Watertight Manner Research Articles

Evaluation and optimization of textile ultrasonic welds for textile temperature control elements using transient thermal numerical analysis

Ultrasonic welding is an efficient method of joining thermoplastic fabrics or other textile semi-finished products in a watertight manner. It is applied in the making of functional clothing, such as chemical protective clothing, sportswear or smart clothing, or other technical products. Another special field of application developed at the Chair of Development and Assembly of Textile Products is the use of coated textiles as temperature control elements. For this type of product, it is necessary to design the ultrasonic welds in such a way that the media-tight coating is not damaged and the joint is continuous. This paper presents the option of evaluating and optimizing the ultrasonic welding process for the production of the textile tempering systems using transient thermal analysis in order to improve the overall quality of the seam and ensure media tightness along the seam.
 In the following article, the status of the welding process, in particular the ultrasonic process, the textile materials, the heating of the textile and the joining process of welding is presented. In addition, the transient heat flow through the textile is investigated with the aid of FEM methods; taking into account, various seam structures.

From the levels of memory to their info-technicist unfolding in the information society

The present article consists of analyzing memory levels from the perspective of Assmann (2008). From a systematic review on the subject, is instituted a vision on the dimension of internal (neuronal), social and cultural memory in the human, material and immaterial relations between groups. A theoretical-analytic dialogue with History, Sociology, Anthropology, Social Psychology, Information Science and other areas of the Social Sciences is undertaken, which are presented not in a watertight manner, but which participate in the analysis of this polysemic object, formed not in the abstraction of the norm, but intertwined with the worlds of people and social dynamics. Next, the level of the cultural dimension of memory is related to the categories of the information society in its triple immersion: as an economic transition, political project and social norms, to discuss the technical dimension of memory whose modern tendency is characterized by the use / use and hyper-industrialization of 'mnemonic technology' for the performance and development of individuals, organizations and societies.

Penetrating Orbitofrontal Foreign Body: Case Report

AbstractOrbitofrontal foreign-body injuries comprise a major cause of all facial injuries referred to a neurosurgeon. The authors hereby present an unusual case of a pressure regulator of a domestic pressure cooker impacted into the orbit and extending through the orbital roof into the basifrontal cortex. The globe was intact externally with no obvious sign of such a large object impacted behind the globe. On imaging, the foreign body was found to have fractured the orbital roof with one end protruding into the basifrontal cortex. A transcranial approach was taken to remove the object with removal of the orbital rim and roof to reach the object. After successful retrieval of the metallic body, all displaced bone fragments were removed and the dural closure was done in a watertight manner. The vision could not be salvaged, most likely due to damage to the optic nerve. However, the globe was left intact and the ocular movements were normal. An important factor to consider in removal of such foreign bodies is that the bone fragments that get impacted should be meticulously removed and the dural tears should be sealed to prevent any intracranial infections and cerebrospinal fluid leaks. Removal of the orbital rim helps in adequate exposure of the retro-orbital space and the basifrontal dura.

A Feature-adaptive Subdivision Method for Real-time 3D Reconstruction of Repeated Topology Surfaces

It's well known that rendering for a large number of triangles with GPU hardware tessellation has made great progress. However, due to the fixed nature of GPU pipeline, many off-line methods that perform well can not meet the on-line requirements. In this paper, an optimized Feature-adaptive subdivision method is proposed, which is more suitable for reconstructing surfaces with repeated cusps or creases. An Octree primitive is established in irregular regions where there are the same sharp vertices or creases, this method can find the neighbor geometry information quickly. Because of having the same topology structure between Octree primitive and feature region, the Octree feature points can match the arbitrary vertices in feature region more precisely. In the meanwhile, the patches is re-encoded in the Octree primitive by using the breadth-first strategy, resulting in a meta-table which allows for real-time reconstruction by GPU hardware tessellation unit. There is only one feature region needed to be calculated under Octree primitive, other regions with the same repeated feature generate their own meta-table directly, the reconstruction time is saved greatly for this step. With regard to the meshes having a large number of repeated topology feature, our algorithm improves the subdivision time by 17.575% and increases the average frame drawing time by 0.2373 ms compared to the traditional FAS (Feature-adaptive Subdivision), at the same time the model can be reconstructed in a watertight manner.

Reconstruction of Chronic Complicated Scalp and Dural Defects Using Acellular Human Dermis and Latissimus Dorsi Myocutaneous Free flap.

We present reconstruction of a complicated scalp-dura defect using acellular human dermis and latissimus dorsi myocutaneous free flap. A 62-year-old female had previously undergone decompressive craniectomy for intracranial hemorrhage. The cranial bone flap was cryopreserved and restored to the original location subsequently, but necessitated removal for a methicillin-resistant Staphylococcal infection. However, the infectious nidus remained in a dermal substitute that was left over the cerebrum. Upon re-exploration, this material was removed, and frank pus was observed in the deep space just over the arachnoid layer. This was carefully irrigated, and the dural defect was closed with acellular dermal matrix in a watertight manner. The remaining scalp defect was covered using a free latissimus dorsi flap with anastomosis between the thoracodorsal and deep temporal arteries. The wound healed well without complications, and the scalp remained intact without any evidence of cerebrospinal fluid leak or continued infection.

Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits

To investigate the VEGF expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits. After partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm) was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. Groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. Sections of 5µm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. To confirm the presence of VEGF in tissues, protein expression was determined by immunohistochemistry. No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. A progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001). VEGF expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001). The latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.

Management of CSF Leak After Vestibular Schwannoma Surgery

To the Editor We have read with great interest the article entitled “Management of Cerebrospinal Fluid Leaks After Vestibular Schwannoma Surgery,” by Mangus et al. (1). We would like to congratulate the authors for their valuable contribution to the relevant literature. Cerebrospinal fluid (CSF) leak is still the most common and challenging complication of vestibular schwannoma surgery, and despite multiple articles suggesting solutions for this problem, it is still a frequent encountered drawback, sometimes at unacceptable high rates. The authors state that postoperative CSF leak rates reported in the literature range from 2% to 30%. Surprisingly, three publications of our group with 0%, 1.4%, and 0.8% CSF leakage are not taken into account (2–4). In this study the authors reported an overall incidence CSF leak of 12.9%. However, if we consider changes in rates over time, we notice that CSF leak rate dropped down from 27% to 6%. We agree with the sentence that this downward trend is consistent with the introduction of abdominal fat graft and modifications in closure techniques, but it would have been worthy to detail the different steps of their closure technique. Indeed, we believe that the main reasons of variation of CSF leak rates in the literature are factors related to surgical technique rather than patient variables. It is stated in this study that authors use fat and muscle grafts for Eustachian tube and middle ear space obliteration in a translabyrinthine approach. Although appealing, muscle graft tends to atrophy, whereas fat graft tends to dissolve on contact with air, which could lead to delayed rhinorrhea. Packing the middle ear cleft with dry periosteum collected at the beginning while drilling the mastoid seems more successful. Up to 1993, the overall incidence of CSF leak in our institution was 6.9%. Given this significant high rate, we decided to modify our closure technique in an attempt to lower its occurrence. In translabyrinthine approach, all air cells should be inspected especially at the level of facial and subfacial recesses, and patent ones must be sealed using bone wax. Next, incus is removed through the aditus, taking care not to dislocate the stapes to avoid CSF leakage through the oval window. Middle ear cleft is then packed with previously collected dry periosteum, which prevents later occurrence of rhinoliquorrhea. At the end, thin and long autologous fat strips are carefully introduced deep in the cerebellopontine angle, and the musculofascial layer is sutured in a watertight manner adding to the seal against leakage. As a result, the incidence dramatically dropped down to less than 1% and still unchanged since (4). Further evidence of the success of this technique is supported by Mamikoglu et al. (5) and Hardy et al. (6) showing a reduction of CSF leak in enlarged traslabyrinthine approach, from 17% to 2.3% and from 13% to 1.6%, respectively (also these 2 last articles have not been cited). The similar concept, by isolating the middle ear from the surgical field, also has been successfully adopted in retrosigmoid approach (7), with an improvement of the CSF rate from 21.4% to 1.8%. Mehdi Ben Ammar, M.D. Department of Neurosurgery Military Hospital of Tunis University of Tunis El Manar Tunisia Paul Merkus, M.D., Ph.D. Department of Otorhinolaryngology-Head and Neck Surgery VU University Medical Center Amsterdam, The Netherlands Filippo Di Lella, M.D., Ph.D. Mario Sanna, M.D. Gruppo Otologico Piacenza Roma, Italy

A Novel Approach for a Complete Laparoscopic Nephroureterectomy with Bladder Cuff Excision

The dilemma in management of the distal ureter and bladder cuff during nephroureterectomy (NU) for transitional-cell carcinoma (TCC) of the upper urinary tract has delayed the development of a completely minimally invasive approach to NU in cases of TCC. Our aim is to present our technique of a purely laparoscopic nephroureterectomy performed entirely through laparoscopic ports, which mimics established principles of open surgical nephroureterectomy with bladder cuff excision. Precluding the needed for patient repositioning, complex endoscopic procedures either before or after nephrectomy and leaving the bladder cuff defect to heal spontaneously. Patient positioning and trocar arrangement are similar to those of radical nephrectomy. The simple addition of a 5 mm trocar in the lower abdomen (midline or lateral to the rectus muscle, according to patient build) allows the surgeon to adequately dissect the distal ureter, excise an adequate bladder cuff, and suture the bladder defect in a watertight manner without the need for transurethral and intraureteral instrumentation as well as intraoperative repositioning of the patient. Eight cases were successfully treated. The operative time ranged from 110 to 200 minutes (mean 157 min). The median time for catheter removal was 7 days; in one patient, catheter removal was delayed to 15 days because of bladder extravasation. Average hospital stay was 10.2 days. During a mean follow-up of 12.1 months, three patients had Ta bladder recurrence, and one patient had local recurrence. A complete NU with bladder cuff excision can be accomplished using this approach, with early results comparable to the gold standard of open surgery with the simple addition of a trocar.

Endoscopic Endonasal Pituitary and Skull Base Surgery

Here we describe the procedures of endoscopic pituitary and skull base surgery in our institute. We also review the literature to reveal recent advances in this field. Endonasal approach via the sphenoid ostium was carried out for pituitary lesions without the nasal speculum. Postoperative nasal packing was basically not needed in such cases. For meningiomas, craniopharyngiomas, and giant pituitary adenomas, which required intra-dural procedures, nasal procedures such as middle nasal conchotomy and posterior ethmoidectomy, and skull base techniques such as optic canal decompression and removal of the planum sphenoidale were carried out to gain a wider operative field. Navigation and ultrasonic Doppler ultrasonography were essential. Angled endoscopes allowed more successful removal of tumors under direct visualization extending into the cavernous sinus and lower clivus. If cerebrospinal fluid (CSF) leakage occurred during operation, the dural opening was covered with a vascularized mucoseptal flap obtained from the nasal septum. Lumbar drainage system to prevent postoperative CSF rhinorrhea was frequently not required. Angled suction tips, single-shaft coagulation tools, and slim and longer holding forceps, all of which were newly designed for endoscopic surgery, were essential for smoother procedures. Endonasal endoscopic pituitary surgery allows less invasive transsphenoidal surgery since no postoperative nasal packing and less dependence on lumbar drainage are needed. Endoscopic pituitary surgery will be more common and become a standard procedure. Endoscopic skull base surgery has enabled more aggressive removal of extrasellar tumors with the aid of nasal and skull base techniques. Postoperative CSF leakage is now under control due to novel methods which have been proposed to close the dural defect in a water-tight manner. Endoscopic skull base surgery is more highly specialized, so needs special techniques and surgical training. Patient selection is also important, which needs collaboration with ear, nose, and throat specialists. As a safe and successful procedure in skull base surgery, this complex procedure should be carried out only in specialized hospitals, which deal with many patients with skull base lesions.

Treatment of Retrocaval Ureter by Pure Laparoscopic Pyelopyelostomy: Experience on 4 Patients

To present our experience and the feasibility of pure laparoscopic pyelopyelostomy for treatment of retrocaval ureter (RCU). RCU was detected in 4 male (ages: 4, 16, 36, 48) patients, with complaints of flank pain. In all the patients, Type 1 RCU was present and the right ureter was involved. All patients underwent intraoperative retrograde pyelography before laparoscopy. The patients were operated upon using the transperitoneal approach in the lateral decubitis position, with two 10 mm and two 5 mm ports. After the ureter was released from the superior and inferior parts of the inferior vena cava, the dilated renal pelvis was transected and the ureter was brought in an anterolateral position to the vena cava. After the completion of the posterior wall anastomosis of pyelopyelostomy with 4-0 polyglactin sutures in a continuous manner, a double-J-stent was placed and the anterior wall was anastomosed in a watertight manner. A drain was placed in the operative area and the operation was completed. Mean operation time was 210 minutes. No intraoperative complications occurred. In one patient, antegrade double-J-stent placement failed, and the stent was therefore placed in the retrograde way without any complications. Postsurgery, the urethral catheter was removed on the first day, and the drain on the second. All patients were discharged 48 hours after surgery. The third month postoperative follow-up confirmed that the anastomoses were patent and patients were symptom-free. Pure laparoscopic pyelopyelostomy seems technically feasible and reliable for RCU treatment. Our experience showed that laparoscopy should be the standard treatment option for such patients.

Use of a latex biomembrane for bladder augmentation in a rabbit model: biocompatibility, clinical and histological outcomes

To investigate histological features and biocompatibility of a latex biomembrane for bladder augmentation using a rabbit model. After a partial cystectomy, a patch of a non-vulcanized latex biomembrane (2x4 cm) was sewn to the bladder with 5/0 monofilament polydioxanone sulfate in a watertight manner. Groups of 5 animals were sacrificed at 15, 45 and 90 days after surgery and the bladder was removed. The 5-mum preparations obtained from grafted area and normal bladder were stained with hematoxylin-eosin. Immunohistochemical staining was performed with a primary antibody against alpha-actin to assess muscle regeneration. No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. Macroscopically, after 90 days, the latex biomembrane was not identifiable and the patch was indistinguishable from normal bladder. A bladder stone was found in one animal (6.6%). On the 90th day, histology revealed continuity of transitional epithelium of host bladder tissue on the patch area. At this time, the muscle layers were well organized in a similar fashion to native bladder muscle layers. The inflammatory process was higher on grafted areas when compared to controls: 15 days--p < 0.0001, 45 days--p < 0.001, and 90 days--p < 0.01. The anti alpha-actin immunoexpression peaked at 45 days, when the graft was observed covered by muscle cells. The latex biomembrane is biocompatible and can be used in models for bladder augmentation in rabbits. It promotes epithelium and muscle regeneration without urinary leakage.

USE OF PORCINE SMALL INTESTINAL SUBMUCOSA IN BLADDER AUGMENTATION IN RABBIT: LONG‐TERM HISTOLOGICAL OUTCOME

To investigate long-term histological features of bladder augmentation using porcine small intestine submucosa (SIS) in a rabbit model. Sixteen New Zealand rabbits were used. Porcine SIS was provided by a manufactured formation derived from the pig. After partial cystectomy was carried out on the bladder, a single layer of SIS (Cook-SIS Technology, Cook Biotech Incorporated, West Lafayette, IN, USA) (2 x 5 cm) was sewn to bladder with continuous 5/0 vicryl suture material in a watertight manner. Urinary diversion was not used. The rabbits were killed 12 months later and perivesical fat was removed together with bladder. The 5-microm preparations taken from the samples were stained with haematoxylin-eosin and Mason's trichrome dye. S-100 and F8 stains were also used for immunohistochemical investigations. The macroscopic view of bladder was normal. SIS was indistinguishable from normal bladder wall, but the region of the graft had a slight white coloration. Microscopic observations showed the continuity of transitional epithelium of host bladder tissue on SIS material. Detrusor and serosal layers were formed and these layers were indistinguishable from host bladder. Fibroblasts were scattered among the collagen fibrils. New vessel formations were present without lymphatic proliferation. Nerve regeneration was excellent. No inflammation was observed in normal and regenerated bladder wall. At the end of 12 months, the long-term histological features of bladder augmentation with porcine SIS in a rabbit model, such as presence of new vessel formations, nerve regeneration, collagen and smooth muscle regenerations, which were indistinguishable from original bladder, and the absence of inflammation, showed that SIS seems to be a viable alternative to the use of intestine in bladder augmentation.

Severe bradycardia and hypotension after connecting negative pressure to the subgaleal drain during craniotomy closure

Negative pressure drainage systems are often used after craniotomy for evacuation of potential bleeding. There are several reports of haemodynamic disturbances with epidural negative pressure drainage, but such reports are very few for subgaleal drains placed over the bone flap. We report a case in which a patient developed severe cardiovascular disturbances after the vacuum drainage was connected to a subgaleal drain after craniotomy for aneurysm clipping. The patient had no significant cardiac history, had an uneventful intra-operative course and yet developed bradycardia and hypotension, which were reproducible and severe enough to require atropine administration. Anaesthetists must be aware of these effects, so that they can anticipate and treat such complications.

Traumatic Leptomeningeal Cyst in a 24-Year-Old Man: Case Report

Traumatic leptomeningeal cysts represent a rare complication of a childhood cranial fracture, and occur in only 0.05 to 0.6% of all cranial fractures. In adults, clinical manifestations of a childhood trauma are very rare and usually appear in the form of nontender, nonpulsatile, subcutaneous mass, accompanied by a progressive neurological deficit and seizures, as shown in our case. We present the case of a 24-year-old man with seizures caused by a traumatic leptomeningeal cyst resulting from the head injury he suffered at the age of 9 months. Right-sided craniotomy was performed with consequent microsurgical removal of the leptomeningeal cyst. The dura was reconstructed in a watertight manner and a cranioplasty was performed with Palacos (Howmedica International, Limerick, Ireland). It is important to consider traumatic leptomeningeal cysts when treating adult patients with erosive bone lesions who have a history of head trauma.

Penile Replantation for A Chinese Tourist Who Had Psychosis

This is a report of a 37‐year‐old tourist who had schizophrenia and self‐mutilation. The complete cut of the lower penile shaft occurred in the early morning. He remained conscious with about 1.5 L blood loss. An emergency replantation was performed after immediate fluid resuscitation. Urethral anastomosis was done in a spatulated fashion through a Foley catheter. Corpus cavernosum were opposed in a watertight manner to secure haemostasis. Tension‐free anastomosis of the dorsal artery, deep dorsal veins, and dorsal penile nerve were performed under the microscope. Penile skin was closed loosely. Warm ischaemic time was 71–2 h after the amputation. Revascularization was satisfactory resulting in a pinkish glans penis. Mild venous congestion was noted at the ventral penile skin without sequel. Full psychosocial support and psychiatric care was commenced after the replantation. He himself pulled out the Foley catheter on day two. Afterwards he remained calm and cooperative. A normal urethrogram, an uroflow test of 18 mL/s, and a return of sharp and blunt sensation over the glans penis were documented two weeks postoperation when he was discharged back to Mainland China. The prognosis of his sexual function was unknown. Either complete resumption of sexual intercourse or second mutilation in psychotic patient had been reported in the literature.

Effect of Intentional Cryo-Injury to the Renal Collecting System.

We determined the short-term and long-term sequelae of intentional cryoablation of the renal pelvicaliceal system and evaluated whether continuous irrigation of the renal pelvicaliceal system with warm saline protects it against cryo-injury. In 12 swine open bilateral renal cryoablation using an argon gas based system was performed to create a cryolesion in the lower pole that was intentionally extended into the collecting system. A single cryoprobe was used to create a 3 cm ice ball in group 1 (6 animals) and 2, 3 mm cryoprobes were used to create a 4.5 cm ice ball in group 2 (6). In all 12 right kidneys pelvicaliceal warming (range 38C to 42C) was performed using continuous retrograde saline irrigation through an indwelling 5Fr ureteral catheter. In all 12 left kidneys cryoablation was performed without pelvicaliceal warming. Real-time confirmation of caliceal involvement by the cryolesion was obtained by retrograde ureteropyelogram. Immediately after cryo-injury 6 left and 6 right kidneys were harvested for histology and the animals with a solitary kidney were followed for 1 to 3 months. Nadir cryoprobe tip temperature was -136C with a mean cryolesion time of 10.5 minutes. Cryolesion size was comparable in the right vs left kidneys in groups 1 and 2 (2.9 vs 3.0 and 4.7 vs 4.6 cm, respectively). Similarly cryoablation time was comparable between the right and left kidneys in groups 1 and 2 (11.3 vs 10.8 and 11.9 vs 12.2 minutes, respectively). Two animals died of aspiration pneumonia (1) and wound dehiscence (1). In all 10 surviving animals no instance of urinary extravasation was noted. At 1-month followup regrowth of normal urothelium occurred with some scarring of the lamina propria or underlying smooth muscle. Adjacent renal parenchyma was replaced by fibrous scar. At 3 months the cryo-injured collecting system was completely healed with a fibrous scar. There were no appreciable histological differences between the kidneys with or without warm pelvicaliceal irrigation. Our data suggest that absent physical puncture injury of the collecting system with the cryoprobe tip the cryodamaged renal collecting system heals by secondary intention in a watertight manner. These data have clinical relevance for facilitating cryoablation of a small, localized, central renal tumor in proximity to the pelvicaliceal system.

Laparoscopic partial nephrectomy with suture repair of the pelvicaliceal system

Objectives Laparoscopic partial nephrectomy is emerging as a viable minimally invasive nephron-sparing option for select patients with an exophytic renal tumor. With increasing experience, we are applying laparoscopic partial nephrectomy to tumors invading more deeply into the renal parenchyma, necessitating intentional caliceal entry to ensure an adequate margin of resection. In this prospective study, we assessed the safety and efficacy of such substantive renal parenchymal resections that incorporate laparoscopic suture repair of the collecting system. Methods Since August 1999, laparoscopic partial nephrectomy was performed in 64 patients with a renal tumor. Our technique routinely involved transient clamping of the renal artery and vein, caliceal suture repair (if necessary), and renal parenchymal suture repair. Intraoperative and postoperative data from the group requiring caliceal repair (group 1, n = 27) were compared with those not requiring caliceal repair (group 2, n = 37). The mean tumor size was 3.4 ± 1.6 cm in group 1 and 2.6 ± 0.9 cm in group 2 ( P = 0.02). The mean depth of tumor invasion into the renal parenchyma was 1.5 ± 0.8 cm in group 1 and 0.9 ± 0.3 cm in group 2 ( P = 0.15). Results Laparoscopic partial nephrectomy was technically successful in all 64 cases without any open conversions. Both groups 1 and 2 were comparable in terms of total operative time (3.2 ± 0.9 hours versus 2.7 ± 1.0 hours, P = 0.06), tumor excision time (5.9 ± 1.8 minutes versus 6.0 ± 1.9 minutes, P = 0.97), and estimated blood loss (241 ± 306 mL versus 258 ± 342 mL, P = 0.27). Pelvicaliceal suture repair was associated with a longer warm ischemia time (30.2 ± 5.4 minutes versus 19.4 ± 4.9 minutes, P <0.0001), and a greater hospital stay (3.0 ± 1.7 days versus 1.8 ± 1.2 days, P = 0.003). No patients in group 1, and 1 patient in group 2, developed an asymptomatic perinephric urinoma that was drained percutaneously. On pathologic examination, inked surgical margins were negative for cancer in all but 1 case; the width of the parenchymal margin on histologic examination was 0.5 ± 0.4 cm in group 1, and 0.4 ± 0.3 cm in group 2 ( P = 0.59). The mean preoperative and postoperative serum creatinine was 1.1 and 1.2 mg/dL in group 1 and 1.0 and 1.1 mg/dL in group 2, respectively ( P = 0.4). During a mean follow-up of 9.5 ± 3.5 months in group 1 and 15.7 ± 4 months in group 2, no renal unit developed irreversible ischemic damage or local cancer recurrence. Conclusions Laparoscopic partial nephrectomy can be performed safely and efficaciously for select invasive renal tumors with intrarenal extension, even up to the collecting system. Intentional caliceal entry in such cases can be effectively repaired in a watertight manner by laparoscopic freehand suturing, albeit with longer mean operative and warm ischemia times, without adverse renal functional sequelae.

LAPAROSCOPIC PARTIAL NEPHRECTOMY FOR RENAL TUMOR: DUPLICATING OPEN SURGICAL TECHNIQUES

We describe our technique of and single institutional experience with purely laparoscopic partial nephrectomy for renal tumor, wherein the focus is to duplicate established open techniques of oncologic nephron sparing surgery. Since August 1999 laparoscopic partial nephrectomy for renal tumor has been performed in 50 patients. Of the patients 24 (48%) had either a compromised contralateral kidney (20) or a solitary kidney (4). Mean tumor size was 3.0 cm. (range 1.4 to 7). In 9 patients (18%) the inner margin of the tumor was in close proximity to the pelvicaliceal system. Our current laparoscopic technique involves preoperative ureteral catheterization, laparoscopic renal ultrasonography, transient atraumatic clamping of the renal artery and vein, tumor excision with an approximate 0.5 cm. margin using cold endoshears and/or J-hook electrocautery, pelvicaliceal suture repair (if necessary) and suture repair of the renal parenchymal defect over surgicel bolsters. In 1 case renal surface hypothermia was achieved laparoscopically with ice slush. All suturing and knot tying were performed with free hand intracorporeal laparoscopic techniques exclusively. All procedures were successfully completed without open conversion. Mean surgical time was 3.0 hours (range, 0.75 to 5.8) and mean blood loss was 270.4 cc (range 40 to 1,500). Mean warm ischemia time was 23 minutes (range, 9.8 to 40). Caliceal entry in 18 cases (36%) was suture repaired in a watertight manner. Following caliceal repair, none of these 18 patients had a postoperative urine leak. Hospital stay averaged 2.2 days (range 1 to 9). Major complications occurred in 3 patients (6%) including intraoperative hemorrhage in 1, delayed hemorrhage necessitating nephrectomy in 1 and urine leak in 1. Renal cell carcinoma was confirmed on pathological examination in 34 patients (68%), and all had negative inked surgical margins for cancer. During a mean followup of 7.2 months (range 1 to 17) no patient has had local or port site recurrence or metastatic disease. Laparoscopic partial nephrectomy is a viable alternative for select patients with a renal tumor. The largest single institutional experience to date is presented wherein the open techniques of nephron sparing surgery have been duplicated laparoscopically.

Device capable of being submerged and including an acoustic transducer

A case (2) in which an acoustic transducer (22) is mounted so as to communicate in a watertight manner with the exterior of the case (2) via acoustic energy. The transducer (22) is attached to a membrane (17) separating it in a watertight manner from an inlet cavity (10, 11) which is arranged in the case (2) and is in direct communication with the exterior. The membrane (17) is resiliently applied by its periphery onto a rest surface (12) arranged around the cavity separating the latter in a watertight manner from a deformation chamber (13) situated on the side of the membrane (17) opposite to the inlet cavity while being in communication with the interior of the case. The bottom (13a) of the deformation chamber (13) forms a support surface for said membrane (17) when external static pressure greater than a predetermined value is applied thereto.

Iatrogenic lumbar meningocoele: report of three cases.

We have reported three cases of iatrogenic lumbar meningocoeles after surgery for herniated lumbar intervertebral discs. We reject the term spurious, pseudo, or false as given by earlier writers. We feel that, in reality, these sacs are true meningocoeles, with complete arachnoidal lining and freely communicating with the intraspinal subarachnoid space. We have also given a brief outline of the clinical features, elucidated the mechanisms operative in the production of symptoms, and suggested the cardinal features of radiographic diagnosis. Prevention is, of course, the best way to avoid this complication. If a dural tear does occur, every effort should be made to suture it in a watertight manner.