Significance and Amplification Methods of the Purine Salvage Pathway in Human Brain Cells.

Previous studies suggest that uric acid or reactive oxygen species, products of xanthine oxidoreductase (XOR), may associate with neurodegenerative diseases. However, neither relationship has ever been firmly established. Here, we analyzed human brain samples, obtained under protocols approved by research ethics committees, and found no expression of XOR and only low levels of uric acid in various regions of the brain. In the absence of XOR, hypoxanthine will be preserved and available for incorporation into the purine salvage pathway. To clarify the importance of salvage in the brain, we tested using human induced pluripotent stem cell-derived neuronal cells. Stable isotope analyses showed that the purine salvage pathway was more effective for ATP synthesis than purine de novo synthesis. Blood uric acid levels were related to the intracellular adenylate pool (ATP + ADP + AMP), and reduced levels of this pool result in lower uric acid levels. XOR inhibitors are related to extracellular hypoxanthine levels available for uptake into the purine salvage pathway by inhibiting the oxidation of hypoxanthine to xanthine and uric acid in various organs where XOR is present and can prevent further decreases in the intracellular adenylate pool under stress. Furthermore, adding precursors of the pentose phosphate pathway enhanced hypoxanthine uptake, indicating that purine salvage is activated by PRPP replenishment. These findings resolve previous contradictions regarding XOR products and provide new insights into clinical studies. It is suggested that therapeutic strategies maximizing maintenance of intracellular adenylate levels may effectively treat pathological conditions associated with ischemia and energy depletion.

Allopurinol and oxypurinol differ in their strength and mechanisms of inhibition of xanthine oxidoreductase.

Xanthine oxidoreductase is a metalloenzyme that catalyzes the final steps in purine metabolism by converting hypoxanthine to xanthine and then uric acid. Allopurinol, an analog of hypoxanthine, is widely used as an antigout drug, as xanthine oxidoreductase-mediated metabolism of allopurinol to oxypurinol leads to oxypurinol rotation in the enzyme active site and reduction of the molybdenum Mo(VI) active center to Mo(IV), inhibiting subsequent urate production. However, when oxypurinol is administered directly to a mouse model of hyperuricemia, it yields a weaker urate-lowering effect than allopurinol. To better understand its mechanism of inhibition and inform patient dosing strategies, we performed kinetic and structural analyses of the inhibitory activity of oxypurinol. Our results demonstrated that oxypurinol was less effective than allopurinol both in vivo and in vitro. We show that upon reoxidation to Mo(VI), oxypurinol binding is greatly weakened, and reduction by xanthine, hypoxanthine, or allopurinol is required for reformation of the inhibitor-enzyme complex. In addition, we show oxypurinol only weakly inhibits the conversion of hypoxanthine to xanthine and is therefore unlikely to affect the feedback inhibition of de novo purine synthesis. Furthermore, we observed weak allosteric inhibition of purine nucleoside phosphorylase by oxypurinol which has potentially adverse effects for patients. Considering these results, we propose the single-dose method currently used to treat hyperuricemia can result in unnecessarily high levels of allopurinol. While the short half-life of allopurinol in blood suggests that oxypurinol is responsible for enzyme inhibition, we anticipate multiple, smaller doses of allopurinol would reduce the total allopurinol patient load.

XDH and XO Research and Drug Discovery-Personal History.

The author will outline the research history of the main issues addressed in this paper. The author has worked on this research himself. XDH, which is responsible for purine degradation, is present in various organisms. However, conversion to XO only occurs in mammals. The molecular mechanism of this conversion was elucidated in this study. The physiological and pathological significance of this conversion is presented. Finally, enzyme inhibitors were successfully developed, two of which are used as therapeutic agents for gout. Their wide application potential is also discussed.

Impact of preoperative 6-minute walk distance on long-term prognosis after esophagectomy in patients with esophageal cancer.

BACKGROUND: The 6-minute walk distance (6MWD) is a simple way of assessing exercise capacity. The purpose of this study was to investigate the relationship between preoperative 6MWD and long-term prognosis after esophagectomy. METHODS: This retrospective cohort study involved 108 patients who underwent radical esophagectomy for esophageal cancer between 2013 and 2020. The patients were classified into the short group (SG: 6MWD < 480 m) or the long group (LG: 6MWD ≥ 480 m). To adjust for the background characteristics of both groups, propensity score matching (PSM) analysis was performed and 32 patients were matched from each group. Five-year overall survival (OS) and relapse-free survival (RFS) were analyzed by the Kaplan-Meier method. The log-rank test was used to evaluate differences in survival between the groups. After adjusting for other prognostic factors, the Cox proportional hazards model was used to investigate the impact of preoperative 6MWD on long-term prognosis. RESULTS: The median follow-up period was 923 days. Thirty-three deaths were recorded during the study period. After PSM, 5-year OS following surgery was 29.2 and 66.1% (p = 0.003) and 5-year RFS was 27.9 and 58.6% (p = 0.021) in the SG and LG, respectively. In Cox proportional hazards analysis, the SG was a significant independent risk factor for OS (hazard ratio 3.33; 95% confidence interval 1.37-8.11, p = 0.008) and RFS (hazard ratio 2.30; 95% confidence interval 1.08-4.88, p = 0.030). CONCLUSION: The preoperative 6MWD is useful for evaluating exercise capacity and predicting the long-term outcome in patients undergoing esophagectomy.

Endobronchial Ultrasound Improves the Diagnosis of the Tracheobronchial Invasion of Advanced Esophageal Cancer.

BACKGROUND: Accurate diagnosis of the tracheobronchial invasion of advanced esophageal cancer is essential to select appropriate treatment and improve prognosis; however, it is difficult using the conventional modalities. This study aimed to clarify the diagnostic usefulness of convex probe endobronchial ultrasound (CP-EBUS) for the diagnosis of the tracheobronchial invasion of advanced esophageal cancer. METHODS: We conducted a cadaveric study to clarify the changes in ultrasonic and histopathologic findings in the esophageal tumor and tracheal invasion models. Additionally, we examined CP-EBUS for patients with advanced thoracic esophageal cancer in whom tracheobronchial invasion was suspected on contrast-enhanced computed tomography (CE-CT) scan. We retrospectivity evaluated the diagnosis of CP-EBUS, comparing the pathological findings and treatment outcomes. RESULTS: Cadaveric esophageal tumor and tracheal invasion models showed the disappearance of the third layer observed with CP-EBUS and histologically proven interruption of the adventitia. This indicated that the third layer corresponded with the tracheal adventitia. We examined 40 patients with advanced thoracic esophageal cancer in whom tracheobronchial invasion was suspected. The precise diagnosis was pathologically confirmed in 9 of 14 patients diagnosed with cT3 who underwent radical surgery. 20 of 26 cases diagnosed with cT4b received definitive chemoradiotherapy, and 4 cases received salvage surgery and pathologically confirmed precise diagnosis. CONCLUSION: CP-EBUS is extremely useful for diagnosing the tracheobronchial invasion of advanced esophageal cancer. It could be an effective modality for determining treatment strategies in cases with a marginal surgical indication.

The sterno-tracheal distance is an important factor of anastomotic leakage of retrosternal gastric tube reconstruction after esophagectomy.

BACKGROUND: Anastomotic leakage (AL) is a serious complication after esophagectomy. The retrosternal (RS) route has been selected majorly to reduce reflux and related pneumonia and considering mediastinal recurrences. AL has been developed more in RS than posterior mediastinal (PM) route reconstruction. Therefore, we suspected the sterno-tracheal distance (STD) might be related to AL and started the selection according to the STD from 2009. METHODS: A total of 221 patients who underwent a subtotal esophagectomy with gastric tube reconstruction during January 2004-April 2017 were investigated. The patients were classified into the 'after STD selection' (A; n = 144) group and the 'before STD selection' (B, n = 77) group. The incidences of and the risk factors for AL between the two groups were compared. RESULTS: The incidence of AL was high in the B group (18.2%), and 78.6% of the patients who developed AL were treated with RS route reconstruction. The median STDs of the patients with AL and no AL were 10.3 mm and 14.5 mm, respectively (p = 0.001). These results demonstrated that the STD was a risk factor for AL in the RS route. Based on these results, 13 mm was set as the cutoff value. After STD selection, the median STD increased from 14.0 to 17.3 mm (p = 0.001), and the incidence of AL decreased significantly from 26.2 to 11.1% in the RS route (p = 0.037). CONCLUSION: The STD was the independent risk factor for AL in the RS route. RS route reconstruction should be avoided for the patients with STD < 13 mm.

The effects of the herbal medicine Daikenchuto (TJ-100) after esophageal cancer resection, open-label, randomized controlled trial.

BACKGROUND: Daikenchuto (TJ-100), a traditional Japanese herbal medicine, is widely used in Japan. Its effects on gastrointestinal motility and microcirculation and its anti-inflammatory effect are known. The purpose of this prospective randomized controlled trial was to investigate the effect of TJ-100 after esophagectomy in esophageal cancer patients. METHODS: Forty patients for whom subtotal esophageal resection for esophageal cancer was planned at our institute from March 2011 to August 2013 were enrolled and divided into two groups at the point of determination of the operation schedule after informed consent was obtained: a TJ-100 (15 g/day)-treated group (n = 20) and a control group (n = 20). The primary efficacy end-points were maintenance of the nutrition condition and the recovery of gastrointestinal function. The secondary efficacy end-points were the serum C-reactive protein (CRP) level and adrenomedullin level during the postoperative course, the incidence of postoperative complications, and the length of hospital stay after surgery. RESULTS: We examined 39 patients because one patient in the TJ-100 group was judged as having unresectable cancer after surgery. The mean age of the TJ-100 group patients was significantly older than that of the control group patients.The rate of body weight decrease at postoperative day 21 was significantly suppressed in the TJ-100 group (3.6% vs. the control group: 7.0%, p = 0.014), but the serum albumin level was not significantly different between the groups. The recovery of gastrointestinal function regarding flatus, defecation, and oral intake showed no significant between-group differences, but postoperative bowel symptoms tended to be rare in the TJ-100 group. There was no significant between-group difference in the length of hospital stay after surgery. The serum CRP level at postoperative day 3 was 4.9 mg/dl in the TJ-100 group and 6.9 mg/dl in the control group, showing a tendency of a suppressed serum CRP level in the TJ-100 group (p = 0.126). The rate of increase in adrenomedullin tended to be high postoperatively, but there was no significant difference between the two groups. CONCLUSIONS: TJ-100 treatment after esophageal cancer resection has the effects of prompting the recovery of gastrointestinal motility and minimizing body weight loss, and it might suppress the excess inflammatory reaction related to surgery.

CXCR4 Expression is Associated with Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma.

BACKGROUND: Chemokines and their receptors are known to play important roles in the tumorigenesis of many malignancies. The chemokine CXCL12 and its receptors CXCR4 and CXCR7 were suggested to be involved in cancer invasion and metastasis. The aim of this retrospective study was to evaluate the prognostic impact of the expressions of CXCL12, CXCR4 and CXCR7 in patients with esophageal squamous cell carcinoma (ESCC). METHODS: We used immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR) to evaluate the expressions of CXCL12, CXCR4, and CXCR7 in ESCC patients' tumor biopsy specimens obtained during preoperative endoscopy or surgery. These results were compared with the patients' clinicopathological parameters and survival. RESULTS: IHC was conducted for 172 patients. High expression of CXCR4 in the cytoplasm and nuclei and that of CXCR7 were associated with poor cause-specific survival (CSS) (P= .002 and .010, respectively). The specimens from 52 of the 172 patients were examined by RT-PCR and quantitative real-time PCR. The expression levels of messenger RNA (mRNA) of CXCR4 and CXCR7 were significantly increased in the tumors compared with normal esophageal mucosae (P < .0001). The expression level of mRNA of CXCR4 was associated with poor recurrence-free survival and CSS (P = .012 and .038, respectively). CONCLUSIONS: CXCR4 expression is associated with poor prognosis in patients with ESCC.

[Malignant Pleural Mesothelioma Presenting Refractory Pneumothorax Successfully Treated by Intrapleural Administration of Diluted Fibrin Glue;Report of a Case].

Malignant pleural mesothelioma sometimes accompanies intractable neumothorax due to the visceral pleural invasion of the tumor. A 68-years-old man was found to have massive pleural effusion and pleural mass combined with pneumothorax by computed tomography(CT). CT guided biopsy revealed the mass to be malignant pleural mesothelioma. Since continuous air leakage was observed by chest drainage, pleurodesis by OK-432 twice and bronchial occlusion by Endobronchial Watanabe Spigot (EWS)were performed. But air leakage continued, and the surgery was performed, however the treatment failed to stop the air leakage. Finally, the intrapleural administration of diluted fibrin glue was challenged and the air leakage stopped immediately after the treatment.

[PERIOPERATIVE ORAL MANAGEMENT FOR ESOPHAGEAL CANCER AND LUNG CANCER SURGERY].

The effectiveness of perioperative oral management in decreasing the risk of postoperative pneumonia has been reported recently. We introduced perioperative oral management for esophageal cancer and lung cancer patients in 2014 and report here its current status and effectiveness for those patients in our institute. Every 100 cases of esophageal cancer and lung cancer patients treated surgically were classified into two groups, i.e., with or without perioperative oral management, and postoperative complications were compared retrospectively. In the lung cancer group, oral management prevented postoperative pneumonia significantly and shortened the length of hospital stays after surgery in comparison with the group without oral management. In the esophageal cancer group, there was little occurrence of postoperative pneumonia in either group. Numerous esophageal cancer patients who received neoadjuvant chemotherapy developed oral mucositis and received oral care treatment before surgery. Such treatment for oral mucositis likely improved the oral environment and prevented postoperative pneumonia. Other patients have also been introduced to the importance of oral care before chemotherapy. Perioperative oral management can prevent postoperative pneumonia in esophageal cancer and lung cancer patients.

[Current Status and Effectiveness of Perioperative Oral Health Care Management for Lung Cancer and Esophageal Cancer Patients].

The effectiveness of perioperative oral health care management to decrease the risk of postoperative pneumonia have been reported lately. Since 2014, we introduced perioperative oral health care management for lung cancer and esophageal cancer patients. We report current status and effectiveness of perioperative oral health care management for lung cancer and esophageal cancer patients. Every 100 cases of lung cancer and esophageal cancer patients treated by surgery were classified 2 group with or without perioperative oral health care management and compared about postoperative complications retrospectively. In the lung cancer patients, the group with oral health care management could prevent postoperative pneumonia significantly and had shorter length of hospital stay than the group without oral health care management. In the esophageal cancer patients, there was little occurrence of postoperative pneumonia without significant difference between both group with or without oral health care management. A large number of esophageal cancer patients received neo-adjuvant chemotherapy and some patients developed oral mucositis and received oral care treatment before surgery. Treatment for oral mucositis probably improved oral environment and affected prevention of postoperative pneumonia. Perioperative oral health care management can prevent postoperative pneumonia of lung cancer and esophageal cancer patients by improvement of oral hygiene.

Mechanistic insights into xanthine oxidoreductase from development studies of candidate drugs to treat hyperuricemia and gout.

Xanthine oxidoreductase (XOR), which is widely distributed from humans to bacteria, has a key role in purine catabolism, catalyzing two steps of sequential hydroxylation from hypoxanthine to xanthine and from xanthine to urate at its molybdenum cofactor (Moco). Human XOR is considered to be a target of drugs not only for therapy of hyperuricemia and gout, but also potentially for a wide variety of other diseases. In this review, we focus on studies of XOR inhibitors and their implications for understanding the chemical nature and reaction mechanism of the Moco active site of XOR. We also discuss further experimental or clinical studies that would be helpful to clarify remaining issues.

[Pathological complete response in a case of advanced esophageal cancer invading aorta treated by preoperative chemotherapy with docetaxel and cisplatin plus 5-FU].

The patient was a 64-year-old man, diagnosed as cStage IVa esophageal cancer invading the aorta with lymph node metastasis. He received combination chemotherapy with docetaxel/cisplatin/5-FU(DFP therapy). After one course, CT and endoscopic examination showed remarkable reduction of the primary lesion and lymph node metastasis. We performed subtotal esophagectomy and gastric tube reconstruction by the retroposterior mediastinum route. The pathological specimen evidenced fibrosis and infiltration of inflammatory cells on almost all layers, but showed no viable malignant cells in the middle thoracic esophagus. Therefore, the pathological effect was judged as Grade 3(pCR). This case suggested that DFP combination chemotherapy may prove to be a useful treatment for advanced esophageal cancer with invasion to other organs.

The mechanism and significance of the conversion of xanthine dehydrogenase to xanthine oxidase in mammalian secretory gland cells.

The conversion of xanthine dehydrogenase (XDH) to xanthine oxidase (XO) occurs only in mammalian species. In fresh bovine milk, the enzyme exists predominantly as the oxidase form, in contrast to various normal organs where it is found primarily as the dehydrogenase: the mechanism of conversion to the oxidase in milk remains obscure. A systematic search for the essential factors for conversion from XDH to XO has been performed within fresh bovine milk using the highly purified dehydrogenase form after removal endogenous oxidase form by fractionation analysis. We find that conversion to the oxidase form requires four components under air: lactoperoxidase (LPO), XDH, SCN-, and substrate hypoxanthine or xanthine; the contribution of sulfhydryl oxidase appears to be minor. Disulfide bond formation between Cys-535 and Cys-995 is principally involved in the conversion, consistent with the result obtained from previous work with transgenic mice. In vitro reconstitution of LPO and SCN- results in synergistic conversion of the dehydrogenase to the oxidase the presence of xanthine, indicating the conversion is autocatalytic. Milk from an LPO knockout mouse contains a significantly greater proportion of the dehydrogenase form of the enzyme, although some oxidase form is also present, indicating that LPO contributes principally to the conversion, but that sulfhydryl oxidase (SO) may also be involved to a minor extent. All the components XDH/LPO/SCN- are necessary to inhibit bacterial growth in the presence of xanthine through disulfide bond formation in bacterial protein(s) required for replication, as part of an innate immunity system in mammals. Human GTEx Data suggest that mRNA of XDH and LPO are highly co-expressed in the salivary gland, mammary gland, mucosa of the airway and lung alveoli, and we have confirmed these human GTEx Data experimentally in mice. We discuss the possible roles of these components in the propagation of SARS-CoV-2 in these human cell types.

Protein conformational gating of enzymatic activity in xanthine oxidoreductase.

In mammals, xanthine oxidoreductase can exist as xanthine dehydrogenase (XDH) and xanthine oxidase (XO). The two enzymes possess common redox active cofactors, which form an electron transfer (ET) pathway terminated by a flavin cofactor. In spite of identical protein primary structures, the redox potential difference between XDH and XO for the flavin semiquinone/hydroquinone pair (E(sq/hq)) is ~170 mV, a striking difference. The former greatly prefers NAD(+) as ultimate substrate for ET from the iron-sulfur cluster FeS-II via flavin while the latter only accepts dioxygen. In XDH (without NAD(+)), however, the redox potential of the electron donor FeS-II is 180 mV higher than that for the acceptor flavin, yielding an energetically uphill ET. On the basis of new 1.65, 2.3, 1.9, and 2.2 Å resolution crystal structures for XDH, XO, the NAD(+)- and NADH-complexed XDH, E(sq/hq) were calculated to better understand how the enzyme activates an ET from FeS-II to flavin. The majority of the E(sq/hq) difference between XDH and XO originates from a conformational change in the loop at positions 423-433 near the flavin binding site, causing the differences in stability of the semiquinone state. There was no large conformational change observed in response to NAD(+) binding at XDH. Instead, the positive charge of the NAD(+) ring, deprotonation of Asp429, and capping of the bulk surface of the flavin by the NAD(+) molecule all contribute to altering E(sq/hq) upon NAD(+) binding to XDH.

Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative CT lymphography for superficial esophageal cancer.

BACKGROUND: The sentinel lymph node (SLN) concept has been gaining attention for gastrointestinal neoplasms but remains controversial for esophageal cancer. This study evaluated the feasibility of SLN identification using intraoperative indocyanine green (ICG) fluorescence imaging (IGFI) navigated by preoperative computed tomographic lymphography (CTLG) to treat superficial esophageal cancer. METHODS: Subjects comprised 20 patients clinically diagnosed with superficial esophageal cancer. Five minutes after endoscopic submucosal injection of iopamidol around the primary lesion using a four-quadrant injection pattern with a 23-gauge endoscopic injection sclerotherapy needle, three-dimensional multidetector computed tomography was performed to identify SLNs and lymphatic routes. ICG solution was injected intraoperatively around the tumor. Fluorescence imaging was obtained by infrared ray electronic endoscopy. Thoracoscope-assisted standard radical esophagectomy with lymphadenectomy was performed to confirm fluorescent lymph nodes detected by CTLG. RESULTS: Lymphatic vessels and SLNs were identified preoperatively using CTLG in all cases. Intraoperative detection rates were 100% using CTLG and 95% using IGFI. Lymph node metastases were found in four cases, including one false-negative case with SLNs occupied by bulky metastatic tumor that were not enhanced with both methods. The other 19 cases, including three cases of metastatic lymph nodes, were accurately identified by both procedures. CONCLUSIONS: Preoperative CTLG visualized the correct number and site of SLNs in surrounding anatomy during routine computed tomography to evaluate distant metastases. Referring to CTLG, SLNs were identified using IGFI, resulting in successful SLN navigation and saving time and cost. This method appears clinically applicable as a less-invasive method for treating superficial esophageal cancer.

Mutations associated with functional disorder of xanthine oxidoreductase and hereditary xanthinuria in humans.

Xanthine oxidoreductase (XOR) catalyzes the conversion of hypoxanthine to xanthine and xanthine to uric acid with concomitant reduction of either NAD+ or O(2). The enzyme is a target of drugs to treat hyperuricemia, gout and reactive oxygen-related diseases. Human diseases associated with genetically determined dysfunction of XOR are termed xanthinuria, because of the excretion of xanthine in urine. Xanthinuria is classified into two subtypes, type I and type II. Type I xanthinuria involves XOR deficiency due to genetic defect of XOR, whereas type II xanthinuria involves dual deficiency of XOR and aldehyde oxidase (AO, a molybdoflavo enzyme similar to XOR) due to genetic defect in the molybdenum cofactor sulfurase. Molybdenum cofactor deficiency is associated with triple deficiency of XOR, AO and sulfite oxidase, due to defective synthesis of molybdopterin, which is a precursor of molybdenum cofactor for all three enzymes. The present review focuses on mutation or chemical modification studies of mammalian XOR, as well as on XOR mutations identified in humans, aimed at understanding the reaction mechanism of XOR and the relevance of mutated XORs as models to estimate the possible side effects of clinical application of XOR inhibitors.

[A case of sigmoid colon cancer invading urinary bladder treated with preoperative mFOLFOX6 and urinary bladder conserving surgery].

A 69-year-old man visited our hospital because of melena and anemia. Colonoscopy revealed a type 3 tumor at sigmoid colon, and by abdominal CT, we detected a sigmoid colon cancer invading the urinary bladder with a single liver metastasis. The patient required sigmoidectomy with partial hepatectomy and total urinary bladder resection. Preoperative chemotherapy with mFOLFOX6 was initiated as a part of multidisciplinary therapy. After the 6th course was completed, CT revealed a reduction in the primary tumor's size and the disappearance of liver metastasis. After the 8th course was completed, we performed urinary bladder conserving sigmoidectomy. The pathological diagnosis of the surgical specimen was tub1, pSS, ly0, v0, pN0, and pStage II. Down-sizing chemotherapy might improve the quality of life(QOL)of colon cancer patients with extensive invasion of the urinary bladder.

A case of aortoduodenal fistula presenting with postoperative lymphatic leakage.

INTRODUCTION AND IMPORTANCE: Secondary aortoduodenal fistula (sADF) is a complication of prosthetic graft replacement of the abdominal aorta which often follows a fatal course. This report details our experience with a case of lymphatic fistula that developed after sADF repair. The fistula was refractory to conservative treatment but ultimately responded to lipiodol lymphangiography. CASE PRESENTATION: A 75-year-old man had undergone prosthetic graft replacement to treat an abdominal aortic aneurysm in 2012 and a thoracic aortic aneurysm in 2015. Upper gastrointestinal endoscopy was performed in 2020, and examination for worsening anemia revealed that the abdominal aortic graft had eroded into the horizontal duodenum. The patient was treated with prosthetic graft replacement and duodenectomy. A refractory lymphatic fistula was noted after surgery, which made ascites accumulation difficult to control, but the patient's condition rapidly improved following therapeutic lymphangiography. CLINICAL DISCUSSION: Surgery is the first-line therapy for sADF, but clinicians must stay vigilant for infection recurrence and aortoenteric fistulae after a repair, and this requires patient-specific postoperative management. Our modifications, intended to minimize contamination of the operative field in the present case, also facilitated our ability to subsequently treat a refractory lymphatic fistula, which is a rare postoperative complication of the procedure. CONCLUSION: Procedural modifications to sADF repair aimed at minimizing perioperative contamination are crucial for preventing infection recurrence. Given the extent of invasion, the surgery can cause various postoperative complications, requiring individualized strategies for management and treatment. Therapeutic lymphangiography is one such approach, which holds promise as a first-line treatment for refractory lymphatic fistula.

Spontaneous esophageal perforation within a hiatal hernia: A case report.

INTRODUCTION: Spontaneous esophageal perforation, also commonly referred to as Boerhaave's syndrome, is one of the most lethal diseases causing an acute abdomen. Though rare, emergent surgical intervention is often required and management can be various based upon the site of the perforation. This literature has been written in line with the SCARE criteria (Agha et al., 2020) [1]. PRESENTATION OF CASE: A 76-year-old man presented with acute abdominal pain. Computed tomography (CT) revealed and an emergent esophagogastroduodenoscopy (EGD) was performed carefully, which revealed a 7 cm all-layer esophageal laceration in the left lower esophageal wall. In our case, a hiatal hernia was protruding into the mediastinum, and the perforation site was inside of it, but there was no invasion into the thoracic cavity, thus a transabdominal approach was performed without thoracotomy. DISCUSSION: This type of esophageal perforation within a hiatal hernia is quite rare and provides a unique clinical challenge. In addition, A review reported the average length of spontaneous esophageal perforation to be around 2 cm while our case had a perforation with a length of 7 cm. We chose the combination of the simple suture with omental buttress and wide drainage, but a complete fundoplication was impossible due to its large size of perforation. CONCLUSION: We chose the open abdominal approach because the case had high inflammation, a hiatal hernia and possibility of retro-gastric perforation. However, MIS should have been considered first if a situation or human resources allow it.