Updated evidence of the effectiveness and safety of transanal drainage tube for the prevention of anastomotic leakage after rectal low anterior resection: a systematic review and meta-analysis.

BACKGROUNDS: Anastomotic leakage (AL) represents a major complication after rectal low anterior resection (LAR). Transanal drainage tube (TDT) placement offers a potential strategy for AL prevention; however, its efficacy and safety remain contentious. METHODS: A systematic review and meta-analysis were used to evaluate the influence of TDT subsequent to LAR as part of the revision of the surgical site infection prevention guidelines of the Japanese Society of Surgical Infectious Diseases (PROSPERO registration; CRD42023476655). We searched each database, and included randomized controlled trials (RCTs) and observational studies (OBSs) comparing TDT and non-TDT outcomes. The main outcome was AL. Data were independently extracted by three authors and random-effects models were implemented. RESULTS: A total of three RCTs and 18 OBSs were included. RCTs reported no significant difference in AL rate between the TDT and non-TDT groups [relative risk (RR): 0.69, 95% confidence interval (CI) 0.42-1.15]. OBSs reported that TDT reduced AL risk [odds ratio (OR): 0.45, 95% CI 0.31-0.64]. In the subgroup excluding diverting stoma (DS), TDT significantly lowered the AL rate in RCTs (RR: 0.57, 95% CI 0.33-0.99) and OBSs (OR: 0.41, 95% CI 0.27-0.62). Reoperation rates were significantly lower in the TDT without DS groups in both RCTs (RR: 0.26, 95% CI 0.07-0.94) and OBSs (OR: 0.40, 95% CI 0.24-0.66). TDT groups exhibited a higher anastomotic bleeding rate only in RCTs (RR: 4.28, 95% CI 2.14-8.54), while shorter hospital stays were observed in RCTs [standard mean difference (SMD): -0.44, 95% CI -0.65 to -0.23] and OBSs (SMD: -0.54, 95% CI -0.97 to -0.11) compared with the non-TDT group. CONCLUSIONS: A universal TDT placement cannot be recommended for all rectal LAR patients. Some patients may benefit from TDT, such as patients without DS creation. Further investigation is necessary to identify the specific beneficiaries.

Background rates of x-ray transition-edge sensor micro-calorimeters under a frequency domain multiplexing readout for solar axion-like particles' detection.

We report on the x-ray background rate measured with transition-edge sensors (TES) micro-calorimeters under frequency-domain multiplexing (FDM) readout as a possible technology for future experiments aiming at a direct detection of axion-like particles. Future axion helioscopes will make use of large magnets to convert axions into photons in the keV range and x-ray detectors to observe them. To achieve this, a detector array with high spectral performance and extremely low background is necessary. TES are single-photon, non-dispersive, high-resolution micro-calorimeters and represent a possible candidate for this application. We have been developing x-ray TES micro-calorimeters and an FDM readout technology in the framework of the space-borne x-ray astronomical observatories. We show that the current generation of our detectors is already a promising technology for a possible axion search experiment, having measured an x-ray background rate of 2.2(2) × 10-4 cm-2 s-1 keV-1 with a cryogenic demonstrator not optimized for this specific application. We then make a prospect to further improve the background rate down to the required value (<10-7 cm-2 s-1 keV-1) for an axion-search experiment, identifying no fundamental limits to reach such a level.

Securing the surgical field for mobilization of right-sided colon cancer using the duodenum-first multidirectional approach in laparoscopic surgery.

BACKGROUND: The aim of this study was to compare the short-term outcomes of the duodenum-first multidirectional approach (DMA) in laparoscopic right colectomy with those of the conventional medial approach to assess its safety and feasibility. METHODS: This retrospective study enrolled 120 patients who had laparoscopic surgery for right-sided colon cancer in our institution between April 2013 and December 2019. Fifty-four patients underwent colectomy using the multidirectional approach; among these, 20 underwent the DMA and 34 underwent the caudal-first multidirectional approach (CMA). Sixty-six patients underwent the conventional medial approach. Complications within 30 days of surgery were compared between the groups. RESULTS: There were 54 patients in the multidirectional group [29 females, median age 72 years (range 36-91 years)] and 66 in the medial group [42 females, median age 72 years (range 41-91 years)]. Total operative time was significantly shorter in multidirectional approach patients than conventional medial approach patients (208 min vs. 271 min; p = 0.01) and significantly shorter in patients who underwent the DMA compared to the CMA (201 min vs. 269 min; p < 0.001). Operative time for the mobilization procedure was also significantly shorter in patients who underwent the DMA (131 min vs. 181 min; p < 0.001). Blood loss and incidence of postoperative complications did not differ. In 77 patients with advanced T3/T4 tumors, the DMA, CMA, and conventional medial approach were performed in 13, 21, and 43 patients, respectively. Total operative time and operative time of the mobilization procedure were significantly shorter in patients undergoing DMA. Blood loss and incidence of postoperative complications did not differ. R0 resection was achieved in all patients with advanced tumors. CONCLUSIONS: The DMA in laparoscopic right colectomy is safe and feasible and can achieve R0 resection with a shorter operative time than the conventional medial approach, even in patients with advanced tumors.

Frequency shift algorithm: Application to a frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters.

In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.

Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters.

Uniform large transition-edge sensor (TES) arrays are fundamental for the next generation of x-ray space observatories. These arrays are required to achieve an energy resolution ΔE < 3 eV full width at half maximum (FWHM) in the soft x-ray energy range. We are currently developing x-ray microcalorimeter arrays for use in the future laboratory and space-based x-ray astrophysics experiments and ground-based spectrometers. In this contribution, we report on the development and the characterization of a uniform 32 × 32 pixel array with 140 × 30 µm2 Ti/Au TESs with the Au x-ray absorber. We report on extensive measurements on 60 pixels in order to show the uniformity of our large TES array. The averaged critical temperature is Tc = 89.5 ± 0.5 mK, and the variation across the array (∼1 cm) is less than 1.5 mK. We found a large region of detector's bias points between 20% and 40% of the normal-state resistance where the energy resolution is constantly lower than 3 eV. In particular, results show a summed x-ray spectral resolution ΔEFWHM = 2.50 ± 0.04 eV at a photon energy of 5.9 keV, measured in a single-pixel mode using a frequency domain multiplexing readout system developed at SRON/VTT at bias frequencies ranging from 1 MHz to 5 MHz. Moreover, we compare the logarithmic resistance sensitivity with respect to temperature and current (α and ß, respectively) and their correlation with the detector's noise parameter M, showing a homogeneous behavior for all the measured pixels in the array.

Atrophic change of the abdominal rectus muscle significantly influences the onset of parastomal hernias beyond existing risk factors after end colostomy.

PURPOSE: To investigate optimal risk factors, including atrophy of the abdominal rectus muscle (ARM) for postoperative parastomal hernia (PH) in patients who underwent end colostomy at left lower quadrant. METHODS: This single-institution retrospective study included 91 patients who underwent end colostomy between April 2004 and December 2015. The surgical and long-term outcomes among patients with or without PH were collected and compared. RESULTS: Altogether, 22 (24.2%) patients had a PH including 15 (68.2%) patients with a simultaneous incisional hernia. Univariate analysis showed that older patients (71 ± 11.9 vs. 64 ± 12.2 years, p = 0.03) and those with higher body mass index (BMI) (23.8 ± 3.8 vs. 20.9 ± 3.3 kg/m2, p < 0.001) had a statistically significant relation with having PHs. Relative atrophy of left abdominal rectus muscle was more frequently found in patients with PH (ratio of left side/right side; caudal level and medial side: 0.66 vs. 0.92, p < 0.01, caudal level and lateral side: 0.95 vs. 1.03, p = 0.04). Multivariate analysis revealed that BMI > 25 kg/m2 [odds ratio (OR) 9.05, 95% confidence interval (CI) 2.06-39.76, p = 0.003] and atrophy of the left lower medial portion of the abdominal rectus muscle (OR 12.85, 95% CI 2.49-66.39, p = 0.002) were independent risk factors for PHs. Neither the laparoscopic approach nor the extraperitoneal route of the colostomy was proven to correlate with a lower rate of PHs. CONCLUSIONS: High BMI and atrophic change of ARM were significantly associated with PH development. Surgical techniques for prevention of atrophic change of ARM are expected to reduce the incidence of PHs.

Laparoscopic en bloc excision of gastrointestinal stromal tumors of the rectum after neoadjuvant imatinib therapy: anteriorly extended intersphincteric resection combined with partial resection of the prostate.

We herein present a novel technique for laparoscopic en bloc excision involving anteriorly extended intersphincteric resection with partial resection of the posterior lobe of the prostate for large rectal gastrointestinal stromal tumors (GISTs). The sequence of neoadjuvant imatinib therapy and this less invasive surgery for marginally resectable rectal GISTs has the potential to obviate the need for urinary reconstruction and permanent stomas without jeopardizing the tumor margin status.

[Retrogastric colon mimicking foramen of Winslow hernia or left paraduodenal hernia: case report].

We report the case of a 54-year-old woman who developed epigastralgia and vomit. Because of the abnormal gas in the epigastrium on abdominal X-ray, ileus due to foramen of Winslow hernia or left paraduodenal hernia was suspected. However, abdominal CT and barium study revealed the gas in the epigastrium to be the air in the transverse colon interposed between the stomach and pancreatic body. This anomalous interposition of the transverse colon is called retrogastric colon. The ileus was due to non-specific inflammatory duodenal stenosis. It is important to prevent misdiagnosis of retrogastric colon as lesser sac pathologic condition such as abscess, bowel perforation and internal hernia.

Diffusion-weighted echo planar imaging of the normal human cervical spinal cord.

We obtained diffusion-weighted echo planar images of the human cervical cord in vivo and correlated them with histopathologic findings. Images were obtained in 17 healthy volunteers using a 1.5 T clinical MR unit. When motion-probing gradients were added perpendicular to the long axis of the cord, the white matter was hyperintense because of anisotropic diffusion. However, the gracile fasciculus was hypointense probably due to the small diameter of neural fibers and the large extracellular space.

[Usefulness of selective cerebral angiography by transradial approach].

Transradial angiography has recently emerged as an alternative to the transfemoral or transbrachial approach, especially for coronary procedures. However, there have been few studies on cerebral angiography using the transradial approach. The purpose of this study was to assess the outcomes, complications, and limitations of selective cerebral angiography via the transradial approach. Selective cerebral angiography by the right transradial approach using 100-cm-long 4-F catheters was performed in 83 patients. Using five types of catheters, the success rates of selective catheterization to the right vertebral artery, right common carotid artery, left common carotid artery, and left vertebral artery were 40/44 (91%), 68/68 (100%), 62/62 (100%), and 14/25 (56%), respectively. Puncture failed in one patient, and a guidewire could not be introduced beyond the radial artery loop in one patient. Radial artery spasm occurred in one patient, but was relieved immediately after nitroglycerin injection through the sheath with side holes. Subcutaneous bleeding occurred in six patients, but no obvious hematomas were noted. Occlusion or stenosis of the radial artery occurred in five patients, but no ischemic symptoms were observed in any of the cases. This study suggested that selective cerebral angiography can be performed safely using the transradial approach.

[Delineation of calf arteries using 2D-TOF MR angiography without contrast medium: efficacy of cardiac gating and leg warming].

We evaluated the image quality of non-contrast enhanced 2D-TOF MRA of the calf and the efficacy of cardiac gating and leg warming. In 10 healthy volunteers, MRA was carried out under the following four conditions: (a) usual MRA, (b) MRA with cardiac gating, (c) MRA after leg warming and (d) MRA with cardiac gating after leg warming. Although MRA with cardiac gating was not suitable, MRA after leg warming was well suited to the imaging of calf arteries. The image quality of MRA with cardiac gating after leg warming was the same as that of MRA after leg warming.

[Delineation of the white and gray matter of the normal human cervical spinal cord using diffusion-weighted echo planar imaging].

To delineate the white and gray matter of the normal human cervical spinal cord, diffusion-weighted echo planar imaging (DW-EPI) was performed in 11 healthy volunteers. Three axial (X-, Y- and Z-axis) anisotrophic diffusion-weighted images were obtained on a 1.5T superconducting clinical unit using a single-shot DW-EPI sequence. On X- and Y-axis DWIs the white and gray matter could be well differentiated: the former showed high intensity and the latter low intensity. Anterior columns were clearly visible, whereas posterior columns were not. On Z-axis DWI the white and gray matter could not be differentiated at all, because both showed low intensity. In conclusion, DW-EPI can clearly delineate the white and gray matter of the cervical spinal cord, and this technique will be useful to evaluate white matter disorders such as ischemic or demyelinating disease.

[Delineation of calf deep veins using 2D-TOF MR venography without contrast media: efficacy of tourniquet and leg-warming].

We evaluated the imaging quality of 2D-TOF MR venography of the lower part of the leg and the efficacy of a tourniquet around the knee and leg-warming. In 8 healthy volunteers, MR venography was carried out under the following four conditions: (a) usual MR venography, (b) MR venography with tourniquet around the knee, (c) MR venography after leg-warming and (d) MR venography with tourniquet after leg-warming. Our results suggested that MR venography with tourniquet after leg-warming is best suited for imaging the veins of the leg. We also compared the diagnostic image quality of MR venography and conventional contrast venography in 7 patients with varices. The results showed no significant differences between the two methods. We conclude that MR venography with tourniquet after leg-warming is a technique that provides reliable information about the veins of the leg.

[The usefulness of radiotherapy in the management of intracranial meningioma: a review of 29 patients].

Twenty-nine patients with intracranial meningiomas were treated with a high-energy linear accelerator (4-10 MV. X rays and electron beams) between 1980 and 1992 at the Hiroshima Prefectural Hiroshima Hospital. We investigated the relationships between tumor size and tumor response, histological type and tumor response, and grade of operation using Simpson's classification and recurrence rate. Meningiomas were greatly reduced between 1 month and 46 months after radiotherapy, the average being 14 months. In the group with a tumor size of less than 5 cm2, 3 patients obtained CR, 5 patients NC and 1 patient PD. Tumor response was 89% in the group with a combination of CR with NC. In the group with a tumor size of 5 to 20 cm2, 2 patients obtained PR, 1 patient NC and 1 patient PD. Tumor response was 75% in the group with a combination of PR with NC. In the group with a tumor size of more than 20 cm2, 3 patients showed NC, 3 patients PD. Tumor response was 50% in the group with NC. In the group with a tumor size of less than 20 cm2, tumor response was 85%. In the group with a tumor size of more than 20 cm2, it was 50%. Though there were no statistically significant differences between the two groups, a tumor size of less than 20 cm2 had a tendency to be more responsive than one of more than 20 cm2. The response of meningioma of the transitional type was worse than that of the meningothelial type and fibroblastic type. Fourteen patients after Simpson grade II or III operation were free of recurrence. The results of this study support the role of radiotherapy for meningioma which is less than 20 cm2, and also for treatment after Simpson grade II or III operation.

Insulinoma: correlation of short-TI inversion-recovery (STIR) imaging and histopathologic findings.

We studied the value of short-TI inversion-recovery (STIR) imaging for the localization of pancreatic insulinoma. Four patients (three women and one man aged 35-65 years) with surgically proven insulinoma were included in this study. All patients were examined by MR imaging with spin echo (SE) and STIR sequences. The STIR images were compared with the histopathologic findings in each case. In two patients, the tumors were markedly hyperintense on STIR images, and a 5-mm insulinoma was depicted only by this imaging method in one of the two. In the other two patients, 10-mm insulinomas were only slightly hyperintense on STIR images. The latter tumors had a higher content of collagen fibers than the former, indicating that the amount of collagen influences the signal intensity of insulinoma. Despite some limitations, STIR imaging is a useful noninvasive method for the localization of pancreatic insulinoma.

CT of thrombosed renal vein presenting as a hyperdense mass.

We report a patient with focal renal vein thrombosis that presented as a hyperdense mass mimicking a hyperdense cyst or a pelvic or parenchymal tumor. The lesion was described as a well-defined round hyperdense mass in the right renal sinus on noncontrast CT and was surgically proven to be acute thrombosis of the renal vein. Renal vein thrombosis should be considered in the differential diagnosis of a hyperdense mass in the renal sinus even if the patient has no underlying renal abnormality.

Lymphokine requirement for the generation of natural killer cells from CD34+ hematopoietic progenitor cells.

We have established a cell culture system without stromal cells that allows the CD34+ hematopoietic progenitor cells (HPC) to differentiate into natural killer (NK) cells. CD34+Lin (CD3, CD16, CD56)- cells were purified using fluorescence-activated cell sorting from normal adult bone marrow (BM) and cultured for 28 days in medium supplemented with interleukin-2 (IL-2) and stem cell factor (SCF). NK (CD3-CD16-CD56+) cells were generated in a dose-dependent manner in response to SCF. NK cells originated from CD34+CD33+Lin- cells, but they were barely detectable in cultures of CD34+CD33-Lin- cells. However, on addition of IL-3, an induced differentiation of NK cells from CD34+CD33-Lin- cells was observed, although at a lower frequency. Supplementing of the cell cultures with SCF alone or both SCF and IL-3 for the first 7 days followed by IL-2 for the next 21 days is essential for production of NK cells from CD34+CD33+Lin- cells and from CD34+CD33-Lin- cells, respectively. These data provide direct evidence that NK cells arise from CD34+HPC and show the minimum lymphokine requirement for their differentiation.

Atypical appearance of adrenal pseudocysts.

We report 2 cases of adrenal pseudocysts that resulted from hemorrhage into a normal adrenal gland and that showed atypical imaging features on computerized tomography and ultrasonography. The presence of a solid component within the mass and/or central calcification, which is unlike the typical features of adrenal pseudocyst, suggested a diagnosis of adrenal tumor. The solid component diminished on computerized tomography in 26 days in case 1 and in 16 days in case 2, which seemed to represent resolving hematoma. The atypical appearance of these adrenal pseudocysts, especially the changeable pattern of the solid component within the mass, should be kept in mind to ensure a correct preoperative diagnosis.

Human primitive hematopoietic progenitor cells are more enriched in KITlow cells than in KIThigh cells.

To clarify the phenotypes of various classes of human hematopoietic progenitor cells, we used a multicolor staining protocol in conjunction with CD34 and a newly developed mouse antihuman c-kit proto-oncogene product (KIT) monoclonal antibody (MoAb). We characterized three cell fractions in CD34+ cells that express KITlow and KIThigh cells in addition to KIT- cells. A clonogenic assay showed that most granulocyte-macrophage colony-forming cells (GM-CFC) were present in CD34+KIThigh populations, whereas erythroid burst-forming cells (BFU-E) were detected mainly in the CD34+KITlow population. CD34(+)-KIT- fraction contained a small number of BFU-E. Morphologic analysis showed that blast-like cells were more enriched in the CD34+KITlow fraction. KITlow cells contained CD34+CD38- cells that were considered to be very primitive progenitor cells, as determined by a replating assay. To clarify the biologic differences between both fractions, we examined the more primitive progenitor cell functions by assessing long-term culture-initiating cells (LTC-IC) on the stromal cells. At week 2, more CFC recovered from the culture in the fraction initiated with a CD34+KIThigh population. However, more LTC-IC were present during weeks 5 to 9 in the CD34+KITlow population. These results indicate that primitive progenitors are more enriched in the KITlow population and that the KIThigh population contains many GM-committed progenitor cells. We also showed that anti-KIT MoAb inhibited the ability of CD34+ cells to generate CFC on the stromal layer in the LTC system. This suppressive effect was more evident in the generation of BFU-E by CD34+KITlow cells. Moreover, we confirmed that CD34+KIThigh cells emerged from CD34+KITlow cells during coculture with allogeneic stromal cells or from liquid culture in the presence of stem cell factor (SCF), interleukin-6, and erythropoietin. These results emphasize the pivotal role of the KIT and SCF interaction in hematopoiesis and indicate that KITlow cells are more primitive than KIThigh cells.