Physico-chemical properties and optimization of the deformable FlexyDos3D radiation dosimeter

Deformable 3D radiation dosimetry is receiving growing interest for the validation of image-guided radiotherapy treatments (IGRT) of moving and deformable targets. Previously, a proof-of-concept of a flexible anthropomorphic 3D dosimeter called 'FlexyDos3D' has been demonstrated. One of the concerns with respect to the FlexyDos3D dosimeter is its dose-response instability. The effect of different formulations of the dosimeter on its stability were investigated. A stable formulation for the dosimeter was found by optimising the ratios of curing agent and base of the silicone matrix between 3% and 4.5% [w/w] curing agent. The effects of elevated curing temperatures and times upon the dosimetric properties were also investigated and the dose-response was found to be independent of curing times for curing times over an hour at 120 °C. ¹H NMR spectra of the dosimeter chemical constituents and the effect of radiation dose were determined. The evaporation and diffusion rates of chloroform in the dosimeter were determined and are the likely cause of the dosimeters depth-dose profile uncertainties. A composition for a stable silicone dosimeter which can be cured quickly at elevated temperatures was found, demonstrating the potential for 3D printing of patient-specific dosimeters. However, it is suggested that another radical initiator be used in future formulations of the dosimeter.

Gardner Transition in Physical Dimensions

The Gardner transition is the transition that at mean-field level separates a stable glass phase from a marginally stable phase. This transition has similarities with the de Almeida-Thouless transition of spin glasses. We have studied a well-understood problem, that of disks moving in a narrow channel, which shows many features usually associated with the Gardner transition. We show that some of these features are artifacts that arise when a disk escapes its local cage during the quench to higher densities. There is evidence that the Gardner transition becomes an avoided transition, in that the correlation length becomes quite large, of order 15 particle diameters, even in our quasi-one-dimensional system.

The need for rigid fixation of combined parasymphyseal and bilateral subcondylar fractures

Both miniplate and larger fracture plate fixation techniques have been utilized successfully in the treatment of mandibular fractures. Parasymphyseal fractures which occur in conjunction with bilateral subcondylar fractures, however, represent a special fracture pattern that is not well managed with miniplate fixation. Miniplates do not have the tensile strength to resist the strong, muscular-deforming forces that act on these fractures. This fracture pattern is best managed with anatomic symphyseal reduction and internal fixation with a 2.7 mm mandibular fracture plate and a 2.0 mm tension band plate. The subcondylar fractures can then be managed with either intermaxillary fixation or open reduction. This approach provides good functional results and can prevent late complications.

Intracranial migration of halo fixation pins: a complication of using an extraoral distraction device

OBJECTIVE

Distraction osteogenesis is a well-accepted technique in the treatment of patients with hypoplastic craniofacial components. Complications of distraction osteogenesis are well described in the literature. We describe a complication of using an external distraction device in a 9-year-old girl with Pfeiffer.

INTERVENTION AND RESULTS

A modified Lefort III osteotomy was performed for maxillary hypoplasia with application of an external distraction halo device by a pediatric neurosurgeon. A postoperative computed tomography (CT) scan showed 0.5-cm skull penetration of the cranial pins. The pins were repositioned and the patient was followed up on a regular basis until discharge from the hospital. At 3-week follow-up, a CT scan of the head showed migration of the pins 1.5 cm intracranially. The halo was removed and repositioned at a different site. No detectable neurological sequelae from the pin penetration were noted. The patient developed cellulitis at the site of the penetration and was admitted to the hospital for a course of intravenous antibiotics. There were no other complications, and the rest of her treatment course proceeded as planned. A review of the literature on complications of halo usage as well as suggestions for their management in association with distraction osteogenesis is described.

Carpal compression test and pressure provocative test in veterans with median-distribution paresthesias

We investigated the value of the carpal compression test (CCT) and the pressure provocative test (PPT) in predicting carpal tunnel syndrome (CTS) in a predominantly male population of veterans. We performed a prospective, blinded comparison of these clinical diagnostic tests with neurophysiological testing. One cohort of 135 consecutive patients was assessed with the CCT; a separate cohort of 134 consecutive patients was assessed with the PPT. Of these 269 patients, 58.4% had electrodiagnostically confirmed CTS. The sensitivity of the CCT was 52.5%, specificity was 61.8%, positive predictive value was 66.6%, and the negative predictive value was 47. 2%. The sensitivity of the PPT was 54.5%, specificity was 68.4%, positive predictive value was 70%, and the negative predictive value was 52.7%. The CCT and PPT had minimal utility in predicting electrodiagnostically confirmed CTS. In a subset of the CCT cohort, 86 consecutive veterans were also evaluated in relation to a clinical gold standard. Of these patients, 60% had CTS based on this gold standard. CCT sensitivity was 53.8%, specificity was 61.8%, positive predictive value was 68.3%, and negative predictive value was 46.7%. The CCT thus had marginal utility in predicting CTS based on a clinical gold standard.

Secondary fractures of Le Fort I osteotomy

PURPOSE

To report the ophthalmic complications of Le Fort I osteotomy for the correction of dentofacial deformities and to determine the maximal compressive loads applied during pterygomaxillary separation in a cadaver model.

METHODS

Two cases of ophthalmic complications arising after Le Fort I osteotomy are reported. Le Fort I osteotomy was performed on five cadavers. The maximal compressive load applied during pterygomaxillary separation was recorded with a 10 kN (3,000 lbf) load cell of a MTS Mini-Bionix servo-hydraulic machine (MTS, Eden Prairie, MN, U.S.A.). A paired t test was used to compare forces applied to the right and left sides. Computed tomography scans of each specimen were obtained after Le Fort I osteotomy to document secondary fractures. The skulls were subsequently stained with 1% fuschin red to highlight secondary fractures.

RESULTS

Maximum compressive loads during pterygomaxillary separation ranged from 22 N (5.0 lbf) to 162 N (36.5 lbf), with an average of 106 N (23.8 lbf) (SD 47.6 N [10.7 lbf]). Forces applied on the first operative side were significantly greater than forces applied on the second operative side (p = 0.0034). Secondary fractures were found in three specimens by computed tomography and in two specimens by 1% fuschin red. All secondary fractures occurred on the second operative side.

CONCLUSION

Secondary fractures in the Le Fort I osteotomy procedures occurred on the side opposite the greater maximal compressive load and on the second operative side.

Early recovery after endoscopic vs. short-incision open carpal tunnel release

Endoscopic carpal tunnel release has been claimed to offer improvement in recovery time and postoperative discomfort over open carpal tunnel release. Short-incision open carpal tunnel release has been claimed to offer recoveries comparable with endoscopic techniques. Patients receiving carpal tunnel surgery were randomized to short-incision open release or single-portal endoscopic release. Preoperative and postoperative evaluation included grip and pinch strength measurements and patient completion of a questionnaire regarding symptoms and function. Thirty-six operated hands completed evaluation, including 22 endoscopic and 14 open releases. Early grip and pinch strength after endoscopic carpal tunnel release were improved significantly over short-incision open release (p < 0.05). Subjective evaluation indicated a trend toward improved symptoms and function with endoscopic over short-incision open carpal tunnel release. Endoscopic carpal tunnel release provides faster recovery of strength than short-incision open carpal tunnel release and improves early postoperative comfort and function to a small degree.

Use of the radial forearm microvascular free-flap graft for cranial base reconstruction

OBJECT

Reconstruction of the cranial base after resection of complex lesions requires creation of both a vascularized barrier to cerebrospinal fluid (CSF) leakage and tailored filling of operative defects. The authors describe the use of radial forearm microvascular free-flap grafts to reconstruct skull base lesions, to fill small tissue defects, and to provide an excellent barrier against CSF leakage.

METHODS

Ten patients underwent 11 skull base procedures including placement of microvascular free-flap grafts harvested from the forearm and featuring the radial artery and its accompanying venae comitantes. Operations included six craniofacial, three lateral skull base, and two transoral procedures for various diseases. Excellent results were obtained, with no persistent CSF leaks, no flap failures, and no operative infections. One temporary CSF leak was easily repaired with flap repositioning, and at one flap donor site minor wound breakdown was observed. One patient underwent a second procedure for tumor recurrence and CSF leakage at a site distant from the original operation.

CONCLUSIONS

Microvascular free tissue transfer reconstruction of skull base defects by using the radial forearm flap provides a safe, reliable, low-morbidity method for reconstructing the skull base and is ideally suited to "low-volume" defects.

Closed rupture of the deep transverse metacarpal ligament: diagnosis and management

Closed rupture of the deep transverse metacarpal ligament (DTML) is an unusual injury. We have managed 2 patients with closed rupture of the DTML between the ring and small fingers resulting from crush injuries to the hand. Both patients presented with painful ulnar deviation of the small finger with extension. The diagnosis was confirmed by exploration through a volar incision. Repair of the ligament with use of the adjacent A1 pulleys to butress the repair was successful in both patients and restored a painless finger flexion-extension arc. Closed rupture of the DTML can be confused with a metacarpophalangeal joint collateral ligament rupture due to the characteristic deviation of the small finger.

Recurrent carpal tunnel syndrome following endoscopic carpal tunnel release: a preliminary report

Persistent or recurrent symptoms following endoscopic carpal tunnel release have been reported in 0.5% to 3% of patients undergoing this procedure. Unfortunately, preoperative risk factors for this complication have not been defined. We reviewed the records of 126 consecutive patients who underwent Agee single-portal endoscopic carpal tunnel release between June 1994 and March 1997. Five patients and six hands required subsequent open carpal tunnel release for persistent or recurrent carpal tunnel syndrome. Fulminant synovitis was identified during open carpal tunnel release in all reexplored patients, and four of the six hands were cured with open release and synovectomy. No recurrences were identified in the group of patients who presented with unilateral carpal tunnel syndrome. The presence of bilateral carpal tunnel syndrome may be a risk factor for persistent or recurrent carpal tunnel syndrome following endoscopic carpal tunnel release.

A safe, reliable method for skin-graft coverage of the radial forearm donor site

Delayed donor-site healing remains one of the most significant disadvantages of the radial forearm free flap. In an effort to decrease morbidity at the donor site, the authors adopted a closure technique that utilized the flexor digitorum sublimis (FDS) and flexor pollicis longus (FPL) muscle bellies to cover the flexor carpi radialis (FCR) tendon prior to placement of a split-thickness skin graft. While this approach eliminated tendon exposure, two patients with postoperative median-nerve compression forced a modification of this technique. The authors now detach the radial attachment of the FDS muscle and mobilize the median nerve away from the underside of the muscle, to prevent kinking of the nerve when the FDS and FPL muscle bellies are sewn together. With these modifications, the technique retains its efficacy, but with an improved margin of safety for the median nerve.

Successful hand revascularization with urokinase following a crush injury

Acute hand ischemia is a medical emergency requiring immediate treatment. We report a case of acute hand ischemia due to a crush injury of the wrist. Management with urokinase was successful in reestablishing flow to the ulnar artery and the digital vessels. In the setting of acute trauma with extensive thrombosis of the vessels of the hand, thrombolytic therapy may offer a better treatment option than surgical exploration with bypass grafting.

A new flap for nasal tip reconstruction

Aesthetic reconstruction of tumor defects of the nasal tip and supratip areas remains a challenge. Because of our dissatisfaction with the current reconstructive options, we have developed a modification of the nasalis flap based on the angular artery for the management of nasal tip defects. This is an axial flap-pattern that rotates toward the midline and nasal tip, leaving donor scars in the nasojugal and alar creases. A second rotation flap from the alar groove fills the donor defect in the nasojugal region to minimize scarring. We have utilized this flap 19 times in 18 consecutive patients with nasal tip and supratip tumor defects with follow-up ranging from 10 to 72 months. Donor scars are well concealed and nasal contour is minimally altered. Color and texture matches are excellent, and the pincushion deformity has been eliminated. On the basis of these results, we believe the modified nasalis flap is ideally suited for nasal tip reconstruction.

The use of intra-arterial urokinase in the management of hand ischemia secondary to palmar and digital arterial occlusion

Impending gangrene of the hand or digits secondary to palmar or digital artery occlusion can be a devastating complication of upper extremity thromboembolic or atheroembolic disease. Over the past 7 years, 9 patients with severe unilateral hand ischemia and impending tissue loss secondary to distal forearm, palmar arch, and digital artery occlusion were managed with intra-arterial urokinase (UK) infusion. The etiology of the ischemia was thromboembolism in 3 patients, atheroembolism in 2, and traumatic ulnar artery occlusion ("hypothenar hammer syndrome") in the remaining 4 patients. Initial high-dose UK was administered in 3 patients (240,000 U per hour for 2 hours) and all 9 patients were maintained on 80,000 to 120,000 U per hour until clot lysis occurred or until a minimum dose of 600,000 U had been given without clinical improvement. Following UK therapy, the 3 patients with thromboemboli had angiographic demonstration of clot lysis as well as complete resolution of ischemia. The 2 patients with atheroemboli showed no angiographic or clinical improvement, and both required surgical intervention. Angiographic improvement was demonstrated in only 1 patient with traumatic ulnar artery occlusion, although 3 of the 4 patients were clinically improved. A pericatheter thrombosis due to insufficient heparinization and a subcutaneous abscess at the femoral artery puncture site were the only complications of UK infusion. No hemorrhagic complications occurred and no adverse effects of lytic therapy were documented in patients who subsequently required surgery. UK is an effective treatment for recent thromboembolism, because it lyses unorganized thrombi. It is ineffective for treatment of organized thrombi or atheroemboli. Because the etiology of acute hand ischemia is not always obvious at the time of presentation, a trial of UK infusion is warranted, because it is relatively safe and its use may obviate the need for complex microsurgical reconstruction.

A 32-year follow-up of lunate excision for Kienbock's disease: a case report and a review of results from excision and other treatment methods

Lunate excision alone is seldom utilized in the management of Kienbock's disease due to concerns about progressive carpal collapse following removal of this central carpal bone. We report a 32-year follow-up of a patient who underwent lunate excision only for treatment of Kienbock's disease with a successful outcome. Although lunate excision is thought to be associated with a high failure rate, a review of the literature suggests that success rates following lunate excision are comparable to those reported for other more conventional techniques such as radial shortening, ulnar lengthening, limited carpal fusions, and proximal row carpectomy. The current perception that lunate excision is associated with a high failure rate is not supported in the literature. As such, it may not be appropriate to assign this operation to the category of "historical interest only."

Are the palmar cutaneous nerves safe during standard carpal tunnel release?

An incision in the axis of the ring finger is thought to be the safest for carpal tunnel release based on cadaveric studies that suggest that the palmar cutaneous nerves do not cross into this area. Despite the use of this incision, persistent postoperative scar tenderness has been reported in up to 36% of patients following standard carpal tunnel release. For this reason, an investigation was undertaken to determine the presence of palmar cutaneous nerves in this incision. Random biopsies of transversely oriented fibrous bands in the subcutaneous tissue were taken during 15 open carpal tunnel releases. In every patient, at least one biopsy was positive for peripheral nerve tissue. These findings, combined with previous cadaveric studies, suggest that a "safe" palmar incision that will avoid injury to palmar cutaneous nerves does not exist. Carpal tunnel release techniques that avoid a palmar incision may lessen postoperative morbidity by avoiding injury to these small cutaneous nerves.

Is training in endoscopic carpal tunnel release appropriate for residents?

Based on the relatively high incidence of complications for surgeons initially learning the technique, endoscopic carpal tunnel release is thought to have a steep learning curve. To determine if endoscopic carpal tunnel release can be safely performed by trainees, the outcomes of 84 patients who underwent endoscopic carpal tunnel release performed by a chief resident or hand fellow in a supervised setting were reviewed. All but 1 patient had uneventful procedures and complete resolution of preoperative symptoms. One patient with persistent symptoms represented the only complication. At reexploration through a standard palmar incision, the transverse carpal ligament was found to have been completely divided and fulminant tenosynovitis surrounding the nerve and flexor tendons was presumed to be the cause of his persistent symptoms. It appears that endoscopic carpal tunnel release can be safely performed by chief residents in a supervised clinical setting. Given that this procedure has a high learning curve, repeated exposure during a residency training program may offer significant advantages over the current approach of training surgeons during a single cadaveric instructional course.

The management of unsalvageable free flaps

The loss of vascular flow in the early postoperative period will generally lead to free flap failure. When attempts at flap salvage are unsuccessful, conservative management with delayed flap debridement may be indicated. Seven unsalvageable free flaps were managed with observation and flap debridement 4 to 14 days following loss of vascular signals. At the time of debridement, six of the seven wounds had viable granulation tissue and were successfully closed with skin grafts. The seventh patient had loss of vascular flow to the free flap within 12 hr of surgery and, at the time of delayed debridement, had no evidence of granulation ingrowth. Local revascularization of flaps is known to occur and offers an explanation for these findings. Delayed debridement of unsalvageable free flaps is indicated for noncritical wounds, and may obviate the need for a second free-tissue transfer to obtain wound closure.

The role of vascular pedicle thrombectomy in the management of compromised free tissue transfers

Microvascular free tissue transfer has become a very reliable reconstructive technique. Occasionally, flap compromise will occur and will require urgent flap reexploration. In the setting of complete thrombosis of pedicle vessels, thrombectomy using Fogarty #2 and #3 catheters can be effective in restoring vascular patency. Seven flaps with arterial, venous, or both vessel thrombosis were managed with thrombectomy at the time of reexploration and anastomotic revision. Six of the flaps were completely salvaged and the seventh was partially salvaged. Promptness in reexploration increased the likelihood of complete flap salvage. The use of postthrombectomy heparinization was associated with a 50% complication rat in this series. Thrombectomy of free flap vessels can be safely performed and is associated with a low incidence of rethrombosis.

Efficacy of the Nissen fundoplication in the management of gastroesophageal reflux following esophageal atresia repair

From January 1974 to December 1988, 80 patients with esophageal atresia (EA) and tracheoesophageal fistula (TEF) were treated at the C.S. Mott Children's Hospital with division of their TEF and esophagoesophagostomy. Thirty-four in this group developed gastroesophageal reflux (GER). After an unsuccessful trial of medical management, 21 underwent Nissen fundoplication, and an additional child with refractory GER died intraoperatively before completion of her fundoplication. Following fundoplication, only eight patients had an uncomplicated course with elimination of reflux and no postoperative dysphagia. Wrap disruption and recurrent reflux occurred in 7 of the 21 (33%), a markedly higher incidence than the 10% figure seen in 220 children without EA who have undergone fundoplication at this institution. Upward tension on the wrap due to the presence of a shortened esophagus probably predisposes to an increased frequency of fundoplication failure in the EA child. In addition, postoperative dysphagia requiring prolonged gastrostomy feedings complicated eight otherwise successful initial or redo-fundoplications. Prolonged dysphagia in this group is likely related to the inability of the dyskinetic esophagus, common in EA, to overcome the increased resistance caused by the Nissen fundoplication. Three deaths (14%) from complications related to antireflux surgery occurred in the series. Although 15 of the 21 children (71%) eventually had excellent long-term results following initial or redo-fundoplication with elimination of reflux and normalization of oral intake, morbidity and mortality were clearly significant. Due to the high incidence of postoperative dysphagia and recurrent reflux, the transabdominal Nissen fundoplication may not be appropriate in EA patients.

Etiology and management of respiratory complications after repair of esophageal atresia with tracheoesophageal fistula

This article reviews the cause and management of respiratory symptoms after repair of esophageal atresia with tracheoesophageal fistula (TEF). Postoperative respiratory symptoms developed in 31 (46%) of 68 patients and included apnea and bradycardia, respiratory arrest, aspiration, and recurrent pneumonia. The respiratory symptoms were initially attributed to gastroesophageal reflux (GER) in 20 patients (64%), tracheomalacia in 4 patients (13%), recurrent TEF in 4 patients (13%), and anastomotic stricture in 3 patients (10%). Three patients with GER and the three patients with a stricture were initially managed nonoperatively. The remaining 25 patients underwent surgical correction of the underlying cause of the respiratory symptoms. Despite aggressive management of this problem, 14 (45%) of these 31 patients had persistent or recurrent respiratory symptoms. Although GER is the most common cause of respiratory complications in patients who have undergone prior TEF repair, other factors are often responsible for these symptoms and should not be overlooked.

Pericardial flap interposition for the definitive management of recurrent tracheoesophageal fistula

From 1974 to 1988, six children with fistula recurrence following primary tracheoesophageal fistula (TEF) repair have been managed at our hospital. Reclosure of the fistula with pleural flap interposition was used as the initial corrective procedure in five patients, with an 80% incidence of second TEF recurrences. Due to these discouraging results, we have abandoned this technique and instead favor fistula reclosure with interposition of a pedicle of vascularized pericardium between the esophageal and tracheal suture lines. The pericardial pedicle is easy to mobilize, effectively isolates the tracheal and esophageal suture lines, and eliminates the often difficult task of finding sufficient pleural tissue for fistula interposition in small infants. Furthermore, the vascularized pedicle serves as a template for the ingrowth of neomucosa from the existing esophageal mucosa should an anastomotic leak occur. Since adopting this approach, we have used this technique on four children, three of whom had second recurrences after pleural interposition, and have had no evidence of recurrent fistula formation at follow-up ranging from 2 to 6 years. With at least a 20% incidence of second recurrences reported following conventional management with fistula closure and pleural interposition, we believe use of a pericardial flap in the management of the recurrent TEF is the most appropriate surgical procedure.

Redo fundoplication in infants and children with recurrent gastroesophageal reflux

The Nissen fundoplication is well established as the surgical treatment for medically refractory gastroesophageal reflux (GER) in childhood. Recurrent GER following fundoplication is a challenging problem with a reported incidence ranging from 0% to 12%. From January 1974 to January 1989, 286 children have been treated for GER with Nissen fundoplication and gastrostomy tube placement at the University of Michigan C.S. Mott Children's Hospital; 242 of these children have been followed for an average of 30 months, the remaining 44 have been lost to follow-up. Twenty-nine children (12%) have developed recurrent reflux following fundoplication. Medical management with thickened upright feelings, gastrostomy feedings, or gastrojejunostomy tube feedings has been successful for 11 children with control of reflux symptoms. Five additional children who were treated nonoperatively died of coexistant medical problems within 2 months following documentation or recurrent reflux. The remaining 13 children have required redo fundoplication for wrap disruption or herniation, and an additional six children, initially treated at other institutions, have also undergone redo fundoplications. One other child treated at this hospital required redo fundoplication for a postoperative partial gastric volvulus causing gastric outlet obstruction. Of the 20 children who have undergone a second Nissen fundoplication, 16 (80%) are doing well without recurrent GER. Four children have developed recurrent GER with wrap disruption; 1 is doing well following a third fundoplication, 2 have been managed successfully with continuous feedings via gastrojejunostomy feeding tubes, and a fourth child died of complications related to a recurrent tracheoesophageal fistula. Conservative management with gastrojejunal tube feedings should be considered in the initial management of children with recurrent GER following fundoplication.(ABSTRACT TRUNCATED AT 250 WORDS)

Portal venous barium intravasation complicating barium enema examination

Venous intravasation of contrast is a potentially life-threatening complication of the barium enema examination. A patient in whom portal venous contrast intravasation was nearly fatal is presented, and the significant morbidity and mortality from this unusual event is reviewed. Since barium infiltration into the venous system almost always occurs in the setting of altered mucosal integrity, this examination should be used cautiously in patients with inflammatory bowel disease or diverticulitis. Prompt recognition and rapid resuscitation are critical to the survival of patients with contrast intravasation.

Traumatic pneumoperitoneum. Implications of computed tomography diagnosis

Pneumoperitoneum detected on plain radiographs following blunt abdominal trauma is nearly pathognomonic of bowel perforation and usually mandates exploratory laparotomy. To determine the significance of computed tomography (CT)-detected pneumoperitoneum, we reviewed the clinical records and imaging studies of all trauma patients in our hospital over a seven-year period whose abdominal CT scans showed free intraperitoneal gas. Patients who had penetrating injuries or peritoneal lavage prior to CT were excluded. Of the 18 patients who met these inclusion criteria, surgically confirmed bowel injury was found in only four (22%). In the remaining 14 patients, no evidence of gastrointestinal perforation was found by exploratory laparotomy (2 patients), diagnostic peritoneal lavage (4 patients), GI studies and clinical follow-up (6 patients), or clinical follow-up alone (5 patients). Seven patients had a pneumothorax as a possible cause for pneumoperitoneum. Two additional patients were on mechanical ventilation. Unlike pneumoperitoneum seen on plain film, CT-detected pneumoperitoneum is not pathognomonic of bowel perforation. While laparotomy is not mandatory in the non-surgically explored patient, close clinical observation is essential, and additional diagnostic tests such as peritoneal lavage or radiographic contrast studies can be beneficial to confirm the absence of intestinal injury.

Long-term follow-up of brain-damaged children requiring feeding gastrostomy: should an antireflux procedure always be performed?

Due to the frequent presence of latent gastroesophageal reflux (GER) in mentally impaired children, it is now standard to perform upper gastrointestinal contrast (UGI) and pH probe studies in all children referred for feeding gastrostomy, even if they are without clinical evidence for GER. For patients with documented GER, an antireflux operation performed in conjunction with gastrostomy is usually considered mandatory. Some authors have suggested that a "protective" antireflux operation be performed at the time of gastrostomy placement in all brain-damaged children, citing a high incidence of postoperative GER in this group of patients following gastrostomy, even with a negative preoperative evaluation for GER. To evaluate this theory, we prospectively studied, over the past 6 years, all mentally retarded children referred for feeding gastrostomy with UGI contrast and esophageal pH probe studies. In total, 148 children were studied; 105 had a positive evaluation for GER and underwent gastrostomy and antireflux surgery. Of the 43 children with a negative preoperative evaluation for GER, 37 are doing well following gastrostomy alone without clinical reflux at an average follow-up of 21 months. Six of the 43 (14%) developed symptomatic GER occurring at an average of 10 months following gastrostomy placement. Five of these children have been successfully treated with an antireflux operation and the sixth patient has been successfully managed nonoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Lower extremity arterial disease in systemic lupus erythematosus

Lupus vasculitis primarily affects microvascular circulation, and large-vessel thrombosis is a rare complication of this disease. Large-vessel occlusive disease in systemic lupus erythematosus is most likely related to hypercoagulability in addition to immune complex-mediated endothelial damage. We describe the 11th and 12th patients reported to have systemic lupus erythematosus and macrovascular occlusive disease of the lower extremities. Our experience and a review of the literature suggest that, while aortoiliac disease is amenable to bypass or endarterectomy, infrainguinal disease is rarely correctable surgically, and amputation becomes necessary in most of these patients.

Fibroblast-mediated contraction in actinically exposed and actinically protected aging skin

The changes in skin morphology over time are a consequence of both chronologic aging and the accumulation of environmental exposure. Through observation, we know that actinic radiation intensifies the apparent aging of skin. We have investigated the effects of aging and actinic radiation on the ability of fibroblasts to contract collagen-fibroblast lattices. Preauricular and postauricular skin samples were obtained from eight patients aged 49 to 74 undergoing rhytidectomy. The samples were kept separate, and the fibroblasts were grown in culture. Lattices constructed with preauricular fibroblasts consistently contracted more than lattices containing postauricular fibroblasts. The difference in amount of contraction in 7 days between sites was greatest for the younger patients and decreased linearly as donor age increased (r = -0.96). This difference may be due to preauricular fibroblasts losing their ability to contract a lattice as aging skin is exposed to more actinic radiation.

Hirschsprung's disease in adolescents and adults

Hirschsprung's disease in the adolescent and adult is a rare and often misdiagnosed cause of lifelong refractory constipation. Two adolescent and three adult patients with Hirschsprung's disease treated between 1973 and 1987 at the University of Michigan Medical Center are reported. Each patient presented with chronic constipation requiring enemas, cathartics, and multiple hospital admissions for management. Diagnosis in each case was made with barium enema and full-thickness rectal biopsy. Four patients underwent endorectal pull-through procedures, all with good long-term results. The fifth patient, initially treated with a Duhamel retrorectal pull-through procedure, required reoperation for constipation secondary to a retained rectal septum. Review of 199 cases of adult Hirschsprung's disease enables comparison of the various operative procedures for this disorder with respect to postoperative complications and functional outcomes. Anorectal myectomy with low anterior resection, the Duhamel-Martin procedure, and the Soave endorectal pull-through procedure are the most acceptable methods for surgical management.

Descending necrotizing mediastinitis: transcervical drainage is not enough

One of the most lethal forms of mediastinitis is descending necrotizing mediastinitis, in which infection arising from the oropharynx spreads to the mediastinum. Two recently treated patients are reported, and the English-language literature on this disease is reviewed from 1960 to the present. Despite the development of computed tomographic scanning to aid in the early diagnosis of mediastinitis, the mortality for descending necrotizing mediastinitis has not changed over the past 30 years, in large part because of continued dependence on transcervical mediastinal drainage. Although transcervical drainage is usually effective in the treatment of acute mediastinitis due to a cervical esophageal perforation, this approach in the patient with descending necrotizing mediastinitis fails to provide adequate drainage and predisposes to sepsis and a poor outcome. In addition to cervical drainage, aggressive, early mediastinal exploration--debridement and drainage through a subxiphoid incision or thoracotomy--is advocated to salvage the patient with descending necrotizing mediastinitis.

Jejunogastric intussusception diagnosis and management

Jejunogastric intussusception is a rare complication following gastrojejunostomy, Bilroth II partial gastrectomy, and Roux-en-Y gastrojejunostomy. We report a recent patient with a retrograde gastrojejunal intussusception, the most common of the four anatomic variants of jejunogastric intussusception. It may present acutely as a surgical emergency with ischemic small bowel or chronically, with severe postprandial discomfort. Surgical correction is mandatory although controversy exists as to the most appropriate corrective procedure.

Obstructive jaundice secondary to chronic pancreatitis in children: report of two cases and review of the literature

Chronic pancreatitis is a rare childhood illness, most often presenting with nausea, vomiting, and recurrent abdominal pain. Obstructive jaundice secondary to biliary stricture is an uncommon manifestation of childhood pancreatitis, with only 11 patients previously described in the surgical literature. We report our experience with two additional children with jaundice secondary to pancreatitis and review the literature on this problem. Laboratory tests are often of little diagnostic value, and a high index of suspicion is essential for correct diagnosis. Endoscopic retrograde cholangiopancreatography is emerging as an extremely useful diagnostic study in these patients. The surgical management of this uncommon pediatric illness remains controversial.

Comparison of continuous and interrupted suture techniques in microvascular end-to-side anastomosis

To compare the speed and patency rates of the continuous and interrupted suture techniques in microvascular end-to-side anastomosis, 10 anastomoses utilizing each technique were performed using a femoral artery-superficial epigastric vein bypass model in Sprague-Dawley rats. The continuous suture technique was found to be almost twice as fast as the interrupted technique with no functional compromise. Patency for both techniques was 100 percent. These results are similar to those of several recent reports comparing the two techniques in end-to-end anastomosis and suggest that the continuous suture technique may be the most efficient technique for end-to-side anastomosis as well.