Posterior Approach for Laparoscopic Pancreaticoduodenectomy to Prevent Replaced Hepatic Artery Injury

Background

Laparoscopic pancreaticoduodenectomy (PD) has become more popular despite its complexity and tendency for higher morbidity.1 Replaced right hepatic artery (RRHA) and replaced common hepatic artery (RCHA), both originating from the superior mesenteric artery (SMA), are the most significant and relatively common vascular anomalies in patients undergoing PD, occurring in 8.6–21 and 0.4–4.5 % of cases, respectively.2 ^, 3 An inadvertent injury to theses arteries may result in an intra- or postoperative bleeding, hepatic or bile duct ischemia, and consequent leakage or delayed stricture in the bilioenteric anastomosis.2 ^– 4 Therefore, preservation of these aberrant hepatic arteries is essential unless their resection is oncologically indicated.2 We describe a posterior approach that can be advantageous in laparoscopic PD for patients with a RRHA or RCHA.

Methods

The posterior approach was used in 81 laparoscopic PDs at the Institute Mutualiste Montsouris between 1994 and 2012.5 In brief, retropancreatic dissection is performed to complete kocherization and expose the posterolateral aspect of the SMA. The origin of the RRHA or RCHA can then be identified and dissected. After division of the pancreatic neck, the portal vein and RRHA or RCHA are separated off the pancreatic neck. In case of the RCHA, the gastroduodenal artery originating from the RCHA is divided during this dissection.

Results

The video shows a secure procedure to preserve a RCHA in laparoscopic PD by early identification and dissection of the aberrant artery via the posterior approach.

Conclusions

The posterior approach can help to prevent inadvertent RRHA or RCHA injury in laparoscopic PD.     

“The Lister Technique”: a new technique for the management of the distal ureter during radical robotic nephroureterectomy

We describe “The Lister Technique”—a new 3 step procedure developed in our department for robotic assisted laparoscopic nephroureterectomy (RANU). Our new technique facilitates the complete excision of the whole ureter including ureteric orifice and reduces this risk of tumour spillage from the distal ureter without the need for bivalving the bladder. Our initial data indicates that the technique is associated with reduction in bladder recurrence post-operatively in comparison to current published series. Longer follow up and larger patient numbers are required to validate these results further.     

First in-Human Gallbladder Cryoablation in a Patient with Acute Calculous Cholecystitis Initially Treated with a Cholecystostomy Tube

A 71-year-old poor surgical candidate with acute calculous cholecystitis was initially managed with cholecystostomy tube drainage for 28 days. He subsequently underwent gallbladder cryoablation under moderate sedation with 3 cryoprobes and 2 separate 10-8-10 freeze-thaw cycles targeting the gallbladder neck/body and fundus followed by cholecystostomy tube removal. He was discharged 1 day after ablation. Magnetic resonance and hepatobiliary iminodiacetic acid scan 1 month postablation demonstrated a thick-walled, distended gallbladder and no filling of the cystic duct. Magnetic resonance 3 months postablation demonstrated retraction of the gallbladder wall with luminal collapse. The patient denied any pain after discharge and is asymptomatic 3 months after ablation.     

Eradication of Missing Liver Metastases After Fiducial Placement

Background

The risk of colorectal liver metastases (CLM) disappearing on cross-sectional imaging has increased with advances in preoperative chemotherapy, but <50 % of disappearing CLM demonstrate complete pathological response.

Objective

The aim of this study was to evaluate the role of fiducial marker placement before potentially curative treatment of CLM at risk of disappearing with chemotherapy.

Methods

All consecutive patients who underwent fiducial placement for tracking of CLM at a tertiary center were reviewed.

Results

Among 1377 patients undergoing CLM resection between 2005 and 2015, 35 patients underwent fiducial placement. Three patients were excluded due to disease progression. The study population comprised 32 patients who underwent fiducial placement in 41 CLM. Among the 41 marked CLM, 34 (83 %) were located >10 mm deep in the liver parenchyma, 25 (61 %) were in the right liver, and median size was 12 mm (range, 6–20 mm). No complication occurred after fiducial placement. After chemotherapy, 19 (46 %) of the 41 marked metastases disappeared on cross-sectional imaging. All fiducial-tracked CLM were treated with resection (n?=?31) or ablation (n?=?10). After median follow-up of 14 months (range, 0–64 months), no local recurrences were observed.

Conclusion

Fiducial placement represents a safe procedure that facilitates accurate localization for resection or ablation of small CLM at risk of disappearing with chemotherapy.

     

Chronic exposure to Helicobacter pylori impairs dendritic cell function and inhibits Th1 development

Helicobacter pylori causes chronic gastric infection that affects the majority of the world's population. Despite generating an inflammatory response, the immune system usually fails to clear the infection. Since dendritic cells (DCs) play a pivotal role in shaping the immune response, we investigated the effects of H. pylori on DC function. We have demonstrated that H. pylori increased the expression of activation markers on DCs while upregulating the inhibitory B7 family molecule, PD-L1. Functionally, H. pylori-treated DCs resulted in the production of interleukin-10 (IL-10) and IL-23 but not of alpha interferon (IFN-alpha). While very little or no IL-12 was produced to H. pylori alone, simultaneous ligation of CD40 on DCs induced IL-12 release. We also demonstrated that DCs treated with H. pylori-induced IFN-gamma production by allogeneic naive T cells. However, stimulation of DCs with H. pylori for an extended period of time impaired their ability to produce cytokines after CD40 ligation and limited their ability to promote IFN-gamma release, suggesting that the DCs had become exhausted by the prolonged stimulation. The effect of chronic infection with H. pylori on DC function was further investigated by focusing on DC development. Demonstrating that monocytes differentiated into DCs in the presence of H. pylori exhibited an exhausted phenotype with an impaired ability to produce IL-12 and a downregulation of CD1a. Our results raise the possibility that in chronic H. pylori infection DCs become exhausted after prolonged antigen exposure leading to suboptimal Th1 development. This effect may contribute to persistence of H. pylori infection.     

Reduced pathology following infection with transgenic Leishmania major expressing murine CD40 ligand

Leishmanization is the inoculation of live Leishmania into the host to vaccinate against subsequent infections. This approach has been largely discontinued due to safety concerns. We have previously shown that combining CD40 ligand (CD40L) with Leishmania antigen preferentially induces a type 1 immune response and provides some protection to vaccinated mice (G. Chen, P. A. Darrah, and D. M. Mosser, Infect. Immun. 69:3255-3263, 2001). In the present study, we developed transgenic L. major organisms which express and secrete the extracellular portion of CD40L (L. major CD40LE). We hypothesized that these organisms would be less virulent but more immunogenic than wild-type organisms and therefore be more effective at leishmanization. Transgenic parasites expressing CD40L mRNA and protein were developed. BALB/c mice infected with these parasites developed significantly smaller lesions containing fewer parasites than animals infected with wild-type organisms. Infection of resistant C57BL/6 mice with low doses of transgenic parasites induced a significant amount of protection against subsequent high-dose infection with wild-type organisms. These results demonstrate that transgenic organisms expressing CD40L are less virulent than wild-type organisms while retaining full immunogenicity.