survival (OS) in all patients were 1.6 years (interquartile range: 0.63-6.6 years) and 4.4 years (2.1-8.7), respectively.  Before PSM, there was a significantly reduced RFS in the autotransfusion group (0.96 vs. 1.73 years, p = 0.20). There was no difference in OS (4.11 vs. 4.44 years, p = 0.118). Patients in groups of FCRS 0-2 and 3-5 both had reduced RFS when autotransfusion was used (p = 0.005). This reduction in RFS was further found when comparing autotransfusion versus no autotransfusion within the FCRS 0-2 group and within the FCRS 3-5 group (p = 0.027). On Cox-regression analysis, autotransfusion (hazard ratio = 1.423, 1.028-2.182, p = 0.015) remained predictive of RFS. After PSM, there were no differences in FCRS (p = 0.601), preoperative hemoglobin (p = 0.880), allotransfusion (p = 0.130), adjuvant chemotherapy (p = 1.000), immunotherapy (p = 0.172), tumor grade (p = 1.000), use of platinum-based chemotherapy (p = 0.548), or type of hepatic resection (p = 0.967). After matching, there was a higher rate of recurrence with autotransfusion (69.0% vs. 47.6%, p = 0.046). There was also a reduced time to recurrence in the autotransfusion group compared with the group without (p = 0.006). There was no difference in OS after PSM (p = 0.262). CONCLUSION: Autotransfusion may adversely affect recurrence in liver resection for CRLM. Until further studies clarify this risk profile, the use of intraoperative autotransfusion should be critically assessed on a case-by-case basis only when other resuscitation options are not available.

Lessons learned and keys to success: Provider experiences during the implementation of virtual oncology tumor boards in the era of COVID-19.

BACKGROUND AND OBJECTIVES: The COVID-19 pandemic required rapid adaptation of multidisciplinary tumor board conferences to a virtual setting; however, there are little data describing the benefits and challenges of using such a platform. METHODS: An anonymous quality improvement survey was sent to participants of tumor board meetings at a large academic institution. Participants answered questions pertaining to the relative strengths and weaknesses of in-person and virtual settings. RESULTS: A total of 335 responses (23.3% response rate) were recorded, and 253 met inclusion criteria. Respondents represented 25 different tumor board meetings, with colorectal, breast, and liver (18.6%, 17.0%, and 13.0%, respectively) being the most commonly attended. Virtual tumor boards were equivalent to in-person across 9 of 10 domains queried, while a virtual format was preferred for participation in off-site tumor boards. The lack of networking opportunities was ranked by physicians to be a significant challenge of the virtual format. Consistent leadership and organization, engaged participation of all attendees, and upgrading technology infrastructure were considered critical for success of virtual meetings. CONCLUSIONS: The implementation of virtual tumor board meetings has been associated with numerous challenges. However, improving several key aspects can improve participant satisfaction and ensure excellent patient care.

Long term assessment of antibiotic prophylaxis and biliary microbiome in pancreaticoduodenectomy.

INTRODUCTION: Surgical site infections (SSI) can represent a major complication of pancreaticoduodenectomy (PD). We summarize the outcomes of process improvement efforts to reduce the SSI rates in PD that includes replacing Cefazolin with Ceftriaxone-Metronidazole as antibiotic prophylaxis. Additional efforts included current assessment of biliary microbiome and potential prophylactic failures based on bile cultures and suspected antibiotic allergies. METHOD: A single-center review of PD patients from January-2012 to March-2021. Study groups were divided into Pre and Post May-2015 (Group 1 and 2, respectively) when Ceftriaxone-Metronidazole prophylaxis and routine intraoperative cultures were standardized. Univariate and multivariable analyses were conducted to assess groups' differences and association with SSI. RESULTS: Six hundred ninety patients identified [267(38.7%) and 423(61.3%) in Group 1 and Group2, respectively]. After antibiotic change, SSI rates decreased from 28.1% to 16.5% (incisional: 17.6%-7.5%, organ-space or abscess: 17.2%-13.0%), Group 1 and Group 2, respectively, P<0.001. Ceftriaxone-Metronidazole was used in 75.9% of patients Group 2. When adjusting for other covariates, an SSI-decrease was associated only with Ceftriaxone-Metronidazole (OR 0.34, P<0.001). CONCLUSIONS: Ongoing process improvement has resulted in decreased SSIs with Ceftriaxone-Metronidazole prophylaxis. The benefit of Ceftriaxone-Metronidazole is independent of the biliary microbiome. Improving prophylaxis for those with suspected penicillin allergy is warranted.

Short- and long-term surgical outcomes of total pancreatectomy with islet autotransplantation: A comparative analysis of surgical technique and intraoperative heparin dosing to optimize outcomes.

BACKGROUND: Total pancreatectomy with islet autotransplantation (TP-IAT) is an uncommon surgical procedure with unique perioperative management. We evaluated the short- and long-term morbidity and mortality of TP-IAT to optimize surgical technique and heparin dosing during islet autotransplantation. METHODS: Eighty patients with chronic pancreatitis undergoing TP-IAT were reviewed. Primary outcome was to evaluate morbidity and mortality based on operative technique: classic (resection of antrum) vs pylorus-preserving. Secondary outcome was to evaluate the effect of heparin dosing (<60 vs ≥ 60 units/kg) during islet autotransplantation on postoperative hemorrhage and portal vein thrombosis (PVT) rates. RESULTS: There was no 90-day mortality, and median length of stay was 9 days. All patients underwent an open operation with 53 (66%) pylorus-preserving resections. The 30-day morbidity rate was 39%, with no difference between operative technique (p = 0.82). The median dose was different for each heparin group (<60: 52 units/kg vs ≥ 60: 66 units/kg, p < 0.0001). No difference was observed in postoperative hemorrhage rates between heparin groups (<60: 9% vs ≥ 60: 9%, p = 0.97), with no known incidence of PVT. Median follow-up was 36 months (IQR, 14-71). Morbidity >30 days after TP-IAT was 43% with a higher rate in the pylorus-preserving group (55% vs 15%, p < 0.0001), mainly attributed to marginal ulcer formation (15% vs 0%, p = 0.03). CONCLUSIONS: A classic TP-IAT technique should be universally adopted to achieve optimal outcomes, particularly to prevent the formation of marginal ulcers. When considering PVT versus postoperative hemorrhage risk, a lower heparin dose nearing 50 units/kg is optimal. These findings highlight potential areas for future improvement.

Survival impact based on hepatic artery lymph node status in pancreatic adenocarcinoma: A study of patients receiving modern chemotherapy.

BACKGROUND: Chemotherapy for pancreatic adenocarcinoma (PDAC) has significantly improved in recent years. While the involvement of the hepatic artery lymph node (HALN; station 8a lymph node) likely represents advanced disease, a comparison to patients with metastases on modern chemotherapy is lacking. METHODS: Patients who underwent pancreatoduodenectomy with HALN sent for pathologic review at a single institution from 2003 to 2018 were reviewed. Patients who presented with liver-only metastases at the time of PDAC diagnosis (Stage IV) and received chemotherapy were identified. Multivariate Cox proportional hazards regression modeling was utilized and overall survival (OS) was estimated using Kaplan-Meier analysis. RESULTS: Of the 112 patients with a HALN sent for analysis, 17 (15%) were positive and 13 (76%) received chemotherapy. Ninety-four stage IV patients were identified and were significantly more likely to have received a multiagent rather than single-agent chemotherapy regimen compared to HALN positive patients (79.8% vs. 38.5%, p < .001). Median OS was significantly longer in all patients who underwent surgical resection, regardless of HALN status, compared to stage IV patients. CONCLUSIONS: Patients undergoing pancreatoduodenectomy with HALN positivity have significantly improved OS compared to patients with stage IV disease. HALN involvement does not significantly alter survival among resected patients and does not warrant preoperative endoscopic ultrasound-guided biopsy.

Tumor Size Combined With CA-19 Level Improves Prediction of Survival of Patients With Pancreatic Adenocarcinoma Undergoing Perioperative Chemotherapy and Resection.

BACKGROUND AND OBJECTIVE: Five-year survival in pancreatic adenocarcinoma is less than 20%. While previous studies have postulated that a carbohydrate antigen 19-9 (CA19-9) threshold could predict outcome of resection, the role for CA19-9 in decision-making remains unclear. This study aims to assess whether CA19-9 levels combined with tumor size improve prediction of post-resection survival. METHOD: A retrospective analysis was conducted on 109 patients with pancreatic adenocarcinoma who underwent perioperative chemotherapy followed by resection. The primary outcome of mortality was, divided into short (<1 year) or prolonged (>2 years). Univariate and multivariable analyses compared the tumor size-adjusted CA19-9 between the outcome groups. RESULTS: Twenty-seven (24.78%) and eighty-two (75.23%) patients were in the short survival and prolonged-survival groups, respectively. The mean CA19-9 was significantly greater in the short vs prolonged group (P < .001). Analyzing CA19-9 level by tumor size, the association of high CA19-9 and short survival was significant for small (≤2 cm) and large tumor (>4 cm), but not for intermediate-size tumors (2-4 cm). Adjusting for preoperative variable did not change this association. CONCLUSION: CA 19-9 in combination with tumor size better identifies patients with prolonged post-resection survival. This prediction is most accurate in patients with either small (≤2 cms) or large (>4 cms) tumors compared to intermediate-size tumors.

Disease progression of side-branch intraductal papillary mucinous neoplasms following solid organ transplant.

BACKGROUND: Branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) are becoming more prevalent with advanced medical imaging and account for most of pancreatic cystic neoplasms (PCNs). Most incidental lesions should be surveyed, with resection reserved for specific, high-risk cases. Solid organ transplantation candidates may be high risk of resection before transplant and will require systemic immunosuppression after transplant, which has been theorized to alter the natural history of the IPMN. We aimed to describe the progression in surveilled cysts after solid organ transplantation. METHODS: A prospectively maintained database of PCNs was queried for patients with IPMN. Patients who had received a previous solid organ transplantation and with ≥2 imaging studies >6 months apart after transplantation were included. Clinically relevant (CR) progression was defined as symptoms, worrisome/high-risk stigmata, or invasive carcinoma (IC). Growth ≥5 mm in 2 years is considered CR progression; size ≥3 cm alone is not. RESULTS: Between 1997 and 2023, 252 patients received solid organ transplantation (liver, 86; kidney, 113; and lung, 54) and were diagnosed as having an IPMN. This cohort was compared with a set of 770 patients surveilled for IPMN who did not have previous transplantation. Median follow-up period was 3.7 years (IQR, 1.6-6.8). Moreover, 2 transplant patients (0.8%) developed IC, and 4 developed (1.6%) high-grade dysplasia (HGD). Both were less common in transplant patients than the nontransplant population (IC, 3.3%; HGD, 2.9%), although this was not significant on time-to-event analysis (IC, P = .152; HGD, P = .352). The rate of CR progression was high in the transplant cohort (n = 118; 47%). Features of CR progression included size growth (n = 79; 67%), other worrisome/high-risk stigmata (n = 25; 21%), and new main duct involvement (n = 14; 12%). Compared with the nontransplant (n = 128; 17%), transplant patients had a higher rate of CR progression (P < .001), which was mostly explained by a more frequent size growth (31% vs 9%; P < .001). However, no transplant patients with size growth CR progression developed IC. Moreover, 17 (6.7%) required pancreatic surgery for CR progression after transplant vs 58 (7.5%) in the nontransplant population. Furthermore, 6 resected cysts (35%) harbored high-risk pathology after transplant (IC, 2; HGD, 4) vs 40 (69%) in the general population (P < .001; IC, 29; HGD, 11). CONCLUSION: Malignant transformation of BD-IPMNs is rare despite systemic immunosuppression in solid organ transplant patients. This supports transplantation in patients with IPMN without fear of worsening their risk of pancreatic cancer, although it was associated with a higher risk of disease progression. Patients with IPMNs should be surveilled with yearly scans after transplant, with pancreatic resection reserved for only high-risk features as we continue to define the optimal criteria for those with CR progression.

Intramucosal Extent as a Marker for Advanced Disease and Survival in Gallbladder Adenocarcinoma.

BACKGROUND: Gallbladder cancer (GBC) is the most common biliary tract malignancy and has a poor prognosis. The clinical significance of focal vs diffuse GBC remains unclear. METHODS: A retrospective review was conducted on all patients with non-metastatic GBC at a quaternary care center. Pathology was reviewed, and gallbladder cancer pattern was defined based on the extent of mucosal involvement; "diffuse" if the tumor was multicentric or "focal" if the tumor was only in a single location. Patients undergoing liver resection and portal lymphadenectomy were considered to have definitive surgery. The primary outcome was overall survival and assessed by Kaplan-Meier curves. RESULTS: 63 patients met study criteria with 32 (50.7%) having diffuse cancer. No difference was observed in utilization of definitive surgery between the groups (14 [43.8%] with focal and 12 [38.7%] with diffuse, P = .88). Lymphovascular invasion (P = .04) and higher nodal stage (P = .04) were more common with diffuse GBC. Median overall survival was significantly improved in those with focal cancer (5.1 vs 1.2 years, P = .02). Although not statistically significant, this difference in overall survival persisted in patients who underwent definitive surgery (4.3 vs 2.4 years, P = .70). DISCUSSION: Patients with diffuse involvement of the gallbladder mucosa likely represent a subset with aggressive biology and worse overall survival compared to focal disease. These findings may aid surgeons in subsequent surgical and medical decision-making for patients with GBC.

Correlation between physical status measures and frailty score in patients undergoing pancreatic resection.

BACKGROUND: This study aimed to assess the correlation between validated measures of physical status in a prehabilitation regimen with an established frailty score and analyze changes in these measures after completion of a directed prehabilitation program among patients undergoing elective pancreatic resection. METHODS: Adult patients undergoing pancreatic resection from 2019-2021 were enrolled in a pilot prehabilitation program. Three validated measures of physical status were used: the 6-minute walk test, grip strength, and chair-stand test. The prehabilitation program comprised 7,500 steps, 30 grip strength exercises, and 100 chair-stand exercises daily. Patients' frailty score was calculated using the Modified Johns Hopkins Frailty score. Changes in physical status measures after prehabilitation and postoperative outcomes were compared. RESULTS: Thirty-two patients with a median age of 69.0 years (interquartile range = 59.5-76.3 years) were included. Patients' median duration of participation was 21.5 days (interquartile range = 16-29 days). There was a negative correlation between increasing frailty score and baseline the 6-minute walk test (R2 = 0.17) and chair-stand test (R2 = 0.18). Patients' mean the 6-minute walk test decreased at the end of the prehabilitation program, while grip strength and chair-stand test were unchanged. When stratified by low or intermediate and high frailty scores, the differences in the 6-minute walk test and chair-stand test were unchanged. Hospital duration of stay, complications, and 90-day readmission rates were not different between frailty groups (P > .05). CONCLUSION: Correlation of physical status measures with frailty score suggests only one of these measures is sufficient to estimate patients' preoperative physical status. A longer, more comprehensive prehabilitation program or an expedited operation are likely the best strategies to improve patient outcomes.

Effect of pre-operative opioid exposure on surgical outcomes in elective laparoscopic cholecystectomy.

BACKGROUND: The effects of varying levels of pre-operative opioids on post-operative outcomes following elective laparoscopic cholecystectomy is largely unknown. METHODS: Patients who underwent elective laparoscopic cholecystectomy from 2012 to 2019 were reviewed and categorized by the number of outpatient opioid prescriptions received in the 90 days preceding surgery: none (Naïve), one (1 Rx), two (2 Rx), or three or more (Chronic). Operative time, hospital length of stay, and 30-day readmission rate were analyzed. RESULTS: Of the 11911 patients identified, 2958 (24.8%) used opioids pre-operatively. Among patients with an overnight admission, the Naïve, 1 Rx, and 2 Rx cohorts had a shorter length of stay compared to the Chronic cohort. The Naïve group had the lowest 30-day readmission rate (5.0%) followed by the 1 Rx (5.9%), 2 Rx and Chronic groups (9.1% and 8.7%, respectively) (p < 0.001). CONCLUSIONS: Prevalence of pre-operative opioid use is high and warrants surgeon assessment to minimize adverse post-operative outcomes.

Factors that Minimize Curative Resection for Gallbladder Adenocarcinoma: an Analysis of Clinical Decision-Making and Survival.

BACKGROUND: Gallbladder adenocarcinoma has a poor prognosis as it is often diagnosed incidentally, and patients have a high risk for residual and occult metastatic disease. Expert guidelines recommend definitive surgery for ≥T1b tumors; however, surgical management is inconsistent. This study evaluates the factors that affect the completion of radical resection with portal lymphadenectomy and its impact on survival. METHODS: A retrospective review of patients who underwent surgery for gallbladder cancer from 2008 to 2017 at an academic institution was performed. Patients were analyzed based on whether they underwent definitive surgical resection. Patient factors and clinical decision-making were analyzed; overall survival was compared using Kaplan-Meier analysis. RESULTS: Seventy-five patients with ≥T1b tumors were identified, of who 32 (42.7%) underwent definitive resection. Fifty-four (72%) patients had gallbladder cancer identified as an incidental diagnosis following laparoscopic cholecystectomy. Among patients who did not undergo definitive resection, the underlying factors were varied. Only 24 (55.8%) patients in the non-definitive resection group were seen by surgical oncology. Among patients who underwent re-operation for definitive resection, 12 (38.7%) were upstaged on final pathology. Of the 43 patients who did not undergo definitive resection, 4 (9.3%) had metastatic disease identified during attempted re-resection. Patients who underwent definitive resection had a significantly longer median overall survival compared to those who did not (4.3 v. 1.9 years, p = 0.02). CONCLUSIONS: Patients undergoing definitive resection have a significantly improved survival, including as part of a re-operative strategy. Universal referral to a surgical specialist is a modifiable factor resulting in increased definitive resection rates.

Clinical Significance of Postoperative Antibiotic Treatment for Positive Islet Cultures After Total Pancreatectomy With Islet Autotransplantation.

OBJECTIVES: Islet cultures are routinely performed in total pancreatectomy with islet autotransplantation (TPIAT), and the need for empiric antibiotic treatment based on culture results is unknown. We evaluated the effect of postoperative antibiotic treatment for positive islet cultures on clinical infection. METHODS: Seventy-nine patients undergoing TPIAT were reviewed. Prophylactic perioperative ceftriaxone and metronidazole were administered, and transplanted islet preparations included ciprofloxacin. Postoperative antibiotics were not routinely given for positive cultures unless a clinical infection was suspected. The primary end point was 30-day infectious complications. RESULTS: Fifty-one patients (65%) had a positive culture. Overall, 39 patients (87%) had organisms susceptible to our perioperative antibiotic regimen. There was no difference in the infectious complication rate between those with positive compared with negative cultures (16% vs 29%, P = 0.17). Patients with a positive culture had similar 30-day postoperative infectious complication rates whether receiving postoperative antibiotics (n = 7) or not (14% vs 16%, P = 0.91). Only 1 patient had a correlation of clinical and islet cultures. CONCLUSIONS: Beyond prophylactic antibiotics, empiric antibiotic treatment for a positive culture is not warranted and provides a rationale for the abandonment of routine cultures in TPIAT.

Radiographic feasibility study of cortical bone trajectory and traditional pedicle screw dual trajectories.

OBJECTIVE In 2009, Santoni and colleagues described a novel technique of posterior instrumentation; the cortical bone trajectory (CBT) was described as a caudocephalad and medial-to-lateral trajectory. Reported indications for CBT fixation include patients with osteoporosis, single-level degenerative disease, or adjacent-segment disease (ASD). In cases of revision surgery, it is technically possible and beneficial to place a traditional pedicle screw and a CBT screw at the same spinal level and side. It remains unclear as to the feasibility of placing both a traditional and a CBT screw at all levels of the lumbar spine and with varying trajectories of the preexisting traditional pedicle screws. Therefore, the authors conducted a study to radiographically assess the feasibility of using CBT and traditional pedicle screws at the same level in a large patient population. METHODS Using a 3D Spine Navigation WorkStation, the authors assessed 47 lumbar spine CT scans. These images were obtained from 2 disparate groups of patients: those who had previously undergone traditional pedicle instrumentation (prior surgery group) and those who had not (no prior surgery group). The authors virtually placed traditional pedicle and CBT screws at each lumbar level bilaterally. It was then determined if the dual trajectories were feasible, as defined by the presence or absence of a collision of the screw trajectories based on 3D imaging. RESULTS Overall, the authors evaluated 47 patients and were able to successfully plan dual trajectories in 50% of the pedicles. The no prior surgery group, compared with the prior surgery group, had a significantly greater success rate for dual trajectories. This difference was most significant in the lower lumbar levels (L3-5) where the prior instrumented group had success rates lower than 40% compared with the no prior surgery group's success rate, which was greater than 70%. There was a significant difference between each lumbar level in the lower spine. CONCLUSIONS There is a significant difference in the feasibility of planning CBT screws in patients who have undergone prior pedicle instrumentation compared with placing CBT and traditional pedicle screws simultaneously, but dual trajectory pedicle screws are a feasible option for posterior lumbar spinal instrumentation, especially as a de novo option in osteoporotic patients or in patients with ASD who underwent previous pedicle instrumentation. Ultimately, the practical clinical utility and biomechanical effects on the spine and instrumentation construct would require additional study.