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Biomedical subjects

J A Knol

Publications and source records attributed to J A Knol.

At least 55 records · Page 3Linked to original sources
PubMed1986

Early variceal rebleeding after successful distal splenorenal shunt.

Of 77 patients with repeated variceal hemorrhage who underwent distal splenorenal shunt, five (6.5%) developed rebleeding despite a patent splenorenal anastomosis. Three of the five patients died. Early variceal rebleeding usually indicates shunt thrombosis but may occur with a patent anastomosis. Anatomic or functional left renal vein and/or splenic vein hypertension producing incomplete variceal decompression is generally the cause. Ineffective separation of the main portal vein from the gastrosplenic venous plexus may coexist and further intensify variceal congestion. Urgent angiographic studies and direct shunt catheterization with measurement of splenic vein, left renal vein, and inferior vena cava pressures should be performed to plan appropriate therapy. A significant gradient between the splenic and renal veins is evidence of an unsatisfactory anastomosis and should be managed by balloon angioplasty or reoperation. High splenic and left renal vein pressures with a gradient of more than 10 mm Hg between the renal vein and the inferior vena cava indicate renal vein hypertension. Initial therapy should include serial injection sclerotherapy, as renal vein hypertension will usually resolve over time as additional collaterals develop. However, persistent or recurrent variceal hemorrhage may require total portal decompression to bypass the restrictive left renal vein segment.

Adult↗
PubMed1986

Emergency gastrointestinal endoscopy and endoscopy for the emergency department.

Endoscopic procedures usually are not performed in the Emergency Department. However, on some occasions, it is essential that trained emergency physicians be able to perform endoscopic examinations. All physicians working in the Emergency Department should have an understanding of the role of endoscopy in the evaluation and treatment of gastrointestinal disorders, since in some cases, for example, those of massive upper and lower gastrointestinal hemorrhage, foreign body extraction, or functional and obstructive disorders of the colon, endoscopic procedures may be required on an emergency basis.

Colonoscopy↗
PubMed1986

Covert splenic abscess: a continuing challenge.

Although splenic abscess is a rare cause of intra-abdominal sepsis, the mortality rate remains high especially in patients with silent or covert lesions. The clinical presentation and course of five patients with overt splenic abscess and seven patients with covert splenic abscess seen during a thirty year period were analyzed. Average age of patients with overt lesions was 44.5 years. Direct extension from a contiguous source, hematogenous spread from a distant site (metastatic) and trauma comprised the known etiologies. Clinical features of localized left upper quadrant sepsis were commonly present but only one patient exhibited multiple organ failure. The clinical diagnosis was established preoperatively in four patients (80%) and all underwent splenectomy without mortality. All resected spleens contained solitary abscesses. In contrast, patients with covert lesions tended to be older (average age 56.1 years), uniformly exhibited multiple organ failure and rarely demonstrated local clinical findings of left upper quadrant sepsis. Trauma was a less common etiology than metastatic infection and direct extension. Four patients died without operation. Three patients underwent exploration for unrelated reasons, but the diagnosis of splenic abscess was made intraoperatively in only one patient. Mortality among patients with covert lesions was 86%. Multiple splenic abscesses were demonstrated in all patients with covert lesions. Splenic abscess presents as a spectrum of clinical disease. Solitary lesions can be readily diagnosed and treated by splenectomy. Multiple abscesses are usually covert, associated with multiple organ failure and highly lethal. The role of splenectomy in patients with covert lesions remains unknown.

Abscess↗
PubMed1985

Efficacy of pharmacologic glucagon in acute experimental pancreatitis.

Microcirculatory derangements in the pancreas associated with acute pancreatitis may contribute to a low-flow state and lead to pancreatic necrosis. This study investigated the effects of glucagon, a selective mesenteric arterial dilator, on pancreatic ischemia in canine bile-trypsin-induced pancreatitis (BTP). Measurements of cardiac Index (CI), total pancreatic blood flow (QP), pancreatic oxygen consumption (O2CP), and pancreatic arteriovenous shunt flow (QAVS) were obtained prior to and after inducing BTP. Bile-trypsin-induced pancreatitis was induced in 18 dogs. Nine received lactated Ringer's solution alone (LRPAN) at 6.5 mL/kg/hr, nine received lactated Ringer's solution plus continuous Intravenous (IV) glucagon hydrochloride (GLUPAN) at 1.0 micrograms/kg/min, and nine undergoing periportal dissection without BTP received IV glucagon (GLUCON). Following BTP, CI, QP, and O2CP decreased significantly and QAVS remained unchanged in crystalloid-treated animals (LRPAN). Glucagon administration (GLUPAN) transiently increased CI and QP but failed to improve O2CP and did not change QAVS. The decrease in O2CP observed after BTP in association with a constant QAVS suggests a metabolic block to oxygen uptake at the cellular level. Glucagon in pharmacologic doses does not reverse abnormalities in O2CP and is therefore of questionable physiologic benefit in the treatment of acute pancreatitis.

Acute Disease↗
PubMed1985

Morbid obesity treated by gastroplasty: radionuclide gastric emptying studies.

Mechanisms by which gastroplasty for morbid obesity causes weight loss are poorly understood. We studied the role of altered gastric emptying in 50 patients before surgery, 1-4 weeks after surgery, and 2-24 months after surgery using technetium-99m pentetate in water for liquid meals and a Tc-99m styrene divinylbenzene copolymer resin in oatmeal for semisolid meals. We determined the emptying half-times of the stomach before and after surgery in the proximal and distal compartments. The proximal compartment emptied promptly in the early and late postoperative periods. The distal compartment emptied liquids at rates similar to those before surgery, while the late postoperative emptying of semisolids was significantly faster. The stoma connecting the two compartments thus permits rapid transit of liquids and semisolids without delay of distal compartment emptying. No correlation was seen between the emptying half-times or changes thereof and eventual weight loss. Delayed gastric emptying is therefore not the mechanism for satiety and weight loss after gastroplasty has been performed.

Adult↗
PubMed1984

Efficacy of preoperative biliary tract decompression in patients with obstructive jaundice.

Fifty consecutive matched patients with benign or malignant biliary tract obstruction were compared to determine the efficacy of preoperative percutaneous biliary drainage (PBD). Twenty-five patients underwent PBD for an average of nine days before operation; 25 patients underwent percutaneous transhepatic cholangiography ( PTHC ) followed immediately by operation. Serum bilirubin levels before PTHC were 16.5 +/- 7.6 mg/dL and 14.9 +/- 7.6 mg/dL in PBD and non-PBD groups, respectively. Serum bilirubin levels decreased to 6.5 +/- 6.2 mg/dL preoperatively in patients having PBD. One week after operation, bilirubin levels were 4.2 +/- 4.3 mg/dL and 9.0 +/- 5.2 mg/dL in the PBD and non-PBD groups, respectively. Major morbidity (sepsis, abscess, renal failure, or bleeding) occurred in two patients (8%) having PBD and in 13 patients (52%) without PBD. One patient (4%) with PBD, and five patients (20%) without PBD, died. The mean hospital stay was shorter for the PBD group. Preoperative PBD reduces operative mortality and morbidity and results in a more rapid resolution of hyperbilirubinemia during the postoperative period.

Biliary Tract Surgical Procedures↗
PubMed1984

Complicated access for regional infusion chemotherapy. A consequence of variant hepatic artery anatomy.

Arterial access for regional infusion chemotherapy of primary or metastatic liver cancers may be complicated because of inadequate vessel size or variant hepatic artery anatomy. Recently, an unusual case required that we devise an extemporaneous method of single-catheter access. This approach may, in selected cases, be an acceptable and safe alternative to a more traditional access technique.

Adenocarcinoma↗
PubMed1984

Effects of portacaval shunt and portacaval transposition on hepatocellular and hepatic reticuloendothelial cell activity in the dog.

UNLABELLED: Quantitative reduction of portal blood flow following a portacaval shunt (PCS) adversely affects hepatocyte function, but does not alter HRES activity [L. P. Edgcomb , J. A. Knol , and F. E. Eckhauser . J. Surg . Res. 33: 233, 1982]. To determine whether similar changes occur after qualitative alteration of portal blood flow, portacaval transpositions (PCT) were constructed in six conditioned mongrel dogs. Estimated hepatic blood flow (EHBF) was determined scintigraphically by the rate of hepatic uptake of a 500-microCi dose of 99mTc -sulfur colloid (Tsc). Hepatic reticuloendothelial cell (RES) phagocytic (PI) and degradative (DI) indices were calculated from the half-time blood disappearance of 131I-labeled RES test lipid emulsion, and the half-time urine appearance of free 131I, respectively. Opsonic activity (OI) was determined by gelatin latex particle agglutination and normalized to control values. Hepatocellular function was assessed by serial determinations of albumin (Alb), and pyruvic and glutamic oxaloacetic transaminases (SGPT and SGOT). All studies were performed prior to and at 3, 6, and 9 weeks following PCS or PCT. CONCLUSIONS: In the dog, neither PCS nor PCT adversely affected HRES activity. Hepatocellular function and OI remained unchanged following PCT but deteriorated significantly after PCS. Observed changes in hepatocyte function and OI following PCS suggest that hepatocellular integrity and serum opsonic activity may be interrelated.

Alanine Transaminase↗
PubMed1984

Endoscopy of the partitioned stomach.

Fiberoptic endoscopy is an important diagnostic modality for evaluation of the patient with upper gastrointestinal (GI) tract symptoms following gastric bypass and gastroplasty. During a 3-year period, 182 patients underwent gastric partitioning procedures and 22 patients (12%) developed upper GI symptoms requiring endoscopic evaluation. Eight patients had undergone Mason vertical banded gastroplasty, 12 patients had undergone Gomez gastroplasty, and two patients had undergone Roux-en-Y gastric bypass. In four of five patients with abdominal pain, gastritis of the proximal pouch was observed. Of the two patients with symptoms of obstruction of the proximal gastric outlet, one patient was found to have a cherry pit occluding the channel. Intraoperative endoscopy was performed in one patient who developed upper GI bleeding after Roux-en-Y gastric bypass, the pylorus was scarred and stenotic and multiple superficial ulcerations were seen in the excluded distal stomach. In eight patients with symptoms suggestive of channel stenosis, four were found to have a stenotic channel and underwent endoscopic dilation of the channel. Upper GI endoscopy was performed in eight patients with Gomez gastroplasty to confirm suspected dilatation of the channel between the upper and lower gastric pouches. Upper GI contrast studies did not estimate accurately the diameter of the channel as determined during endoscopy. No complications were observed following any of the endoscopic procedures. As the collective experience with gastric partitioning procedures increases, the need for endoscopic examinations of the upper GI tract will also increase. Endoscopists should be familiar with the altered gastric anatomy and with the spectrum of upper GI lesions that develop following these operations.

Constriction, Pathologic↗
PubMed1984

A modified suture technique for tube gastrostomy.

A modified suture technique for tube gastrostomy is presented which promotes better exposure for suture placement and results in a close continuous seal between the stomach and the abdominal wall.

Abdominal Muscles↗
PubMed1984

Patient selection and survival after peritoneovenous shunting for nonmalignant ascites.

Patient selection and survival after peritoneovenous shunting for nonmalignant ascites was assessed in 30 patients undergoing 44 peritoneovenous shunting procedures over a 5-year period. Indications for peritoneovenous shunting included refractory ascites alone, refractory ascites complicated by hepatorenal syndrome, and nonrefractory but recurrent ascites. Fifty-six percent of shunting procedures were complicated by shunt malfunction and an additional 13% ended in shunt removal or ligation. Serious perioperative morbidity occurred in 47% of patients. Mean duration of shunt function was significantly less (p less than 0.05) in the patients with hepatorenal syndrome (15 +/- 5 days) compared to the patients with refractory ascites alone (45 +/- 13 days), or the patients with nonrefractory ascites (64 +/- 34 days). Mean survival was 265 +/- 87 days. Survival of patients with nonrefractory ascites (767 +/- 214 days) was significantly longer (p less than 0.05) than that seen in patients with hepatorenal syndrome (28 +/- 5 days) or in patients with refractory ascites alone (256 +/- 148 days). Combined inhospital mortality was 30%. It was significantly greater (p less than 0.05) in patients with hepatorenal syndrome (70%) than in patients with refractory ascites alone (14%) or in patients with nonrefractory ascites (0%). We conclude that patient selection significantly influences survival after peritoneovenous shunting and may account for the varying results reported by other groups.

Adult↗
PubMed1984

Near-total pancreatectomy for chronic pancreatitis.

Eighty-seven patients underwent distal subtotal or near-total (80% to 95%) pancreatectomy (NTP) during a 25-year period for management of intractable pain resulting from chronic pancreatitis. Alcoholism affected the majority of patients and 20% of cases were idiopathic in origin. Ten patients (12%) exhibited insulin-requiring diabetes before operation. The perioperative mortality rate was 3.4%. Significant improvement or complete pain relief was achieved in 75% of patients while 14% remained narcotic dependent. Forty-four patients (51%) required insulin postoperatively, with an average insulin requirement of 35 U per day. Thirty late deaths occurred 2 to 15 years after operation, 12 (40%) of which were related to complications of pancreatic insufficiency or persistent alcoholism. Five patients (8.5%) required completion pancreatectomy 6 months to 4 years after NTP for complications relating to persistent pancreatitis. NTP provides effective pain relief in the majority of patients with chronic pancreatitis. While this procedure can be performed with a low operative mortality rate, the high incidence of endocrine and exocrine insufficiency after operation may contribute to late deaths. Consequently, this procedure should be performed only when the underlying disease has functionally destroyed the pancreas or when lesser procedures have failed to provide adequate pain relief.

Adolescent↗
PubMed1984

Hydrostatic balloon dilatation for stomal stenosis after gastric partitioning.

Hydrostatic balloon dilatation has been used successfully to treat several patients with stomal stenosis occurring as a late complication of gastroplasty. The technique of hydrostatic balloon dilatation practiced in this institution is reviewed in detail. This technique appears to offer several advantages over previous techniques: 1) the procedure can be accomplished with intravenous sedation eliminating the need for general anesthesia; 2) trauma to the gastric channel is minimized because no attempt is made to manipulate the endoscope through the stoma into the distal stomach; 3) radiopaque markers on the polyethylene balloon catheter permit easy and accurate positioning of the balloon within the gastric channel; 4) the low compliance characteristics of the polyethylene balloon used permit inflation to a predetermined outer diameter with minimum risk of balloon deformity or overdistention and rupture; and 5) the procedure is easily standardized and can therefore be expected to yield reproducible results. Late stomal stenosis after gastric partitioning may respond to conservative therapy including nutritional support and dietary counselling. Hydrostatic balloon dilatation should be considered as the preferred method of stomal dilatation in patients refractory to alternative forms of management.

Adult↗
PubMed1984

Intraoperative fiberoptic endoscopy.

Conventional endoscopy is an indispensable tool in the diagnosis and management of many patients with gastrointestinal disease. Intraoperative use of the fiberoptic endoscope permits direct visualization of the mucosal surface, eliminating the need for enterotomy in many cases. Over a 4.5-year period, 32 patients underwent gastrointestinal endoscopy during laparotomy for a wide variety of surgical problems. In 15 cases, obscure or unknown sites of upper and lower gastrointestinal bleeding were localized. Replacement of percutaneously placed biliary drainage tubes was facilitated in four cases. In three patients artifactual lesions suggested by gastrointestinal (GI) contrast studies were excluded with intraoperative endoscopy at the time of exploratory laparotomy, and in four cases, retained foreign bodies were recovered easily without the need for enterotomy. In six additional patients intraoperative endoscopy was used to localize nonpalpable colon polyps or to determine the extent of mucosal ulceration. The average time for an intraoperative fiberoptic endoscopic examination was 20 minutes. No complications resulted from this technique. In summary, intraoperative fiberoptic endoscopy is of definite value in assessing selected patients with difficult GI surgical problems encountered during laparotomy. This technique enhances the surgeon's ability to identify and treat inaccessible and occult GI lesions.

Adult↗
PubMed1984

Surgical treatment of necrotizing pancreatitis by marsupialization.

The ideal surgical treatment for necrotizing pancreatitis remains a matter of debate. To provide adequate drainage and egress for large fragments of devitalized pancreas as well as access for interval debridement, three patients with significant pancreatic necrosis underwent debridement of devitalized pancreas and open packing (marsupialization) of the lesser space. The etiologies of pancreatic necrosis included trauma in one patient, an infected pancreatic pseudocyst in another patient, and acute alcoholic pancreatitis in the third patient. After the initial operative procedure, patients were returned to the operating room at intervals of 2 to 5 days for further debridement and dressing changes. Clinical improvement was observed almost immediately after the initial procedure, although the rate of recovery varied from patient to patient. No deaths occurred. Two procedure-related complications occurred: development of a loculated fluid collection in the left paracolic gutter that required surgical drainage and an injury to the splenic artery requiring arteriorrhaphy . Late complications included a ventral hernia and a persistent duodenocutaneous fistula. Marsupialization along with limited debridement is recommended as an alternative to closed drainage of the peripancreatic space in patients with significant pancreatic necrosis.

Adult↗
PubMed1983

Low molecular weight dextran in experimental pancreatitis: effects on pancreatic microcirculation.

UNLABELLED: Although low molecular weight (LMW) dextran has been said to decrease the lethality of experimental acute pancreatitis (AP) by reversing stasis in the pancreatic microcirculation, the actual mechanism(s) of action is unknown. This investigation was designed to measure the effects of low molecular weight dextran on pancreatic capillary flow (QCAP) and arteriovenous shunt flow (QAVS), and on pancreatic oxygen consumption (O2CP) following bile-trypsin-induced AP in dogs. Total pancreatic blood flow (QT) was measured with an electromagnetic flow probe on the superior pancreaticoduodenal artery (SPDA). QAVS was measured by liver trapping of 99mTc-albumin microspheres after SPDA injection. QCAP was calculated as QT minus QAVS. Seventeen dogs were treated with lactated Ringer's (LR) solution at 6.5 ml/kg/hr; 10 dogs were treated with LMW dextran 10% in normal saline at 1.5 ml/kg/hr plus LR at 5.0 ml/kg/hr. Mean arterial and central venous pressures remained constant throughout the 4-hr experiment. In the dogs receiving LR only, QT decreased from 42.7 to 24.4 ml/min (P less than 0.001); QAVS remained constant at 1.35 +/- 0.04 ml/min. During the first 30 min O2CP decreased from 1.17 to 0.76 ml O2/min (P less than 0.05) and remained constant thereafter. LMW dextran treatment altered none of these hemodynamic or metabolic parameters significantly. CONCLUSIONS: bile trypsin AP in the dog causes significant decreases in QT and QCAP without altering QAVS. The decrease in O2CP in association with a constant QAVS suggests a metabolic block to oxygen uptake at the cellular level. Continuous infusion of LMW dextran at a dose of 1.5 ml/kg/hr in the dog does not reverse these abnormalities.

Acute Disease↗