Mesoappendix as potential donor site for vascularized lymph node transfer: anatomic study.

BACKGROUND: The standard of care for treatment of lymphedema is manual lymphatic drainage and compression therapy, which is time intensive and requires a life-long commitment. Autologous lymph node transfer is a microsurgical treatment in which a vascularized lymph node flap is harvested with its blood supply and transferred to the lymphedematous region to assist with lymph fluid clearance. An ideal donor lymph node site minimizes the risk of iatrogenic lymphedema and other donor site morbidity. To address this, we have used jejunal mesentery lymph nodes and omental flaps and hypothesize that the mesoappendix, as a "spare part," may be an ideal autologous lymph node transfer donor site. METHODS: In this Institutional Review Board-approved study, 25 mesoappendix pathology specimens resected for benign disease underwent gross pathologic examination for the presence of lymph nodes and measurement of the appendicular artery and vein caliber and length. RESULTS: A single lymph node was present in two of 25 specimens (8%). Mean arterial and vein calibers at the point of ligation were 0.87 ± 0.44 mm and 0.86 ± 0.48 mm (range 0.30-2.2 mm and 0.25-2.2 mm), respectively. Mean arterial and vein length was 1.70 ± 1.06 cm and 1.84 ± 1.09 cm (range 0.8-4.5 cm for each), respectively. CONCLUSIONS: The mesoappendix rarely contains a lymph node. The artery and vein calibers of 46% of the specimens were greater than 0.8 mm, the minimum caliber preferred for microsurgical anastomosis. If transplantation of a vascularized lymph node for the treatment of lymphedema is desired, the mesoappendix is inconsistent in providing adequate lymph nodes.

Alternative ileal flap for bladder augmentation if mesentery is short.

PURPOSE: To date the clam ileocystoplasty is the preferred method of bladder augmentation in children when the urodynamic problem is non-compliance and/or detrusor overactivity. The key to this technique is the incision of the bladder wall deep into the pelvis down to the trigone in order to avoid a diverticulum like neobladder and to provide adequate margin for augmentation. The detubularised ileum flap therefore has to reach to the bottom of the divided bladder on a reliable vascular pedicle without significant tension. A short ileal mesentery caused by previous surgery, peritonitis, peritoneal dialysis or ventriculo-peritoneal shunt may complicate surgery and compromise outcome. We hypothesized we can rely on the communication of the intramural vessels within the intestine and can detubularise the ileum adjacent to the mesentery rather than along the antimesenteric line and this could be combined with ligation of some vasa recta (VR) in order to create alternative ileum flaps, which reach further into the pelvis. Our aim was to assess the viability of the alternative flaps detubularised along the paramesenteric line and measure how many VR could be sacrificed beyond the tertiary arcades. MATERIALS AND METHODS: After ethical approval adjacent ileal segments were detubulirased along the antimesenteric line (Group 1) and along the paramesenteric line (Group 2) in 5 minipigs in general anaesthesia. Ligation of 0,1,2,3 and 4 VR has been performed starting from the free end of the segments. The length of the ileal flaps was recorded. The microcirculation of flap edges was detected by in vivo microscopy using orthogonal polarising spectral imaging (Cytoscan A/R Cytometrics, PA, USA). Clam ileocystoplasty was performed with the ileum detubularised along the paramesenteric line without ligation of VR. Specimens of the augmented bladder were obtained after 4 weeks and stained with Hematoxilin + Eosin. RESULTS: No alteration in capillary red blood cell velocity (RBCV) and perfusion rate (PR) was observed after paramesenteric detubularisation. The flaps in Group 2 reached 20.25 ± 0.5 mm longer vs. CONTROL: This is 98% of the mean bowel width (20.5 ± 0.57 mm) measured in the animals. Ligation of each VR further increased the length of both flaps (mean: 10.59 ± 3.18 mm) however ligation of more than 2 VR gradually decreased the microcirculation in both groups. All animals augmented with alternative flap survived, there was no urine leak or suture break down. Histology confirmed viable bowel flaps. CONCLUSION: Paramesenteric detubularisation of the ileum is fully tolerated and results in longer reaching ileal flap vs. CONTROL: Only limited ligation of VR is tolerated. DISCUSSION: This study showed the first time that clam ileocystoplasty is feasible with ileal flap detubularised along the paramesenteric line. The use of the animal model and the relative short postoperative observation are the main limitations of this study.

The fetal porcine aorta and mesenteric acellular matrix as small-caliber tissue engineering vessels and microvasculature scaffold.

BACKGROUND: The extracellular matrix (ECM) is characterized by not only well-preserved scaffolds of organs and vascularized tissues, but also by extremely low immunogenicity during allo- or xeno-implantation. This study aimed to establish a model of a composite microvasculature network scaffold with a small-caliber-dominant vascular pedicle by decellularizing fetal porcine aorta and the conterminous mesentery. METHODS: The aorta and the conterminous mesenteric vascular system originating from the inferior mesenteric artery were harvested from fetal pigs at late gestation. All of the cellular components were removed by sequential treatment with Triton X-100 and sodium dodecyl sulfate. After the degree of decellularization was assessed, the fetal porcine aorta and mesenteric acellular matrix (FPAMAM) were transplanted into dogs. RESULTS: Gross and histologic examination demonstrated the removal of cellular constituents with preservation of ECM architecture, including macrochannels and microchannels. The residual DNA content in the FPAMAM was less than 2 %. The aorta and microchannels were perfused well, and the fetal porcine aorta had good patency for more than 3 months. CONCLUSIONS: The integrity of the FPAMAM provided a scaffold for the reconstruction of a rich vascular network with numerous segmentally radiating branches. Decellularized fetal porcine vascular tissue might be a potential alternative for xenogeneic transplantation based on its optimized properties and low immunogenicity. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Aorto-mesenteric and renal allograft transplant: a novel treatment for midaortic syndrome.

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the aorta and often involving renal and visceral arteries. Current therapies include medical management of associated hypertension, and interventional procedures such as angioplasty or surgical bypass. We report a 2-year-old female with severe MAS who was initially treated with angioplasty and stents in both her aorta and superior mesenteric artery (SMA). Due to the presence of long segment stenoses, her renal arteries were not amenable to surgical reconstruction and she rapidly progressed to Stage V chronic kidney disease. The patient underwent bilateral nephrectomy and renal transplantation using a donor thoracoabdominal aorta allograft to provide inflow for the kidney as well as to bypass the nearly occluded aorta. The donor SMA was used to bypass the native SMA stenosis. Postoperatively, the patient had normalization of four limb blood pressures. She weaned from five anti-hypertensive agents to monotherapy with excellent renal function. This is the first reported case of thoracoabdominal aortic bypass using allograft aorta to address MAS. This approach allowed for successful kidney transplantation with revascularization of the mesenteric, and distal aortic circulation using allograft conduit that will grow with the child, obviating the need for repeated interventional or surgical procedures.

Lymphadenopathy in the mesenteric pedicle of the free jejunal flap: reactive lymphadenopathy, not metastatic.

OBJECTIVE: Reconstructive surgery using the free jejunal flap is sometimes performed to close surgical defects in patients undergoing pharyngolaryngectomy for laryngeal or hypopharyngeal cancer. The clinical significance of lymph nodes in the flap was retrospectively examined. METHODS: Fifteen patients had undergone a laryngectomy with free jejunal flap reconstruction between March 1996 and October 1999. The appearance and size of lymph nodes of the flap were examined by 3 radiologists. RESULTS: Lymph nodes were observed in 10 patients. Size increases were noted within 1 year after surgery but not beyond 1 year. The pathologic diagnosis of the excised nodes was reactive lymphadenopathy. CONCLUSIONS: Lymph nodes may occasionally become apparent in the free jejunal flap. There was no suggestion of metastatic lymph nodes when examined retrospectively. We speculate that this reaction was the result of environmental changes attributable to surgery.

Bilateral Jejuno-mesenteric flap for reconstruction of complicated pharyngoesophageal defect.

The surgical management of an infectious and fistulous wound with a pharyngoesophageal tumor is one of the greatest challenges for head and neck and plastic surgeons. The free jejunal transfer has been the standard technique for pharyngoesophageal reconstruction, and the free omental flap has been one of the most reliable methods for reconstructing contaminated wounds. A jejuno-mesenteric flap is suitable for such complicated wounds. Pharyngoesophageal defects are reconstructed by the jejunum, and contaminated and heavily irradiated neck wounds are covered with the mesenteric flaps connected with a revascularized jejunum. The technique described here possesses the advantages of both a free jejunal flap and an omentum flap. Therefore, it is a reliable method for reconstructing the pharyngoesophageal defects of complicated wounds.

Pelvic floor reconstruction after major cancer surgery.

BACKGROUND: Many surgical techniques to keep the small intestine out of the pelvis after cancer surgery have been developed. METHODS: We used part of the ileum and its mesentery sutured around the linea terminalis in ten patients who underwent surgery for rectal or gynecologic carcinomas. RESULTS: All imaging studies of our patients on the tenth postoperative day confirmed the position of the bowel above the pelvis. Four of ten patients had radiation treatment postoperatively without any problems. CONCLUSION: Use of the ileum to reconstruct the pelvic floor seems to be a simple and efficacious technique to keep the pelvic area free. We believe this warrants further investigation in a larger number of patients.

Free vascularized mesentery transfer for closure of wide peritoneal wall defects.

The repair of large abdominal defects can often present problems related to the availability of local tissues adequate for filling the gap without creating high abdominal tension and pressure. The use of a free vascularized mesentery flap for restoration of the abdominal wall, in a case of an infiltrating carcinoid of the right upper and middle abdomen, is reported. After anastomosing the mesentery donor vessels to the deep inferior epigastric artery and vein, the subcutaneous and cutaneous layers were sutured primarily. Closure of the peritoneal cavity by means of vascularized undamaged visceral peritoneum should avoid infection and the formation of adhesions.

Mesenteric fibromatosis preventing restorative proctectomy.

A case is reported illustrating the dilemma of encountering mesenteric fibromatosis during restorative proctectomy for familial adenomatous polyposis.

The effect of fibrin glue and peritoneal grafts in the prevention of intraperitoneal adhesions.

We studied the effect of fibrin sealant and peritoneal grafts applied by fibrin glue on adhesion formation in the rat. Sealing and patching of ischaemic lesions of the uterus resulted in a significant increase in adhesion formation. We conclude, that fibrin sealant and peritoneal grafts can not be given general approval for prophylaxis of intraperitoneal adhesions.

[Structural changes in popliteal lymph nodes in the graft vs. host reaction to H-Y antigen in male C57BL/6-strain mice]. / Strukturnye izmeneniia v podkolennom limfaticheskom uzle pri reaktsii "transplantat protiv khoziana" na H-Y-antigen u samtsov myshei linii C57BL/6.

Regional popliteal lymph nodes in intact, control and experimental (I, II, III groups, respectively) have been studied by means of the morphometric method in male C57Bl/6 line mice at the pick of the reaction produced by injection of spleen cells and mesenteric lymph nodes obtained from syngenic females and repeatedly immunized to H-Y antigen (10 animals in each group). Injection of the cell suspensions from the immunized and intact females of the C57Bl/6 mice result nearly in two-fold increasing mass of the regional popliteal node at the expense of enlarged size of all its zones. Changes in cytoarchitectonics of the node structural components result from redistribution of certain cellular elements. The essential changes in the cell composition of the lymph nodes in the II and III male groups are accompanied with an increasing part of the stromal reticular cells. Simultaneously, content of small lymphocytes decreases significantly. In the III group of mice there is a sharp increase in the content of young forms of the lymphoid line cells in all structural components of the node, as well as in eosinophilic granulocytes in medullary cords. In the dark cortical zone of the nodes (III group) there occur tissue basophils (mast cells), that, together with increasing number of acidophilic granulocytes and appearance of neutrophilic cells, demonstrates that there is an inflammatory reaction in the organ studied as a response to the lymphocytic suspension injected. In the experimental group of the animals a complete disappearance of plasma cells is noted in the node cortex, but some increase of their part takes place in the medullary cords.

Morphology and fibrinolytic activity of canine autogenous mesothelium used as venous substitute.

Autogenous mesothelium was used as venous substitute in ten dogs. Patches of mesothelium of three different origins were grafted into the anterior wall of the common iliac veins (CIV): peritoneum taken from and including the posterior rectus sheath (PRS), simple peritoneum (P) and mesentery (M). Animals were killed after 2, 4, 8, and 16 days and after 3 months. The segments of CIV, including the patches, were removed for study. On light microscopy, the PRS grafts showed a normal mesothelium but marked submesothelial fibrosis. The M and P grafts showed normal mesothelium and only mild fibrous thickening. On scanning electron microscopy, there was a perfect continuity of the mesothelial cells and the normal endothelium at the suture line. In the center of the graft, the cells had become elongated along the axis of blood flow. Fibrinolytic activity (FA) was measured by a standardized fibrin plate technique and quantitated in tissue activator units per gram of tissue (TAU/g). The mean FA of iliac vein specimens was 1101.7 +/- 133.3 TAU/g (mean +/- SEM). The mean FA determined before grafting for each kind of mesothelium was the following: PRS = 418.8 +/- 26.9 TAU/g; P = 873.0 +/- 107.1 TAU/g; M = 1142.3 +/- 91.4 TAU/g where only PRS showed values significantly lower than iliac vein mean FA (P less than 0.001). Postoperatively, the mesothelial FA, after an initial reduction, increased on day 4 and reached values significantly higher than the control values (1445.7 +/- 204.1 TAU/g tissue vs 853.1 +/- 62.3 TAU/g tissue; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

A gut and mesentery pedicle for bridging lymphatic obstruction: experimental studies.

Experiments have been carried out in the pig. Small bowel and its mesentery are rich in lymphatics. A pedicle of ileum (opened and denuded of its mucosa) and its mesentery has been used to bypass lymphatic obstruction. Diversion of lymphatic drainage from the lower limb into the lymphatics of the bridge has been demonstrated lymphographically in the living animals and also by post mortem injection studies.

[Neurotrophic interaction of spinal cord ganglia with different tissues]. / Neirotroficheskoe vzaimodeistvie spinnomozgovykh gangliev s razlichnymi tkaniami

Spinal ganglia L5-L6 together with mesocolon (innervated from these ganlia) and tongue epithelium were transplanted into the anterior chamber of the cat eye. In 2 months survival of some of the sensory neurons and intensive regeneration of their nerve fibers was observed. At the same time the mesocolon tissues with the mechanoreceptors (Pacinian corpuscles) were found to survive. Destruction of the tongue epithelium was revealed. The trophic effect of definite sensory ganglia on the tissue corresponding to them provided structural intactness of this tissue and of its receptor apparatus. It is suggested that the metabolic conformity of the tissue and the source of its innervation is necessary for the tissue survival.