Critical appraisal of surgical margins according to KRAS status in liver resection for colorectal liver metastases: Should surgical strategy be influenced by tumor biology?

BACKGROUND

KRAS mutation is a negative prognostic factor for colorectal liver metastases. Several studies have investigated the resection margins according to KRAS status, with conflicting results. The aim of the study was to assess the oncologic outcomes of R0 and R1 resections for colorectal liver metastases according to KRAS status.

METHODS

All patients who underwent resection for colorectal liver metastases between 2010 and 2015 with available KRAS status were enrolled in this multicentric international cohort study. Logistic regression models were used to investigate the outcomes of R0 and R1 colorectal liver metastases resections according to KRAS status: wild type versus mutated. The primary outcomes were overall survival and disease-free survival.

RESULTS

The analysis included 593 patients. KRAS mutation was associated with shorter overall survival (40 vs 60 months; P = .0012) and disease-free survival (15 vs 21 months; P = .003). In KRAS-mutated tumors, the resection margin did not influence oncologic outcomes. In multivariable analysis, the only predictor of disease-free survival and overall survival was primary tumor location (P = .03 and P = .03, respectively). In KRAS wild-type tumors, R0 resection was associated with prolonged overall survival (74 vs 45 months, P < .001) and disease-free survival (30 vs 17 months, P < .001). The multivariable model confirmed that R0 resection margin was associated with prolonged overall survival (hazard ratio = 1.43, 95% confidence interval: 1.01-2.03) and disease-free survival (hazard ratio = 1.42; 95% confidence interval: 1.06-1.91).

CONCLUSIONS

KRAS-mutated colorectal liver metastases showed more aggressive tumor biology with inferior overall survival and disease-free survival after liver resection. Although R0 resection was not associated with improved oncologic outcomes in the KRAS-mutated tumors group, it seems to be of paramount importance for achieving prolonged long-term survival in KRAS wild-type tumors.

Long-Term Outcomes of Perioperative Versus Neoadjuvant Chemotherapy for Resectable Colorectal Liver Metastases: An International Multicentre Propensity-Score Matched Analysis with Stratification by Contemporary Risk-Scoring

BACKGROUND

There is still debate regarding the principal role and ideal timing of perioperative chemotherapy (CTx) for patients with upfront resectable colorectal liver metastases (CRLM). This study assesses long-term oncological outcomes in patients receiving neoadjuvant CTx only versus those receiving neoadjuvant combined with adjuvant therapy (perioperative CTx).

METHODS

International multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010 and 2015. Characteristics and outcomes were compared before and after propensity score matching (PSM). Primary endpoints were long-term oncological outcomes, such as recurrence-free survival (RFS) and overall survival (OS). Furthermore, stratification by the tumour burden score (TBS) was applied.

RESULTS

Of 967 patients undergoing hepatectomy, 252 were analysed, with a median follow-up of 45 months. The unmatched comparison revealed a bias towards patients with neoadjuvant CTx presenting with more high-risk patients (p = 0.045) and experiencing increased postoperative complications ≥Clavien-Dindo III (20.9% vs. 8%, p = 0.003). Multivariable analysis showed that perioperative CTx was associated with significantly improved RFS (hazard ratio [HR] 0.579, 95% confidence interval [CI] 0.420-0.800, p = 0.001) and OS (HR 0.579, 95% CI 0.403-0.834, p = 0.003). After PSM (n = 180 patients), the two groups were comparable regarding baseline characteristics. The perioperative CTx group presented with a significantly prolonged RFS (HR 0.53, 95% CI 0.37-0.76, p = 0.007) and OS (HR 0.58, 95% CI 0.38-0.87, p = 0.010) in both low and high TBS patients.

CONCLUSIONS

When patients after resection of CRLM are able to tolerate additional postoperative CTx, a perioperative strategy demonstrates increased RFS and OS in comparison with neoadjuvant CTx only in both low and high-risk situations.

Liver resection in elderly patients with extensive CRLM: Are we offering an adequate treatment? A propensity score matched analysis

BACKGROUND

Data on the management of elderly patients with extensive colorectal liver metastases (CRLM) are scarce and conflicting. This study assesses differences in management and long-term oncological outcomes between older and younger patients with CRLM and a high Tumour Burden Score (TBS).

METHODS

International multicentre retrospective study on patients with CRLM and a category 3 TBS, submitted to liver resection. Patients were divided into two groups according to their age (younger and older than 75) and were compared using propensity score matching (PSM) analysis and multivariable regression models. Differences in management and oncological outcomes including recurrence-free survival (RFS) and overall survival (OS) were assessed.

RESULTS

The study included 386 patients, median follow-up was 48 months. The unmatched comparison revealed a higher ASA score (p = 0.035), less synchronous CRLM (47% vs 68%, p = 0.003), a lower median number of lesions (1 vs 3, p = 0.004) and less perioperative chemotherapy (CTx) (66% vs 88%, p < 0.001) in the elderly group. Despite the absence of CTx being an independent predictor of decreased RFS and OS (HR 0.760, p = 0.044 and HR 0.719, p = 0.049, respectively), the elderly group still received less CTx (OR 0.317, p = 0.001) than the younger group. After PSM (n = 100 patients), the two groups were comparable, however, CTx administration was still significantly lower in the elderly group.

CONCLUSION

Liver resection should be considered in patients aged 75 and older, even if they present with extensive liver disease. Despite CTx being associated with improved oncological outcomes, a large percentage of elderly patients with CRLM are undertreated.

Perioperative chemotherapy versus surgery alone for resectable colorectal liver metastases: an international multicentre propensity score matched analysis on long-term outcomes according to established prognostic risk scores

BACKGROUND

There is still uncertainty regarding the role of perioperative chemotherapy (CTx) in patients with resectable colorectal liver metastases (CRLM), especially in those with a low-risk of recurrence.

METHODS

Multicentre retrospective analysis of patients with CRLM undergoing liver resection between 2010-2015. Patients were divided into two groups according to whether they received perioperative CTx or not and were compared using propensity score matching (PSM) analysis. Then, they were stratified according to prognostic risk scores, including: Clinical Risk Score (CRS), Tumour Burden Score (TBS) and Genetic And Morphological Evaluation (GAME) score.

RESULTS

The study included 967 patients with a median follow-up of 68 months. After PSM analysis, patients with perioperative CTx presented prolonged overall survival (OS) in comparison with the surgery alone group (82.8 vs 52.5 months, p = 0.017). On multivariable analysis perioperative CTx was an independent predictor of increased OS (HR 0.705, 95%CI 0.705-0.516, p = 0.029). The benefits of perioperative CTx on survival were confirmed in patients with CRS and TBS scores ≤2 (p = 0.022 and p = 0.020, respectively) and in patients with a GAME score ≤1 (p = 0.006).

CONCLUSION

Perioperative CTx demonstrated an increase in OS in patients with CRLM. Patients with a low-risk of recurrence seem to benefit from systemic treatment.

Penetrating cardiac injuries: predictive model for outcomes based on 2016 patients from the National Trauma Data Bank

BACKGROUND

Penetrating cardiac injuries are uncommon and lethal. The objectives of this study are to examine the national profile of cardiac injuries, identify independent predictors of outcome, generate, compare and validate previous predictive models for outcomes. We hypothesized that National Trauma Data Bank (NTDB) given its large number of patients, would validate these models.

METHODS

The NTDB was queried for data on cardiac injuries, using survival as the main outcome measure. Statistical analysis was performed utilizing univariate and stepwise logistic regression. The stepwise logistic regression model was then compared with other predictive models of outcome.

RESULTS

There were 2016 patients with penetrating cardiac injuries identified from 1,310,720 patients. Incidence: 0.16%. Mechanism of injury: GSWs-1264 (63%), SWs-716 (36%), Shotgun/impalement-19/16 (1%). Mean RTS 1.75, mean ISS 27 ± 23. Overall survival 675 (33%). 830 patients (41%) underwent ED thoracotomy, 47 survived (6%). Survival stratified by mechanism: GSWs 114/1264 (10%), SWs 564/717 (76%). Predictors of outcome for mortality-univariate analysis: vital signs, RTS, ISS, GCS: Field CPR, ED intubation, ED thoracotomy and aortic cross-clamping (p < 0.001). Stepwise logistic regression identified cardiac GSW's (p < 0.001; AOR 26.85; 95% CI 17.21-41.89), field CPR (p = 0.003; AOR 3.65; 95% CI 1.53-8.69), the absence of spontaneous ventilation (p = 0.008; AOR 1.08, 95% CI 1.02-1.14), the presence of an associated abdominal GSW (p = 0.009; AOR 2.58, 95% CI 1.26-5.26) need for ED airway (p = 0.0003 AOR 1386.30; 95% CI 126.0-15251.71) and aortic cross-clamping (p = 0.0003 AOR 0.18; 95% CI 0.11-0.28) as independent predictors for mortality. Overall predictive power of model-93%.

CONCLUSION

Predictors of outcome were identified. Overall survival rates are lower than prospective studies report. Predictive model from NTDB generated larger number of strong independent predictors of outcomes, correlated and validated previous predictive models.

Predictors of outcome in 101 patients requiring emergent thoracotomy for penetrating pulmonary injuries

BACKGROUND

Operative interventions are uncommonly required for penetrating pulmonary injuries. Similarly, because their incidence is low, few series appear sporadically in the literature. Objectives of this study are to identify predictors of outcome for patients requiring emergent thoracotomy for penetrating pulmonary injuries and evaluate the use of tissue sparing versus resective techniques for their management.

STUDY DESIGN

This is a retrospective 169-month study of all patients with penetrating pulmonary injuries requiring thoracotomy. The main outcome measures are: physiologic parameters, AAST-OIS injury grade, surgical procedures and mortality. Statistical analysis includes univariate and stepwise logistic regression.

RESULTS

101 patients required thoracotomy for penetrating pulmonary injuries. Mechanism of injury includes: gunshot wounds (GSW)-73 (72%), stab wounds (SW)-28 (33%). Mean systolic BP 97 ± 47, mean HR 92 ± 47, and mean admission pH 7.22 ± 0.17. Mean RTS 6.25 ± 2.7, mean ISS 36 ± 22. The mean estimated blood loss (EBL) was 5277 ± 4955 mls. Predictors of outcome are: admission pH (p = 0.0014), admission base deficit (p < 0.0001), packed red blood cells (PRBCs) transfused (p = 0.023), whole blood transfused (p < 0.01). A total of 143 procedures were required in 101 patients: tissue sparing 114 (80%) versus resective procedures 29 (20%). Only pneumonectomy (p = 0.024) predicted outcome. Overall survival 64/101-64%. American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) injury grades I-III versus IV-VI predicts survival (p < 0.001). Stepwise logistic regression identified AAST-OIS injury grades IV-VI (p = 0.007; OR 6.38 [95% CI 1.64-24.78]), intraoperative dysrhythmias (p = 0.003; OR 17.38 [95% CI 2.59-116.49]) and associated cardiac injuries (p = 0.02; OR 8.74 [95% CI 1.37-55.79]) as independent predictors of outcome.

CONCLUSIONS

Predictors of outcome for penetrating pulmonary injuries requiring thoracotomy are identified and must be taken into account in their operative management. Tissue sparing techniques-stapled pulmonary tractotomy is once again validated, and it remains effective as the mainstay for their management; however, only pneumonectomy predicts outcome. AAST-OIS injury grades IV-VI predict outcome with higher injury grades requiring resective procedures.

Femoral vessel injuries; high mortality and low morbidity injuries

Femoral vessel injuries are amongst the most common vascular injuries admited in busy trauma centers. The evolution of violence and the increase in penetrating trauma from the urban battlefields of city streets has raised the incidence of femoral vessel injuries, which account for approximately 70% of all peripheral vascular injuries. Despite the relatively low mortality associated with these injuries, there is a high level of technical complexity required for the performance of these repairs. Similarly, they incur low mortality but are associated with significantly high morbidity. Prompt diagnosis and treatment are the keys to successful outcomes with the main goals of managing ischemia time, restoring limb perfusion, accomplishing limb salvage and instituting rehabilitation as soon as possible.

Popliteal vessel injuries: complex anatomy, difficult problems and surgical challenges

The incidence of popliteal vessel injuries is low, even in busy urban trauma centers. As a result of this fact, few trauma centers and trauma surgeons have developed extensive experience in the management of these injuries. Popliteal vessel injuries in both civilian and military arenas incur significant morbidity. These injuries present a difficult challenge, and, although the overall incidence of these injuries remains low, the sequelae can be devastating. Successful outcomes for limb salvage and survival result from early recognition and rapid surgical intervention by a multidisciplinary approach with a great participation of different surgical specialties. From the historical perspective, anatomy, incidence and associated injuries, to the clinical presentation, diagnosis, management, and morbidity and mortality, the aim of this article is to review the various aspects of these complex injuries.

Shank vessel injuries: the forgotten vascular injuries

INTRODUCTION

Vascular injuries in branch vessels of the popliteal artery, such as the tibioperoneal trunk, and shank vessels, such as anterior, posterior tibial, and peroneal vessels, occur in both blunt and penetrating trauma. Their management has evolved significantly in the past few decades. While their incidence is variable, limb loss and morbidity remain significant.

MATERIAL AND METHODS

Physical examination, along with measuring an Ankle-Brachial Index (ABI), is still sometimes all that is required for diagnosis and can expeditiously triage those that require urgent operation. Despite our technological advancements and newer algorithms for lower extremity vascular trauma, operative intervention and exposure still remain difficult and pose a great challenge for surgeons that normally do not operate on this area.

CONCLUSIONS

Shank vessel injuries still comprise a significant proportion of combat and civilian vascular injuries, and modern advances have led to a dramatic decrease in amputation rates.

Iliac vessel injuries: difficult injuries and difficult management problems

INTRODUCTION

Injury to the iliac vessels poses a serious and frustrating treatment dilemma for all trauma surgeons. Generally, patients present in profound shock secondary to severe hemorrhage from either iliac arterial, venous, or combined injuries. Despite improvements in our emergency medical services (EMS), rapid transport, standard training of trauma surgeons, and improved technology, the morbidity and mortality from iliac vessel injuries remain high, ranging from 25 to 40 %.

MATERIALS AND METHODS

A systematic review of the literature, with emphasis placed on the diagnosis, treatment, and outcomes of these injuries, incorporating the author's experience.

CONCLUSIONS

Injuries to the iliac vessel remain a daunting task, even after great advances in anatomic injury grading and damage control as well as advances in surgical techniques and critical care. Despite all the advances in treatment and appropriate management strategies, the morbidity and mortality from iliac vessel injuries remain high, demonstrating the complex challenge their treatment presents to even the modern-day trauma surgeon.