伊藤 誉

BACKGROUND: The aim of this study was to evaluate the effect of staple height and rectal wall thickness on the development of an anastomotic leak after laparoscopic low anterior resection performed with the double stapling technique. METHODS: One hundred ninety-nine patients treated from 2013 to 2021 were enrolled. Patients were divided into two groups: those who developed an anastomotic leak (AL (+)) and those who did not (AL (-)). Clinicopathological factors were compared between the groups. RESULTS: Anastomotic leaks were observed in 8/199 patients (4%). A 1.5 mm linear stapler was used for 35/199 patients (17%), 1.8 mm for 89 (45%), and 2 mm for 75 (38%). In the AL (+) group (n = 8), lower staple height (1.5 mm or 1.8 mm) was used more frequently than in the AL (-) group (n = 191). Rectal wall thickness and the rectal wall thickness to staple height ratio was significantly (p < .05) greater in the AL (+) group. However, rectal wall thickness was significantly (p < .05) greater in patients who received neoadjuvant treatment and those with advanced T stage (T3,4) lesions. CONCLUSION: Linear stapler staple height and rectal wall thickness are significantly associated with the development of an anastomotic leak after laparoscopic low anterior resection. Larger staples should be selected in patients with a thicker rectal wall due to neoadjuvant treatment or adjacent advanced rectal tumors.

Adenocarcinoma in a Meckel's diverticulum is rare and difficult to diagnose preoperatively. We report the first case of a metachronous Krukenberg tumor from adenocarcinoma in a Meckel's diverticulum. A 45-year-old woman was admitted for recurrent abdominal pain. Computed tomography scan showed a lesion with contrast enhancement, and a Meckel's diverticulum-associated tumor was suspected. Double-ballon enteroscopy revealed intestinal stenosis and biopsy showed adenocarcinoma. Operative findings showed a Meckel's diverticulum with tumor. Histopathological evaluation revealed well-differentiated adenocarcinoma, interrupted by ectopic gastric mucosa, diagnosed as adenocarcinoma in a Meckel's diverticulum. Two years postoperatively, a multi-cystic mass with contrast enhancement was observed in the pelvis on imaging evaluation and oophorectomy performed. Histological examination of the resected ovary showed proliferation of atypical glandular ducts, consistent with metastatic adenocarcinoma. This case demonstrates that adenocarcinoma in a Meckel's diverticulum may result in distant metastases and requires appropriate follow-up.

Pyroptosis is a form of regulated cell death that is characterized by gasdermin processing and increased membrane permeability. Caspase-1 and caspase-11 have been considered to be essential for gasdermin D processing associated with inflammasome activation. In the present study, we found that NLRP3 inflammasome activation induces delayed necrotic cell death via ASC in caspase-1/11-deficient macrophages. Furthermore, ASC-mediated caspase-8 activation and subsequent gasdermin E processing are necessary for caspase-1-independent necrotic cell death. We define this necrotic cell death as incomplete pyroptosis because IL-1β release, a key feature of pyroptosis, is absent, whereas IL-1α release is induced. Notably, unprocessed pro-IL-1β forms a molecular complex to be retained inside pyroptotic cells. Moreover, incomplete pyroptosis accompanied by IL-1α release is observed under the pharmacological inhibition of caspase-1 with VX765. These findings suggest that caspase-1 inhibition during NLRP3 inflammasome activation modulates forms of cell death and permits the release of IL-1α from dying cells.

Long-term peritoneal dialysis (PD) therapy leads to peritoneal inflammation and fibrosis. However, the mechanism underlying PD-related peritoneal inflammation and fibrosis remains unclear. NLRP3 inflammasome regulates the caspase-1-dependent release of interleukin-1β and mediates inflammation in various diseases. Here, we investigated the role of NLRP3 inflammasome in a murine model of PD-related peritoneal fibrosis induced by methylglyoxal (MGO). Inflammasome-related proteins were upregulated in the peritoneum of MGO-treated mice. MGO induced parietal and visceral peritoneal fibrosis in wild-type mice, which was significantly reduced in mice deficient in NLRP3, ASC, and interleukin-1β (IL-1β). ASC deficiency reduced the expression of inflammatory cytokines and fibrotic factors, and the infiltration of macrophages. However, myeloid cell-specific ASC deficiency failed to inhibit MGO-induced peritoneal fibrosis. MGO caused hemorrhagic ascites, fibrin deposition, and plasminogen activator inhibitor-1 upregulation, but all of these manifestations were inhibited by ASC deficiency. Furthermore, in vitro experiments showed that MGO induced cell death via the generation of reactive oxygen species in vascular endothelial cells, which was inhibited by ASC deficiency. Our results showed that endothelial NLRP3 inflammasome contributes to PD-related peritoneal inflammation and fibrosis, and provide new insights into the mechanisms underlying the pathogenesis of this disorder.

クリニカルパスを用いて周術期管理を行った直腸癌前方切除症例94例を対象とし、以前のクリニカルパスで周術期管理を行った40例(男性21名、女性19名、65±10歳;5日目食事開始パス群)と経口摂取を早めたクリニカルパスで周術期管理を行った54例(男性33名、女性21名、61±12歳;2日目食事開始パス群)に分けた。手術に関しては、2日目食事開始パス群で腹腔鏡の手術の割合が増加した。入院中の経過は、術後在院日数は両群とも平均12日でパス通りであった。バリアンスでは2日目食事開始パス群において飲水や流動食開始遅延が有意に多く認められたが、退院が13日目以降に遅延した症例は2群間で有意差がなかった。ドレーン挿入留置期間も2群間で有意差を認めなかった。術後合併症は、SSIおよび縫合不全症例は2群間で有意差を認めなかった。一過性腸管麻痺を含めた術後イレウスが2日目食事開始パス群で有意に減少した。尿道カテーテル抜去後の尿閉の発症頻度は2日目食事開始パス群で少なかった。退院後の経過では2群とも再入院や再手術を要する症例は一例も認めなかった。

要旨：77 歳男性．急性A 型大動脈解離を認め，術前心タンポナーデに伴うショック状態であった．造影CT では，偽腔開存の大動脈解離を認め腹部分枝まで解離が及んでいた．緊急上行大動脈置換術を施行し，術中腸管虚血を疑う所見なく手術を終了した．術後10 時間で下血を認め緊急試験開腹手術を施行した．小腸に虚血を認めず，S 状結腸壊死を認め結腸切除を施行した．帰室後よりアシドーシスの進行と膀胱内圧軽度高値を認め，再度腸管虚血を疑い，2 回目の緊急試験開腹術を施行した．広範な小腸虚血を認めたが，切除範囲が広く切除を断念した．しかし保存的治療で腸管虚血・全身状態の改善を認め退院となった．可逆的な腸管虚血の診断は難しいが，広範な虚血のため虚血部腸管が切除できない症例でもその後虚血が回復することがあり，腸管虚血に対し試験開腹による腹腔内圧の減圧効果が治療に奏功した可能性がある．

35歳男。慢性的に腹痛が出現し、検診で便鮮血を指摘された。下部内視鏡検査を施行され、回腸末端に潰瘍性病変を指摘された。経肛門的ダブルバルーン内視鏡(DBE)を施行した。回盲弁は破壊され、回腸末端から5cm程の長さで、不整形の潰瘍を認めた。腹部造影CTでは、盲腸から回腸末端にかけて壁肥厚、造影効果を認め周囲脂肪織の索状影や濃度の上昇を認めた。回腸末端に深い潰瘍、狭窄を認め、腹痛も改善傾向ないため診断、治療目的に腹腔鏡下補助下回盲部切除術を行う方針とした。口腔内アフタ、ブドウ膜炎、外陰部潰瘍などの既往なく、Behcet病の診断基準を満たさないため単純性潰瘍と診断した。合併症の発症なく、術後9日目に退院となった。

Dilatation and curettage (D&C) sometimes causes uterine perforation, which usually does not cause a serious problem. Here, we report uterine perforation caused by D&C, in which the small intestine prolapsed from the uterus, requiring intestinal resection. D&C was performed for missed abortion at 9 weeks. After dilating the cervix, forceps grasped tissue that, upon being pulled, resulted in the intestine being prolapsed into the vagina. Laparotomy revealed a perforation at the low anterior uterine wall, through which the ileum had prolapsed. The mesentery of the prolapsed ileum was completely detached and the ileum was necrotic, which was resected. The uterus and the intestine were reconstructed. Although intestinal prolapse is considered to be caused by "unsafe" D&C performed by inexperienced persons or even by nonphysicians in developing countries, this occurred in a tertiary center of a developed country. We must be aware that adverse events such as uterine perforation with intestinal prolapse can occur even during routine D&C.

80歳代男。食欲不振を主訴とした。血液検査で閉塞性黄疸と肝胆道系酵素、腫瘍マーカーの上昇を認め、腹部造影CTでは胆嚢癌の胆嚢床浸潤による肝門部胆管・十二指腸球部・横行結腸への浸潤と、播種・リンパ節転移が疑われた。胆嚢癌Stage IVbの臨床診断で、入院5〜16日目に内視鏡的逆行性胆管膵管造影・下部消化管内視鏡・上部消化管内視鏡によりそれぞれ胆管・十二指腸および横行結腸の狭窄に対して3期的にstentを内挿し、入院19日目に経口摂取を開始した。黄疸・便秘は改善し、入院44日目に退院した。退院後4ヵ月経過してステントの狭窄は認めていない。

59歳男性。検診の上部消化管内視鏡検査にて食道異常所見を指摘され、著者らの施設へ受診となった。所見では上部消化管造影および胸部CT、MRI検査では胸部下部〜中部食道に粘膜下腫瘍が認められた。また、FDG-PETでは食道病変に一致して異常集積を示し、超音波内視鏡では腫瘍は低エコーを呈していた。以後、EUS-FNABの結果、本症例は食道GISTと診断され、リスク分類で中間リスク以上と考え、右開胸開腹中下部食道切除ならびに胸腔内胃管再建術が行われた。その結果、術後の経過は良好で、患者は第26病日目に軽快退院となった。

70歳代女。40年前に胃潰瘍穿孔に対して広範囲胃切除術、Billroth II法再建を施行された。心窩部不快感が出現し、上部消化管内視鏡検査(EGD)を施行し、吻合部に小彎を中心とする2/3周性の1型腫瘍を認め、生検ではadenocarcinomaと診断した。残胃吻合部癌の診断で手術を施行したが、腹膜播種および膵浸潤を認め試験開腹術となった。化学療法を施行するも奏効せず、繰り返す嘔吐を認め、経口摂取不良となった。EGDではBillroth II法吻合部に易出血性の隆起性腫瘍を認め、内腔は狭小化し、スコープは通過困難であった。悪性腫瘍に伴う吻合部狭窄と診断し、SEMS挿入を行う方針となった。翌日から経口摂取可能となり退院となった。外来化学療法を施行したが、SEMS挿入3ヵ月後に全身状態が悪化し死亡した。経口摂取は直前まで保たれていた。