Splenic pseudocysts. Apropos of a case

The authors report a case of pseudocyst of the spleen. This is a rare entity which is part of nosological type of nonparasitic splenic cysts. It has most often a post-traumatic origin. The diagnosis is evoked in front of a mass of the left hypochondrium and has to be confirmed by further examinations, in particular by sonography and scanner. A microscopic examination of the surgical specimen is the only way to establish the diagnosis of a pseudocyst. The histological characteristic of pseudocyst is absence of epithelium. The splenic pseudocysts require a surgical treatment. In most cases, a splenectomy is performed. A the moment, cyst resection and partial splenectomies are performed by a few authors. This is the type of technique that we prefer especially when the patient is young.     

Insertion of a chest tube to drain pneumothorax

Intercostal chest tube drainage with an underwater seal is a simple and effective method to eliminate air in the pleural space. The patient is then positioned lying, shoulder elevated and undressed to the waist, with the arm abducted at 90°. The fourth intercostal space just anterior to the mid-axillary line is usually chosen. The surgical field is prepared with antiseptic solution, and lidocaine is injected to create a transverse wheal to demarcate the length and position of the skin incision. The tip of the scalpel blade is used to make an incision large enough to comfortably admit the index finger. Blunt dissection is undertaken using a Roberts clamp. Once the deep fascia is reached, the intercostal space becomes distinctive. Further lidocaine is used to create a field block by injecting multiple intercostal nerves. After leaving adequate time for the intercostal block to work, the Roberts clamp is then used with gentle but firm pressure spreading the intercostal muscles apart. When the Roberts clamp enters the pleural cavity, a gush of air is normally audible. The jaw of the Roberts clamp is opened to dilate the puncture site, and then followed by the index finger to dilate a tract into the pleural space. Once satisfied that there is no lung tissue adhering to the chest wall, a 28 French gauge drain is introduced into the pleural space without a trocar. Once the drain is sited, it is attached to an underwater seal, and the drain is then secured with a silk suture.     

Chaotic dynamics and convergence analysis of temporal difference algorithms with bang‐bang control

Reinforcement learning is a powerful tool used to obtain optimal control solutions for complex and difficult sequential decision making problems where only a minimal amount of a priori knowledge exists about the system dynamics. As such, it has also been used as a model of cognitive learning in humans and applied to systems, such as humanoid robots, to study embodied cognition. In this paper, a different approach is taken where a simple test problem is used to investigate issues associated with the value function's representation and parametric convergence. In particular, the terminal convergence problem is analyzed with a known optimal control policy where the aim is to accurately learn the value function. For certain initial conditions, the value function is explicitly calculated and it is shown to have a polynomial form. It is parameterized by terms that are functions of the unknown plant's parameters and the value function's discount factor, and their convergence properties are analyzed. It is shown that the temporal difference error introduces a null space associated with the finite horizon basis function during the experiment. The learning problem is only non‐singular when the experiment termination is handled correctly and a number of (equivalent) solutions are described. Finally, it is demonstrated that, in general, the test problem's dynamics are chaotic for random initial states and this causes digital offset in the value function learning. The offset is calculated, and a dead zone is defined to switch off learning in the chaotic region. Copyright © 2015 John Wiley & Sons, Ltd.     

A new technique for intracorporeal knot tying in laparoscopic surgery

INTRODUCTION: Laparoscopic intracorporeal knot tying in minimally invasive surgery is an advanced skill. Mastering this skill is a difficult process with a long learning curve. Intracorporeal suturing is essential to advanced laparoscopy and is a rate-limiting step in many procedures. Many different instruments and methods have been described for laparoscopic suturing and knot tying. We have developed a new technique for laparoscopic knot tying. TECHNIQUE: The long end of the suture is held with a left-hand instrument, and the instrument is rotated for 360 degrees in a clockwise direction to make a forward-direction loop. The end of the loop is grasped with the right-hand instrument, and the other end of the suture is grasped with the left-hand instrument. The suture end, held by the left hand, is pulled though the loop and tied, thus making a half-knot of a square knot. The second half-knot is made by using the right-hand instrument with the same technique. DISCUSSION: Laparoscopic suturing and knotting is difficult to perform, especially when the angle between the working instruments is narrow and working space is limited. In all these situations, knot tying using this technique makes knotting more simple and easy to perform, especially for those who have limited experience in intracorporeal suturing and knot tying. No special instrument is required to perform knot tying with this technique.     

Fever in intensive care: an open problem

Fever is one of the most aspecific marker of disease, it is considered a protective host defense response and it is the result of a reset of the hypothalamic thermostat. Fever is a common problem in ICU patients and it is associated with infective and non infective causes. Fever presenting in ICU should always be a source of concern and the first and immediate priority is to determine its clinical significance.     

腹股沟疝与精索脂肪瘤

精索脂肪瘤是腹膜外脂肪经腹股沟内环突出形成的真性脂肪瘤.发生率一般在20%～30%.常由腹膜外脂肪从深环中脱出延续而造成,分叶状的后腹膜脂肪进入深环使其扩张,从而导致腹股沟疝与精索脂肪瘤的形成.BMI越高精索脂肪瘤越容易发生.同时也发现精索脂肪瘤在Ny-bus Type Ⅱ及Ⅲb型的患者存在更高的发生率,说明了精索脂肪瘤的发生与疝的类型有关系,疝越大越容易发生.精索脂肪瘤的术前诊断不易,其临床表现与腹股沟疝及其相似.超声检查是一种安全而有效的方法,对诊断腹股沟疝和脂肪瘤的确诊率高达92%.只要腹膜外脂肪组织疝入腹股沟管,在手术中尽可能的将脂肪瘤切除,并按腹股沟疝行修复手术.     

Laparoscopy-assisted hepatectomy using the Endoclose: a case report

Hemostasis of a resected stump of liver is extremely difficult in laparoscopic hepatectomy. Although Pringle's maneuver, which is a total clamping of the hepatoduodenal ligament, is a useful technique, it is often difficult in laparoscopic circumstances. Moreover, total inflow occlusion leads to postoperative liver damage. Therefore, the local bleeding method is ideal. The Endoclose, a device for port site closure, is formed from an outer sheath and an inner needle with a notch to load the suture. The Endoclose is loaded with a suture and passed through the liver. The suture is left under the liver, and the device is removed. Next, the suture carrier is passed through the liver at an appropriate distance, and the suture is regrasped by this suture carrier and brought out of the liver. Herein we report a case in which a new bleeding control method using Endoclose was introduced for laparoscopy-assisted hepatectomy.     

Micro-tourniquet method: a substitute or supporting technique for aneurysm clipping

The micro-tourniquet method is designed as a substitute and/or supporting technique for obliterating aneurysms that are difficult to operate on using the conventional clipping technique. This method is useful for squeezing the aneurysm neck and making a detour around the neck to spare the branching vessels. These micro-tourniquet instruments are a ligature with both ends attached to a ligature guide, a guide holder, a silastic sheath, and a hemostatic clip or a small aneurysm clip set. The ligature is a 20cm long GORE-TEX suture CV-3, and is attached on both ends to a ligature guide. These ligature guides are made of 7mm wire, and are malleable enough to be bent intentionally during surgery. However, they are also rigid enough to be used as a micro dissector. The silastic sheath is made of a 20G infusion needle, and is cut to a length of 2cm. After branching vessels and perforators are dissected and spared with the aid of the ligature guide, the ligature is passed around the aneurysm neck, both ends of the ligature are passed through the sheath, the aneurysm neck is squeezed, and a clip is applied as a stopper on the ligatures adjacent to the distal end of the sheath. By gently displacing the distal end of the sheath, a conventional aneurysm clip is applied on the aneurysm neck just distal or proximal to the ligature on the neck. Then, the ligature is removed. Two demonstrable cases are presented and the usefulness of the micro-tourniquet method is discussed.     

A Full Eulerian Fluid-Membrane Coupling Method with a Smoothed Volume-of-Fluid Approach

A novel full Eulerian fluid-elastic membrane coupling method on the fixed Cartesian coordinate mesh is proposed within the framework of the volume-of-fluid approach. The present method is based on a full Eulerian fluid-(bulk) structure coupling solver (Sugiyama et al., J. Comput. Phys., 230 (2011) 596–627), with the bulk structure replaced by elastic membranes. In this study, a closed membrane is considered, and it is described by a volume-of-fluid or volume-fraction information generally called VOF function. A smoothed indicator (or characteristic) function is introduced as a phase indicator which results in a smoothed VOF function. This smoothed VOF function uses a smoothed delta function, and it enables a membrane singular force to be incorporated into a mixture momentum equation. In order to deal with a membrane deformation on the Eulerian mesh, a deformation tensor is introduced and updated within a compactly supported region near the interface. Both the neo-Hookean and the Skalak models are employed in the numerical simulations. A smoothed (and less dissipative) interface capturing method is employed for the advection of the VOF function and the quantities defined on the membrane. The stability restriction due to membrane stiffness is relaxed by using a quasi-implicit approach. The present method is validated by using the spherical membrane deformation problems, and is applied to a pressure-driven flow with the biconcave membrane capsules (red blood cells).     

Insertion of a chest tube to drain pneumothorax

Intercostal chest tube drainage with an underwater seal is a simple and effective method to eliminate air in the pleural space. The patient is then positioned lying, shoulder elevated and undressed to the waist with the arm abducted at 90°. The fourth intercostal space just anterior to the midaxillary line is usually chosen. The surgical field is prepared with antiseptic solution, and lidocaine is injected to create a transverse wheal to demarcate the length and position of the skin incision. The tip of the scalpel blade is used to make an incision large enough to admit the index finger comfortably. Blunt dissection is undertaken using a Roberts clamp. Once the deep fascia is reached, the intercostals space becomes distinctive. Further lidocaine is used to create a field block by injecting multiple intercostal nerves. After leaving adequate time for the intercostal block to work, the Roberts clamp is then used with gentle but firm pressure, spreading the intercostals muscles apart. When the Roberts clamp enters the pleural cavity, a gush of air is normally audible. The jaw of the Roberts is opened to dilate the puncture site, and then followed by the index finger to dilate a tract into the pleural space. Once satisfied that there is no adherent lung tissue to the chest wall, a 28 F drain is introduced into the pleural space without a trocar. Once the drain is sited, it is attached to an underwater seal, and the drain is then secured with a silk suture.     

Giant retroperitoneal liposarcoma

Liposarcoma is a malignant tumor that has an embryologic origin from mesodermal tissue depending on fatty tissue. Although liposarcoma is only 0.1% of all human neoplasms, it is the most common histology subtype of retroperitoneal soft tissue sarcomas. This tumor grows slowly. Diffuse abdominal pain is its most frequent symptom and abdominal mass is the most common sign. Aggressive surgical treatment is basic to get a complete resection and a local disease control. This objective is difficult because of the large tumor size it gets in the retroperitoneal location and the multiorgan involvement that require the resection of a high percentage of contiguous organs. We report a case of a giant retroperitoneal liposarcoma presenting like continuous left hemiabdominal pain because of the visceral compression. The right kidney was involved and suffering from renal vessel enlargement without renal function. There is a high probability of microscopic residual disease and a good follow-up of the patients is necessary as well as an adjuvant radiation therapy in some cases.     

Compound implant to project the nasal tip

Use of a compound implant to project the nasal tip in cases of thick skin, a depressed or slightly descending tip, and a minimal bony hump is reported. This implant gives shape and projection, is easy to obtain, and is well tolerated by the organism. It is made of a strip of septal cartilage or silastic; the anterior end is covered by a portion of alar cartilage. There is a low percentage of complications with this technique.     

Priapism following continuous thoracic epidural anaesthesia: emergency or a benign condition?

Priapism is a rare complication of epidural anaesthesia, and the pathophysiology is poorly understood. In general, 95% of all priapism episodes is ischemic because of decreased penile blood flow, and therefore requires immediate treatment. A case is reported of a 45‐year‐old male patient in which a clear relation is demonstrated between continuous thoracic epidural analgesia and priapism after transabdominal nephrectomy. The level of epidural anaesthesia supports the theory that the erection is a consequence of increased penile blood flow, thus a relatively harmless condition. However, confirmation by serial cavernous blood gas analysis or colour duplex ultrasonography is mandatory. Until this hypothesis is confirmed, termination of epidural infusion is advised as a primary treatment.     

Surgical treatment of Barrett carcinoma

Barrett-carcinoma is a type of adenocarcinoma of the distal esophagus and the cardia. Barrett-esophagus is defined by the histologic presence of specialized epithelium with intestinal metaplasia. As a consequence Barrett-carcinoma has a close relationship to the adenocarcinoma of the cardia and is very often part of the cardiacarcinoma type I. The aim of the surgical therapy is a radical R0-resection of the tumor including the lymphatic drainage area. This aim is accomplished among different authors by different surgical concepts. One is the radical transhiatal subtotal esophagectomy with lymphadenectomy in the lower mediastinum and the upper abdominal compartments. The other concept is a transthoracic en-bloc esophagectomy. Both resection procedures are usually completed by gastric pull up reconstruction. Currently a sophisticated preoperative staging is followed by distinguished indication and therapy depending on tumor status, risk factors of the patient and on the international classification of the cardia carcinoma (Siewert). When a R0-resection is impossible, a neoadjuvant radiochemotherapy should be performed.     

Management of humeral fracture nonunion in severe osteoporosis by a combination of locking plating and intramedullary fibular grafting

Nonunion of the humerus in a severely osteoporotic bone is a likely event especially if the fracture is transverse. The management of such a combination is a challenge. Most of the conventional fixation methods are unlikely to succeed as the bone failure precedes implant failure in osteoporosis. The challenge is further compounded in severe osteoporosis when the cortical thickness is affected more severely. We used a combination of an intramedullary fibula with a locking plate in 5 cases. The results show that it may be a good combination in such situations as the bone strength is augmented and the plate pullout is less likely.     

Thumb reconstruction in emergency, not including replantation

Many articles have discussed secondary thumb reconstruction but only few have been devoted to acute reconstruction. We propose to artificially separate four circumstances: (i) the thumb is preservable without associated trauma of the fingers. The rule is not to burn the bridge of secondary reconstruction; (ii) the thumb is preservable but a neighboring finger is seriously injured and functionally condemned. The finger has to be used as a "bank" to borrow the necessary anatomical structures for reconstruction of the thumb; (iii) the thumb is not preservable and the lesions of a neighboring finger allow to use it for a pollicization. The difficult decision is between the immediate transposition or maintenance for secondary pollicization. Only finger devascularization is a clear indication for acute pollicization; (iv) Finally when the thumb is not preservable and there is no associate finger injury, it is difficult to assess and inform sufficiently the patient to take a decision. Secondary thumb reconstruction is the best choice.     

Transfer of skills from the experimental model to the patients

Laparoscopy is a major part of urologists’ daily practice. It is becoming more and more popular and interest in it is increasing, as is the number of urologists attracted by it. Patients also frequently demand a treatment through a laparoscopic approach. Nevertheless, laparoscopy is a physically and technically demanding surgery. It has been proven that it has a long learning curve with a high complication rate at the beginning. Thus, there is need for a training program that can effectively reduce its time of apprenticeship. The learning path is a multistep process that involves several phases. The pelvic trainer is the first step of this path that is made with increasing dif.culty. Gradually and gently the trainee faces up to different levels under the guidance of a mentor. At the end of training, trainees should be able to perform every procedure, both easy and dif.cult ones, by themselves.     

Compound implant to project the nasal tip

Use of a compound implant to project the nasal tip in cases of thick skin, a depressed or slightly descending tip, and a minimal bony hump is reported. This implant gives shape and projection, is easy to obtain, and is well tolerated by the organism. It is made of a strip of septal cartilage or silastic; the anterior end is covered by a portion of alar cartilage. There is a low percentage of complications with this technique.     

Nasal glioma and encephalocele: two separate entities. Report of two cases

The term "nasal glioma" is a confusing misnomer as it implies a neoplastic condition with malignant potential, which it is not. Nasal glioma is a rare development abnormality and should be differentiated from glioma, which is a malignant tumor of the brain, and from a primary encephalocele, which is herniation of the cranial contents through a bone defect in the skull, through which it retains an intact connection with the central nervous system. Two cases of nasal glioma, one with and one without intracranial connections, are described and the literature is reviewed.     

Fine needle aspiration of the solitary pulmonary nodule

Percutaneous transthoracic needle biopsy is a well-established method of obtaining cytologic and histologic samples from a pulmonary nodule. Properly performed, needle biopsy is a simple and safe procedure. Pneumothorax is the most common complication, which, if symptomatic or large, is easily treated by chest tube insertion or aspiration. Minor hemorrhage and hemoptysis is the other common complication, which is rarely serious. Rare complications include air embolism and needle tract metastases. Needle biopsy has a high sensitivity and specificity for malignancy. For benign lesion, a specific diagnosis is less common, although with core needle biopsy, the yield of a specific benign diagnosis is increased.