Linear versus volumetric CT analysis in predicting tension-free fascial closure in abdominal wall reconstruction

Computed tomography for evaluation of abdominal wall hernias-what is the value of the Valsalva maneuver?

PURPOSE

To investigate the differences in the visibility and size of abdominal wall hernias in computed tomography (CT) with and without Valsalva maneuver.

METHODS

This single-center retrospective study included consecutive patients who underwent abdominal CTs with Valsalva maneuver between January 2018 and January 2022. Inclusion criteria was availability of an additional non-Valsalva CT within 6 months. A combined reference standard including clinical and surgical findings was used. Two independent, blinded radiologists measured the hernia sac size and rated hernia visibility on CTs with and without Valsalva. Differences were tested with a Wilcoxon signed rank test and McNemar's test.

RESULTS

The final population included 95 patients (16 women; mean age 46 ± 11.6 years) with 205 hernias. Median hernia sac size on Valsalva CT was 31 mm compared with 24 mm on non-Valsalva CT (p < 0.001). In 73 and 82% of cases, the hernias were better visible on CT with Valsalva as compared to that without. 14 and 17% of hernias were only visible on the Valsalva CT. Hernia visibility on non-Valsalva CT varied according to subtype, with only 0 and 3% of umbilical hernias not being visible compared with 43% of femoral hernias.

CONCLUSIONS

Abdominal wall hernias are larger and better visible on Valsalva CT compared with non-Valsalva CT in a significant proportion of patients and some hernias are only visible on the Valsalva CT. Therefore, this method should be preferred for the evaluation of abdominal wall hernias.

Deep learning model utilizing clinical data alone outperforms image-based model for hernia recurrence following abdominal wall reconstruction with long-term follow up

BACKGROUND

Deep learning models (DLMs) using preoperative computed tomography (CT) imaging have shown promise in predicting outcomes following abdominal wall reconstruction (AWR), including component separation, wound complications, and pulmonary failure. This study aimed to apply these methods in predicting hernia recurrence and to evaluate if incorporating additional clinical data would improve the DLM's predictive ability.

METHODS

Patients were identified from a prospectively maintained single-institution database. Those who underwent AWR with available preoperative CTs were included, and those with < 18 months of follow up were excluded. Patients were separated into a training (80%) set and a testing (20%) set. A DLM was trained on the images only, and another DLM was trained on demographics only: age, sex, BMI, diabetes, and history of tobacco use. A mixed-value DLM incorporated data from both. The DLMs were evaluated by the area under the curve (AUC) in predicting recurrence.

RESULTS

The models evaluated data from 190 AWR patients with a 14.7% recurrence rate after an average follow up of more than 7 years (mean ± SD: 86 ± 39 months; median [Q1, Q3]: 85.4 [56.1, 113.1]). Patients had a mean age of 57.5 ± 12.3 years and were majority (65.8%) female with a BMI of 34.2 ± 7.9 kg/m2. There were 28.9% with diabetes and 16.8% with a history of tobacco use. The AUCs for the imaging DLM, clinical DLM, and combined DLM were 0.500, 0.667, and 0.604, respectively.

CONCLUSIONS

The clinical-only DLM outperformed both the image-only DLM and the mixed-value DLM in predicting recurrence. While all three models were poorly predictive of recurrence, the clinical-only DLM was the most predictive. These findings may indicate that imaging characteristics are not as useful for predicting recurrence as they have been for other AWR outcomes. Further research should focus on understanding the imaging characteristics that are identified by these DLMs and expanding the demographic information incorporated in the clinical-only DLM to further enhance the predictive ability of this model.

Computed tomography measurements to predict need for robotic transversus abdominis release: a single institution analysis

PURPOSE

The radiographic rectus width to hernia width ratio (RDR) has been shown to predict ability to close fascial defect without additional myofascial release in open Rives-Stoppa abdominal wall reconstruction (AWR), but it has not been studied in robotic AWR. We aimed to examine various CT measurements to determine their usability in predicting the need for transversus abdominis release (TAR) in robotic AWR.

METHODS

We performed a single-center retrospective review of 137 patients with midline ventral hernias over a 5-year period who underwent elective robotic retrorectus AWR. We excluded patients with M1 or M5 hernias, lateral/flank hernias, and hybrid repairs. The CT measurements included hernia width (HW), hernia width/abdominal width ratio (HW/AW), and RDR. Univariate, multivariate and area under the curve (AUC) analyses were performed.

RESULTS

58/137 patients required TAR (32 unilateral, 26 bilateral). Patients undergoing TAR had a significantly higher average HW and HW/AW and lower RDR. Multivariate analysis revealed that prior hernia repair was independently associated with need for TAR (p = 0.03). ROC analysis and AUC values showed acceptable diagnostic ability of HW, HW/AW and RDR in predicting need for TAR. Cutoffs of RDR ≤ 2, HW/AW > 0.3, and HW > 10 cm yielded high specificity in determining need for any TAR (97.5% vs. 96.2% vs. 92.4%) or bilateral TAR (95.5% vs. 94.6% vs. 92.8%).

CONCLUSION

History of prior hernia repair was a risk factor for robotic TAR. CT measurements have some predictive value in determining need for TAR in robotic AWR. Further prospective analysis is needed in this patient population.

Intracystic injection of large surface area microparticle paclitaxel for chemoablation of intraductal papillary mucinous neoplasms: Insights from an expanded access protocol

AIMS

A novel large surface area microparticle paclitaxel (LSAM-PTX) has unique properties of long retention in cystic spaces while maintaining high drug concentration. We prospectively evaluated the safety and response of EUS-guided fine needle injection (EUS-FNI) of LSAM-PTX to chemoablate branch duct (BD)-IPMNs.

METHODS

Subjects diagnosed with BD-IPMNs exhibiting at least one worrisome criteria and considered non-surgical were enrolled in a multicenter clinical trial (NCT03188991) and subsequently included in an Expanded Access Protocol (EAP) where they received EUS-FNI of LSAM-PTX (15 mg/mL).

RESULTS

Six BD-IPMNs measuring (mean ± SD) 3.18 ± 0.76 cm in diameter among 5 subjects (mean age: 66 years) were treated by EUS-FNI of LSAM-PTX. A mean of 4 doses of LSAM-PTX (mean dose/cyst: 73 ± 31 mg) were administered, and subjects were followed for up to 32 months. The mean volume reduction/cyst ranged from 42 to 89% (9.58 ± 5.1 ml to 2.2 ± 1.1 ml (p = 0.016)). The mean surface area reduction ranged from 31 to 83% (21.9 ± 8.7 cm2 to 5.7 ± 2.5 cm2 (p = 0.009)). Higher dosing-frequency of EUS-FNI of LSAM-PTX significantly correlated with a reduction in cyst volume (R2 = 0.87, p = 0.03) and surface area (R2 = 0.83, p = 0.04). Comparing pre- and post-ablation samples, molecular analysis of the cyst fluid revealed a loss of IPMN-associated mutations in 5 cases (83.3%), while reemergence was observed in 1 case and persistence in 1 case. Intracystic changes (fibrosis/calcification) were observed in 83.3% (n = 5). One subject developed mild acute pancreatitis (1 of 22 EUS-FNIs of LSAM-PTX).

CONCLUSION

In this EAP, EUS-FNI of LSAM-PTX into BD-IPMNs was safe and resulted in volume and surface area reduction, morphological changes, and loss of pathogenic mutations.

Forecasting The Impact of the 2023 Current Procedural Terminology Coding Changes On Ventral Hernia Work Relative Value Units. A Cross-Sectional Study

BACKGROUND

In January 2023, significant changes were implemented to ventral hernia repair Current Procedural Terminology codes, with new codes replacing previous codes. The new codes were assigned a 0-day global period. The impact of these changes on clinical productivity remains unclear. Our objective was to forecast the impact of Current Procedural Terminology changes on ventral hernia-related work relative value units using historical data.

METHODS

Ventral hernia repairs performed between March 2021 and December 2022 on adults by a single surgeon with available 90-day follow-up were retrospectively retrieved from the Abdominal Core Health Quality Collaborative. Demographic, hernia, and operative and postoperative data were collected. The ventral hernia repairs were coded twice using the previous and new Current Procedural Terminology codes, and work relative value units were calculated using both systems. The median work relative value units per case were compared using the Wilcoxon signed-rank test.

RESULTS

A total of 143 ventral hernia repairs were included. The median age was 59 years, and 50% of patients were male. Median hernia width and length were 3.5 and 5.0 cm, respectively. The most common ventral hernia types were incisional 57% and umbilical 33%. Twenty percent of hernias were recurrent, and 99% were elective repairs. 49% of the procedures were open, 30% robotic, and 21% laparoscopic. Component separation was performed in 16%. The median length of stay was 0.0, and the median number of 90-day outpatient postoperative visits was 1.0. The new Current Procedural Terminology coding system was associated with a higher median 90-day work relative value units per case (14.1) than the previous system (13.8) (P = .002). Subset analysis identified statistically higher median 90-day work relative value units per case using the new versus previous Current Procedural Terminology codes for hernias with the largest defect dimension >10 cm (23.3 vs 18.8), umbilical/epigastric/Spigelian hernias (9.2 vs 7.1), recurrent hernias (20.1 vs 17.3) and open ventral hernia repairs (9.8 vs 7.1), all P < .05. Median 90-day work relative value units per case were statistically lower using the new versus previous codes for non-recurrent (11.6 vs 13.8) and incarcerated/strangulated (14.8 vs 14.9) hernias, all P < .05. In the new coding system, postoperative care within 90-days contributed to a median of 1.3 work relative value units per case (9% of total 90-day work relative value units).

CONCLUSION

We forecast that in our practice, the 2023 ventral hernia repair Current Procedural Terminology changes will result in a modest impact on clinical productivity. The impact of these changes on a particular practice depends on surgical practice patterns and ventral hernia case mix.

Measurements of abdominal wall defect and hernia sac volume for the treatment of incisional hernia: Application of the ultrasonic volume auto-scan in 50 cases

PURPOSE

Abdominal incisional hernia is one of the most common complications after surgery. The preoperative evaluation of the area of abdominal wall defect and the hernia sac volume(HCV) is very important for the selection of patch size and incisional herniorrhaphy. Meanwhile the overlap range of reinforcement repair is controversial. This study aimed to explore the value of ultrasonic volume auto-scan(UVAS) in the diagnosis, classification and treatment of incisional hernia.

METHODS

Both the width and the area of abdominal wall defect and HCV were measured by UVAS in 50 cases with incisional hernias. In 32 of these cases, the measurements of HCV were compared with those of CT. Classification of incisional hernia based on ultrasonic images were compared with operative diagnosis.

RESULTS

The measurements of HCV by UVAS and CT 3D reconstruction had good consistency, of which the mean ratio was 1.0084. According to the location and width of abdominal wall defect, UVAS, which showed good accuracy rate (90%, 96%), reached a good agreement in the classification of incisional hernias with operative diagnoses (Kappa = 0.85, Confidence Interval [0.718,0.996]; Kappa = 0.95, Confidence Interval [0.887,0.999]). The patch area should be at least two times as large as the defect area.

CONCLUSIONS

UVAS is an accurate alternative to measure the abdominal wall defect and HCV and classify the incisional hernia, with additional benefits of no radiation exposure and instant bedside interpretation. The use of UVAS is conducive to preoperative assessment of the risk of hernia recurrence and abdominal compartment syndrome.

Prediction models in hernia repair: a systematic review

BACKGROUND

Hernias can present with unique challenges when it comes to management and repair. Prediction models can be a useful tool for clinicians to better anticipate and understand the severity of a hernia, the type of surgical technique, or presurgical planning that may be required to treat the patient, and the risk of complications. Our goal is to evaluate and consolidate prediction models in hernia repair present in the literature for which physicians can reference to best improve patient outcomes and postoperative management.

METHODS

We performed a literature search in PubMed using keywords, "rectus width to defect width ratio," "predicting myofascial release," "computed tomography hernia repair prediction," "component separation radiology prediction hernia," "fat volume and hernia repair," "body morphometrics and Query hernia repair," "body morphometrics and reherniation," "computed tomography findings and risk of emergency hernia repair," "loss of domain and hernia radiology," and "volumetry and hernia repair." We searched for publications that used radiographic parameters to predict hernia severity, interventions, and outcomes.

RESULTS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we found twenty-three studies related to prediction models in hernia repair published between 2000 and 2021. We summarized studies pertaining to predicting acute care, predicting operative planning with loss of domain and component separation, predicting complications, paraesophageal hernia predictions, and predicting postoperative respiratory complications.

CONCLUSION

Radiographic prediction models can be an objective and efficient way for surgeons to analyze hernias and better understand a patient's situation so that they can inform patients about the best treatment options and the risk of complications.

A simplified method to evaluate the loss of domain

PURPOSE

The treatment of giant incisional hernia (IH) with loss of domain (LOD, IHLD) is considerably challenging due to technical difficulties and subsequent post-operative complications. These post-operative risks may be anticipated by calculating the abdominal cavity (AC) volume (ACV) and the IH volume (IHV) on the preoperative CT-scans, using the AC and IH dimensions (Tanaka's method) or using tridimensional volumetry (Sabbagh's method). These techniques are often time-consuming and require specific softwares. The aim of the present study was to develop a simple method to rapidly obtain the LOD-ratio on the preoperative CT-Scan.

METHODS

The CT-scans (n = 89) of patients with IHLD were retrospectively studied. Several ratios were calculated using different parameters of the AC and the IH, including width, height and depth, the areas (axial and sagittal ellipse, as well as freehand sagittal surface areas) and these were compared with the reference methods of Sabbagh et al. and Tanaka et al. RESULTS: The LOD ratios calculated from the two reference methods gave similar results (ICC = 0.82, p < 0.0001). The new "R-ratios" (Reims-ratios) obtained from the IH and AC surface areas measured using the "freehand ROI" tool on sagittal view or roughly evaluated by an ellipse on axial view showed excellent correlation with both reference ratios (all ICC ≥ 0.71, p < 0.0001).

CONCLUSION

The LOD ratio may be quickly obtained by drawing two circles on the pre-operative CT scan ("R ratios") and available on the webpage https://romeo.univ-reims.fr/Rratio/ . This will certainly help surgeons to routinely anticipate the post-operative complications before IHLD repair.

Reading a preoperative CT scan to guide complex abdominal wall reconstructive surgery

Computed tomography (CT) scanning is the imaging modality of choice when planning the overall management and operative approach to complex abdominal wall hernias. Despite its availability and well-recognised benefits there are no guidelines or recommendations regarding how best to read or report such scans for this application. In this paper we aim to outline an approach to interpreting preoperative CT scans in abdominal wall reconstruction (AWR). This approach breaks up the interpretive process into 4 steps-concentrating on the hernia or hernias, any complicating features of the hernia(s), the surrounding soft tissues and the abdominopelvic cavity as a whole-and was developed as a distillation of the authors' collective experience. We describe the key features that should be looked for at each of the four steps and the rationale for their inclusion.

Validation of a simple technique of volumetric analysis of complex incisional hernias without 3D CT scan reconstruction

PURPOSE

Volumetric analysis is being increasingly utilized in the preoperative evaluation of complex incisional hernias. Three-dimensional (3D) reconstruction of abdominal computed tomography (CT) scan has been used to obtain surface area (SA) and volume (Vol.) measurements, while others have used simple mathematical formulas to obtain SA and Vol. estimates without 3D reconstruction. Our objective was to assess the correlation of SA and Vol. measurements and estimates of complex incisional hernias.

METHODS

We conducted a retrospective agreement study of adults who underwent abdominal wall reconstruction from 2007 to 2018. Demographics, hernia characteristics, and operative data were collected from the medical record. SA and Vol. measurements were obtained after 3D CT reconstruction. Linear CT variables were obtained independently by two surgeons and SA and Vol. estimates were calculated. Because both surgeons reported similar results, only lead author values are reported in the abstract. We used Pearson's correlation coefficient (r) to assess inter-rater agreement and the agreement between SA and Vol. measurements and estimates.

RESULTS

A total of 108 patients were eligible for analysis. The mean age was 57 ± 11 years and 53 (49%) were female. 42 (39%) hernias were recurrent, 10 (9%) patients had a stoma, and 9 (8%) had a history of open abdomen. The mean defect width was 11 ± 4 cm and mean defect surface area (DSA) was 150 ± 95 cm². Inter-rater agreement of SA and Vol. estimates was high (r ≥ 0.80). There was high correlation between SA and Vol. measurements and estimates for DSA, hernia sac volume (HSV), abdominal cavity volume (ACV), and HSV/ACV ratio (r = 0.81, 0.89, 0.94 and 0.91, respectively).

CONCLUSION

SA and Vol. estimates demonstrated high level of agreement with SA and Vol. measurements using 3D reconstruction. SA and Vol. estimates can be obtained using simple mathematical formulas using easily obtained linear variables negating the need for the time and effort consuming 3D reconstruction.