With an archaeological history for over 4000 years in China, Chinese dates, were recognized as a member of jujube species, zizyphus genus, buckthorn family, rhamnales order, dicotyledoneae class, angiospermae phylum, and plant kingdom [6]. According to the size, color and shape of their fruits, over 400 cultivars of Chinese dates can be sub classified as big or small, red or green, spherical, oval, flat, horse tooth-shaped, dog head-shaped, pear-shaped and apple-shaped types. For a long time, Chinese dates are mainly grown in the middle-north China, including Hebei, He nan, Shan dong, Shanxi, Shaan xi, Gan shu and Xin jiang provinces (Fig. 2). Centuries ago they were introduced beyond Asia and are sporadically grown in southern Europe, northern Africa, and the southwestern United States. Currently, fruits of Chinese dates are commonly seen in the food markets all over the world. Dates palm, also called Persian dates, are planted mainly in the Middle East and belong to phoenix genus, palmae family.
Nutritional constituents of dates are determined as saccharides, vitamins, saponins, triterpenes, as well as alkaloids, flavonoids, glucosides, nucleosides, amino acids, amides, organic acids, and steroids [7,8]. Due to its plentiful bioactive compounds, dates are praised as natural vitamin pills and mineral element depot. In Chinese traditional medicine, multiple functions were described for dates, such as appetizing and invigorating the spleen, removing exhaustion and supplementing stamina, quieting heart and nourishing blood, improving appearance, and delaying senility, etc. Mounting evidences from modern pharmaceutical studies also indicates health benefits of dates, including the increase of intracellular cAMP, prevention of allergic reactions, inhibition of abnormal nerve conduction, protection of liver function, decrease of the sclerosis of vascular walls, modification of blood pressure, improvement of muscle power, induction of sedative-hypnotic effects, blockade of genetic mutation, alleviation of lipid per oxidation, and delay of tumor genesis [9,10].
Except eaten in fresh as snacks, dates are widely added as components in different types of foods, including candy, preserve, pudding, cake, paste, puree, honey, syrup, congee, porridge, soup, wine, and tea. Generally, date fruits are green and smooth when immature, turn dark red and wrinkle when ripe. Under the thin crisp coat there is rich fibrous pulp and a single hard Kernel(Fig. 3). Without enough cautions, the sharp ends of these kernels may cause severe injury to the human body. Especially in these big sized dates, their kernels are also correspondingly longer than average,and are more easily detained in the digestive tract [11]. For instance, the kernel of extra-grade HETIAN dates can reach 3-4 centimeters in size. It is always recommended to remove the kernels by tools like seeders and slicers before ingestion. Once the kernel was accidentally swallowed, perforation of digestive tract can be fairly expected.
Although most patients in our center are fully cured following the immediate operation, misdiagnosis may lead to peritonitis, intra-abdominal infection, bowel obstruction, septic shock or even death. The recovery period is pretty long and there is challenge for adhesive obstruction in the long term. Considering more cases of esophageal perforation is caused by accidentally swallowed date kernels, the economic cost are quite massive.
It were reported that old people or children are more jeopardized by date kernels induced perforations[12,13]. Consistently, patients in our report are more elder people (86% above 50) with an average of 58 years old. No children were reported as there is no pediatric surgical department in our hospital. Teeth loss, discordination of masticators, and malfunction of nervous reflex all contribute the high incidence of swallow accident when compared with young people. Besides the three natural strictures in esophagus, there are additional narrow sites including preventriculus, pylorus, anus, and ileocecal valve. Our report showed that most perforation led by date kernels occurred at distal or terminal ileum (93%). One explanation maybe the kernel tips were still wrapped with residual pulps when swallowing, while they were gradually exposed after decomposition by digestion. Also, the narrower cavity, less folds and thinner mucosa layer of ileum make it more vulnerable compared with jejunum. In addition, tonic contraction, segmental compress, rhythmic movement, peristaltic rush of small intestine, and the existence of ileocecal valve all help to increase local enteric pressure, leading to the puncture and incarceration of kernel tips in the ileum wall.
Kernel-induced perforation should be differentiated with appendicitis, especially for some old patients with amnesia who can not provide clear food history. Metastatic right lower abdominal pain, fixed tenderness at McBurney points , peritonitis, fever, and increased WBC counting are typical evidences for appendicitis, which can be confirmed as appendiceal thickening and stercoral obstruction by ultrasound or CT examinations [14]. Another differential disease is bowel obstruction and CT is of great value for the determination [15-18]. Not only the high density foreign object is too obvious in the CT image to confirm the diagnosis, but also the unique spindle shape of date kernels assist to the design and implements of the surgical plan. In our reports, two patients did not mention swallowing history of date kernel, thus were suspected as appendicitis at the beginning,but fortunately corrected by meticulous reading of CT images and supplemental inquiry of dietary history.
All patients diagnosed with kernel induced perforation require emergent surgery. Early operation decrease the leakage and intra- abdominal contamination, as the punctures are generally small because the impaction of sharp ends,but intestinal edema is not rare. Kernels should be extracted as intact as possible to avoid secondary injury and the puncture should be fixed carefully. No enterectomy and anastomosis were needed in our patients but they are sometimes required in severe situations [19]. It is critical to carefully check the full length of digestive tract, especially the contrary side of intestinal wall of first perforation to identify additional injuries, as detected by 6/14(42%)in our patients. Open procedures were performed in our center to ensure the thorough exploration and integral extraction of kernels. Laparoscopic approach has the advantages of less invasion and rapid recovery, and might be attempted in the future once the etiologic diagnosis and the kernel location were confirmed.