Surgical Treatment and Subsequent Outcome of Patients with Carcinoma of the Splenic Flexure

Extended resection, comprising extended right hemicolectomy, splenectomy, and distal pancreatectomy, has been advocated for carcinoma of the splenic flexure because the lymphatic drainage at this site is variable. The present study addresses the problems associated with selecting the most appropriate operative procedure to achieve cure of splenic flexure cancers. We conducted a retrospective review of 27 patients with splenic flexure cancer who under-went curative resection. Left partial colectomy was performed in 20 patients and partial resection of the transverse/descending colon was performed in 7 patients. The combined resection of adjacent organs due to tumor adherence was performed in three patients. The spleen and distal pancreas were the organs most frequently resected among a collective total of six adjacent organs. The median duration of follow-up was 60.9 months after resection for splenic flexure cancer. No patient developed local recurrence. There was no significant difference in 5-year survival between patients with splenic flexure cancers and those with colon cancers at other sites. In conclusion, splenic flexure cancer resected by left partial colectomy or partial resection of the transverse/descending colon without routine extended resection was not associated with a worse prognosis than colon cancers at other sites. Received: February 17, 2000 / Accepted: September 26, 2000     

Survival and sinus rhythm maintenance after modified Cox/maze procedure and mitral valve operation in patients with chronic atrial fibrillation

OBJECTIVE: Sinus rhythm gained after the Cox/maze procedure concomitant with mitral valve operation has demonstrated long-term attrition during the follow-up, no information exists on whether the type of mitral valve operation--(repair vs. replacement)--affects this sinus rhythm maintenance rate. We retrospectively studied patients undergoing concomitant mitral valve operation and Cox/maze procedure to answer this question. METHODS: Between April 1993 and August 1995, 87 consecutive patients--35 men and 52 women (mean age: 59.3 years)--with chronic atrial fibrillation and mitral valve disease underwent the modified Cox/maze procedure and concomitant mitral valve operation, with 56 having mitral valve repair (repair group) and 31 mitral valve replacement (replacement group). Patients were followed up and changes in rhythm studied retrospectively. RESULTS: Follow-up for a mean 51.3 +/- 11.6 months was completed in 82 of 83 long-term survivors (99%). Repair group surgery survival was 98.1 +/- 1.9% at 1 year and 94.2 +/- 3.2% at 5 based on the Kaplan-Meier method. Replacement group surgery survival was 85.7 +/- 5.9% at 1 year and 82.9 +/- 6.4% at 5. Probability in sinus rhythm maintenance for the repair group at 1 year was 88.6 +/- 5.4% and at 5 years was 67.6 +/- 9.1%. Probability in sinus rhythm maintenance for the replacement group at 1 year was 95.7 +/- 4.3% and at 5 years was 65.0 +/- 11.1%. CONCLUSIONS: Medium-term results after the Cox/maze III procedure concomitant with mitral valve operation are good. The attrition of sinus rhythm maintenance appears similar by the completion of 5-year follow-up.     

Spontaneous closure of dural arteriovenous fistula after performing diagnostic angiography

The pathogenesis and clinical treatment of dural arteriovenous fistulas (DAVF) has been well established. However, only 15 cases of spontaneous closure of DAVFs have been reported. We describe a case of spontaneous closure of a DAVF. A 60-year-old male presented with pulsatile tinnitus. Selective cerebral angiography revealed a left posterior DAVF fed by the left occipital artery and the middle meningeal artery, which drained into the left transverse sinus and sigmoid sinus. Following the initial angiography, the patient exhibited vomiting with transient disorientation and amnesia. These symptoms, along with the tinnitus, disappeared by the following day. Seven days after the initial angiography, a second angiography was performed that revealed the complete disappearance of the DAVF. Previous reports have described a long period of closure for DAVFs following initial diagnosis. Possible mechanisms for spontaneous closure of DAVFs include the development of scar tissue or a sinus thrombosis that leads to occlusion of the DAVF In this case, the DAVF closure may have been due to a sinus thrombosis induced by sinus stenosis, since occlusion of the draining sinuses coincided with the spontaneous closure of the DAVF. In cases of non-traumatic DAVF without cortical venous reflex that do not present severe symptoms, a prudent course of treatment is necessary since there is a chance of spontaneous closure of the DAVF occuring.     

Involvement of the programmed death-1/programmed death-1 ligand pathway in CD4+CD25+ regulatory T-cell activity to suppress alloimmune responses

BACKGROUND: Immune regulatory CD4+CD25+ T (regulatory T; Treg) cells play a vital role in the induction and maintenance of self-tolerance. They are essential for the homeostasis of T cells, the prevention of autoimmunity, and the induction of tolerance to allogeneic donor grafts. However, the underlying mechanism of their functions remains mostly elusive. Therefore, we investigated here a crucial role of Treg cells in their response to alloantigen via the programmed death (PD)-1/PD-1 ligand (PD-L1) pathway. METHODS: In vitro mixed lymphocyte reaction (MLR) assay, graft-versus-host disease (GvHD) and a skin transplantation model were used to evaluate the mechanisms of PD-1/PD-L1 pathway. RESULTS: Blockade of the PD-1/PD-L1 pathway using anti-PD-L1 monoclonal antibodies (mAb) is found to inhibit Treg cell's ability to suppress and restore CD4+CD25-T-cell proliferation in vitro. GvHD was lethal after adoptive transfer of allogeneic C57BL/6 (H-2K) spleen cells to NOD/SCID (H-2K) mice unless CD25+ T cells were also included. Strikingly, the suppression of GvHD by CD25+ cells was abrogated by anti-PD-L1 mAb administration. The abrogation of Treg-cell-mediated suppression could also be demonstrated in a Balb/c (H-2K) to B6/Rag-2KO (H-2K) skin-allograft model. CONCLUSIONS: The blockade of the PD-1/PD-L1 pathway abrogates Treg-mediated immunoregulation, thus suggesting that the PD-1/PD-L1 pathway is required for Treg suppression of the alloreactive responses of CD4+CD25-T cells. This finding has important implications for clarifying the mechanisms of allograft rejection and GvHD.     

Long-term outcomes of Gamma Knife surgery for cavernous sinus meningioma

OBJECT: The aim of this study was to evaluate long-term outcomes, including tumor control and neurological function, in patients with cavernous sinus meningiomas treated using Gamma Knife surgery (GKS). METHODS: One hundred fifteen patients with cavernous sinus meningiomas, excluding atypical or malignant meningiomas, were treated with GKS between 1991 and 2003. Forty-nine patients (43%) underwent GKS as the initial treatment. The mean tumor volume was 14 cm3, and the mean maximum and margin doses applied to the tumor were 27 and 13 Gy, respectively. The median follow-up period was 62 months. During the follow-up, 111 patients were able to be evaluated with neuroimaging. RESULTS: The actuarial 5- and 10-year progression-free survival rates were 87 and 73%, respectively. Similarly, the actuarial 5- and 10-year focal tumor control rates were 94 and 92%, respectively. Regarding functional outcomes, 43 patients (46%) experienced some degree of improvement, 40 (43%) remained stable, and 11 (12%) had worse preexisting or newly developed symptoms. Patients who underwent GKS as the initial treatment experienced significant improvement of their symptoms (p = 0.006). CONCLUSIONS: Gamma Knife surgery is a safe and effective treatment over the long term in selected patients with cavernous sinus meningiomas. Tumor progression is more likely to occur from the lesion margin outside the treatment volume. In small to medium-sized tumors, GKS is an excellent alternative to resection, preserving good neurological function. For relatively large-sized tumors, low-dose radiosurgery (< or = 12 Gy) is acceptable for the prevention of tumor progression.     

Trigeminal schwannomas: results of gamma knife surgery in 37 cases

OBJECT: Information on outcomes of Gamma Knife surgery (GKS) for patients harboring trigeminal schwannomas is limited because these tumors are rare. The authors evaluated tumor control and functional outcomes in patients who underwent GKS for trigeminal schwannomas to clarify the efficacy of this treatment. METHODS: Forty-two patients with trigeminal schwannomas but no evidence of neurofibromatosis Type 2 were treated with GKS at Komaki City Hospital between November 1991 and December 2003. Of these, 37 patients were assessed. The mean tumor volume in these patients was 10 cm3. The mean maximum radiation dose directed to the tumor was 27.9 Gy and the mean dose directed to the tumor margin was 14.2 Gy. The mean follow-up period was 54 months. In four patients (11%) there was complete tumor remission; in 20 (54%) there was partial tumor remission; in eight (22%) the disease remained stable; and in five (14%) the tumor enlarged or uncontrollable facial pain developed with radiation-induced edema requiring resection. The actuarial 5- and 10-year tumor control rates were both 84%. With respect to functional outcomes, 40% of patients noted an improvement in their symptoms, and one patient experienced new symptoms despite good tumor control. CONCLUSIONS: Gamma Knife surgery was a safe and effective treatment for a select group of patients harboring trigeminal schwannomas. Large tumors that compress the brainstem and cause deviation of the fourth ventricle should first be removed surgically and any remnant should be treated by GKS.     

Improvement of the survival rate by fetal liver cell transplantation in a mice lethal liver failure model

BACKGROUND: The use of cell transplantation as an alternative therapy for orthotopic liver transplantation has been widely anticipated due to a chronic donor shortage. We previously reported the method used to enrich hepatic progenitor cells (HPCs) forming cell aggregations. In this study, we transplanted HPCs into the liver injury model mice to determine whether HPC transplantation may improve the liver dysfunction. METHODS: We obtained donor cells from E13.5 fetal livers of green fluorescent protein (GFP) transgenic mice. We transplanted GFP-positive fetal liver cells into the transgenic mice which express diphtheria toxin (DT) receptors under the control of an albumin enhancer/promoter. Subsequently, we induced selective liver injury to recipient mice by DT administration. We then evaluated the engraftment of the transplanted cells and their effect on survivorship. RESULTS: The low dose of DT induced sublethal liver injury and the high dose of DT was lethal to the liver injury model mice. The transplanted GFP-positive cells were engrafted into the recipient livers and expressed albumin, resembling mature hepatocytes. They continued to proliferate, forming clusters. The survival rate at 25 days after transplantation of the cell-transplanted group (8 of 20; 40.0%) was improved significantly (P=0.0047) in comparison to that of the sham-operated group (0 of 20; 0%). CONCLUSIONS: The transplanted cells were engrafted and repopulated the liver of recipient mice, resulting in the improvement of the survival rate of the liver injury model mice. We therefore propose that HPCs are a desirable cell source for cell transplantation.     

Informed consent for colorectal cancer surgery

There are two issues in informed consent for colorectal cancer surgery. One is the actual surgical technique. Recently intersphincteric resection (ISR) has been performed to avoid permanent colostomy, although it is not standard procedure. Regarding QOL score, Patients with colostomies do not necessarily have lower quality of life scores than patients who undergo sphincter-preserving surgery because of frequent bowel movements. Lateral lymphadenectomy for lower rectal cancer was standard procedure; however, its indications became limited due to urinary and sexual dysfunction. Preoperative radiotherapy is considered instead of lateral lymphadenectomy, as in the Western concept of the local recurrence of rectal cancer. Now laparoscopic surgery is accepted for stage I colon cancer according to the guidelines of the Japan Society for Cancer of the Colon and Rectum. The other issue is postoperative complications like anastomotic leakage, intestinal obstruction, etc. Frequent bowel movements and urinary and sexual dysfunction should also be explained before rectal cancer surgery.     

Improved survival rate by temperature control at compression sites in rat model of crush syndrome

Background

Crush syndrome (CS) has been reported in disasters, terrorist incidents, and accidents, and the clinical and pathologic picture has gradually been clarified. Few lethal and reproducible animal models of CS with use of a quantitative load are available. A new model is needed to investigate pathologic and therapeutic aspects of this injury.

Materials and methods

Using a device built from commercially available components, both hindlimbs of anesthetized rats were respectively compressed for 6 h using 3.6-kg blocks. The effects of trunk warming alone without compressed hindlimbs (Group A), non-warming at room temperature (Group B), whole-body warming including compressed hindlimbs (Group C), or warming of compressed hindlimbs alone (Group D) during compression were examined. Survival rates were compared and hematological and histologic analyses were performed at specific time points after compression release.

Results

Limb or whole-body warming significantly worsened the survival of rats. We found a much lower survival rate of 0%–10% in animals, in which the hindlimbs were warmed during compression (Groups C and D) at 12 h after compression release, compared with 90%–100% in animals without warming of the hindlimbs (Groups A and B). Groups C and D showed significantly enhanced hyperkalemia at ≥4 h after compression release and all blood samples from dead cases showed hyperkalemia (>10 mEq/L).

Conclusions

We developed a new lethal and reproducible rat CS model with a quantitative load. This study found that warming of compressed limbs worsened the survival rate and significantly enhanced hyperkalemia, apparently leading to cardiac arrest.