Uncoupling of Natural Killer cell functional maturation and cytolytic function in NOD mice

NK cells are innate immune cells that target infected and tumor cells. Mature NK (mNK) cells undergo functional maturation characterized by four distinct stages, during which they acquire their cytotoxic properties. mNK cells from non-obese diabetic (NOD) mice exhibit a defect in functional maturation and have impaired cytotoxic functions. Hence, we tested whether the impaired cytotoxic function observed in mNK cells from NOD mice can be explained by their defect in functional maturation. By comparing the function of mNK cells from B6, B6g7 and NOD mice, we show that the expression of granzyme B is severely impaired in mNK cells from NOD mice, agreeing with their inability to control tumor growth in vivo. The low level of granzyme B expression in mNK cells from NOD mice is found at all stages of functional maturation and is therefore independent of their functional maturation defect. Consequently, this study demonstrates that phenotypic functional maturation of mNK cells can be uncoupled from the acquisition of cytotoxic functions.

Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) for peritoneal mesothelioma: Canadian practices and outcomes

INTRODUCTION

Peritoneal mesothelioma (PM) is a rare malignancy originating from the peritoneal lining. Cytoreductive surgery (CRS) and heated intraperitoneal chemotherapy (HIPEC) is the standard-of-care for patients with isolated PM. Due to a paucity of prospective data there are several different HIPEC protocols. The aims of this study are to describe the CRS and HIPEC protocols for PM and patient outcomes across Canada.

METHODS

A multicenter retrospective study was performed on patients diagnosed and treated for PM with CRS and HIPEC in four major peritoneal disease centers in Canada between 2000 and 2021. Data on patient characteristics, treatment patterns, postoperative morbidity, recurrence, and survival were collected.

RESULTS

A total of 72 patients were identified. Mean age was 52 years (17-75) and 37.5% were male. Epithelioid (70.1%) and multicystic (13%) mesothelioma were the most common subtypes. Twenty-one patients (30%) were treated with neoadjuvant chemotherapy. CRS and HIPEC was performed in 64 patients (91.4%). Of these, the mean PCI was 22 (2-39) and cisplatin+doxorubicin was the most common HIPEC regimen (n = 33, 51.6%). A semi-closed coliseum technique was used in 68.8% of HIPECs and the mean duration of surgery was 486 min (90-1052). Clavien-Dindo III or IV complications occurred in 12 patients (16.9%). With a median follow-up of 24 months (0.2-104.4), we found a 5-year overall survival of 61% and a 5-year recurrence-free survival of 35%.

CONCLUSION

CRS and HIPEC is a safe and effective treatment modality for well-selected patients with PM, with some achieving prolonged survival.

Safety and clinical efficacy of EUS-guided pelvic abscess drainage

Background and Objectives

EUS is a potential alternative for the drainage of abscesses. The aim of this study was to determine if EUS-guided pelvic abscess drainage is technically feasible, safe, and a valid option for abscess resolution.

Methods

We conducted a retrospective review from 2002 to 2020 at a single quaternary institution. EUS-guided pelvic abscess drainage via the transrectal route was performed in all patients with or without drain/stent placement. Technical and clinical success of EUS-guided pelvic abscess drainage was analyzed. Descriptive analyses and Fisher exact test were performed.

Results

Sixty consecutive patients were included in the study (53.5% male; mean age, 53.8 ± 17.9 years). Pelvic abscesses occurred mainly postoperatively (33 cases; 60.0%) and from complicated diverticulitis (14 cases; 23.3%). Mean diameter was 6.5 ± 2.4 cm (80% unilocular). Drainage was performed with EUS-guided stent placement (double-pigtail plastic or lumen-apposing metal) in 74.5% of cases and with aspiration alone for the remainder. Technical success occurred in 58 cases (97%). Of those with long-term follow-up after EUS-guided pelvic abscess drainage (n = 55; 91.7%), complete abscess resolution occurred in 72.7% of all cases. Recurrence occurred in 8 cases (14.5%) and persisted in 7 patients (12.5%), 7 of which were successfully retreated with EUS-guided pelvic abscess drainage. Accounting for these successful reinterventions, the overall rate of abscess resolution was 85.5%. Abscess resolution rate improved with drain placement (83%). Accounting for 7 repeat EUS-guided pelvic abscess drainages, overall abscess resolution improved. Two deaths occurred (3.4%) because of sepsis from failed source control in patients who had previously failed medical, radiological, and surgical treatment.

Conclusions

EUS-guided pelvic abscess drainage is technically feasible, safe, and an effective alternative to radiological or open surgical drainage. It also offers favorable clinical outcomes in different clinical situations.

When a Drain is the Culprit: An Unexpected Case of Small Bowel Obstruction with Biliary Peritonitis

Although postoperative abdominal drains are useful in therapeutic settings, their prophylactic role is debatable. We herein describe the case of a 30-year-old male who underwent bile duct resection with hepaticojejunostomy for cholangiocarcinoma. On postoperative day four, the patient developed biliary peritonitis. Explorative laparotomy revealed an obstruction of the afferent limb caused by an intestinal loop around a Jackson-Pratt (JP) drain. Removal of the drain resolved the obstruction which led to a significant improvement of the patient’s clinical state. To the best of our knowledge, this is the second report of a bowel obstruction from a surgical drain. When placing abdominal drains, surgeons must take into consideration their indication as well as possible related complications, including intestinal obstruction. 

Neuroendocrine carcinoma arising in a tailgut cyst

INTRODUCTION

A tailgut cyst, also called retrorectal cystic hamartoma, is a rare congenital lesion that forms most commonly in the retrorectal space. It is presumed to arise from remnants of early embryogenesis.

PRESENTATION OF CASE

The following report describes a unique case of a retrorectal cystic hamartoma in a 53 year-old French Canadian man with a history of low back pain. The tumour underwent malignant transformation into a well-differentiated neuroendocrine carcinoma three years after the beginning of symptoms.

DISCUSSION

This condition can be found at any age, but occurs especially among middle-aged women. Not only is it frequently misdiagnosed, but also several complications associated to the cyst have been reported such as infection and malignant transformation. This is why complete surgical excision of the tailgut cyst is currently recommended.